,,letters                               
,,on                                    
,,natural ,,magic1                      
,,addressed ,,to                        
,,sir ,,walter ,,scott1 ,,bart4         
,,by                       ,,sir ,,david
 ,,brewster1 ,,ll4,d41 ,f4,r4,s4        
,illustration3 ,three figures on        
hill-top saluting sunrise               
,,seventh ,,edition4                    
,,london3                  ,,william    
,,tegg ,,and ,co41 #he1 ,,queen         
,,street4                               
,,cheapside4                            
#ahef4          ,,contents4             
,,letter ,i4      ,extent and interest  
of the subject--,science employed by    
ancient governments to deceive and      
enslave their subjects--,influence    of
 the supernatural upon ignorant         
minds--,means    employed by the ancient
 magicians to establish    their        
authority--,derived from a knowledge of 
the phenomena    of ,nature--,from the  
influence of narcotic drugs    upon the 

victims of their delusion--,from every  
branch of                               
science--,acoustics--,hydrostatics--,mec
hanics--,optics--,m4    ,salverte's work
 on the occult sciences--,object of     
the following letters                   
,page #a        ,,letter ,,ii4      ,the
 eye the most important of our          
organs--,popular description    of      
it--,the eye is the most fertile source 
of mental    illusions--,disappearance  
of objects when their images fall       
upon the base of the optic              
nerve--,disappearance of objects    when
 seen obliquely--,deceptions arising    
from viewing    objects in a faint      
light--,luminous figures created by     
pressure on the eye1 either from        
external causes or from    the fulness  
of the blood-vessels--,ocular spectra or
 accidental    colours--,remarkable     
effects produced by intense             
light--,influence of the imagination in 
viewing these    spectra--,remarkable   
illusion produced by this affection     

of the eye--,duration of impressions of 
light on the                            
eye--,thaumatrope--,improvements upon it
 suggested--,disappearance    of halves 
of objects or of one of two             
persons--,insensibility    of the eye to
 particular colours--,remarkable        
optical illusion described              
#h      ,,letter ,,iii4      ,subject of
 spectral illusions--,recent and        
interesting case    of ,mrs4 ,a4--,her  
first illusion affecting the            
ear--,spectral    apparition of her     
husband--,spectral apparition of a      
cat--,apparition    of a near and living
 relation in grave-clothes1    seen in a
 looking-glass--,other illusions1       
affecting    the ear--,spectre of a     
deceased friend sitting in an           
easy-chair--,spectre of a coach-and-four
 filled with    skeletons--,accuracy and
 value of the preceding cases--,state of
    health under which they             
arose--,spectral apparitions are        
pictures on the retina--,the ideas of   

memory and imagination    are also      
pictures on the retina--,general views  
of    the subject--,approximate         
explanation of spectral apparitions  #cg
        ,,letter ,,iv4      ,science    
used as an instrument of                
imposture--,deceptions    with plane and
 concave mirrors practised by the       
ancients--,the    magician's            
mirror--,effects of concave             
mirrors--,arial    images--,images on   
smoke--,combination of    mirrors for   
producing pictures from living          
objects--,the    mysterious             
dagger--,ancient miracles with concave  
mirrors--,modern necromancy with them1  
as seen by ,cellini--,description    and
 effects of the magic                   
lantern--,improvements    upon          
it--,phantasmagoric exhibitions of      
,philipstall and others--,dr4 ,young's  
arrangement of    lenses1 c41 for the   
,phantasmagoria--,improvements          
suggested--,catadioptrical              
phantasmagoria for producing    the     

pictures from living objects--,method of
 cutting off    parts of the            
figures--,kircher's mysterious          
hand-writing on    the wall--,his hollow
 cylindrical mirror for arial           
images--,cylindrical    mirror for      
re-forming distorted pictures--,mirrors 
of variable curvature for producing     
caricatures            #ef              
,,letter ,v4      ,miscellaneous optical
 illusions--,conversions of cameos into 
intaglios1 or elevations into           
depressions1 and the                    
reverse--,explanation of this class of  
deceptions--,singular    effects of     
illumination with light of one simple   
colour--,lamps    for producing         
homogeneous yellow light--,methods    of
 increasing the effects of this         
exhibition--,method of    reading the   
inscription of coins in the dark--,art  
of    deciphering the effaced           
inscription of coins--,explanation    of
 these singular effects--,apparent      
motion of the eyes    in                

portraits--,remarkable examples of      
this--,apparent    motion of the        
features of a portrait1 when the eyes   
are    made to move--,remarkable        
experiment of breathing    light and    
darkness                                
#ih        ,,letter ,,vi4      ,natural 
phenomena marked with the               
marvellous--,spectre    of the ,brocken 
described--,analogous phenomena--,arial 
spectres seen in ,cumberland--,fata     
,morgana in    the ,straits of          
,messina--,objects below the horizon    
raised    and magnified by              
refraction--,singular example seen at   
,hastings--,dover ,castle seen through  
the hill on which it    stands--,erect  
and inverted images of distant ships    
seen    in the air--,similar phenomena  
seen in the ,arctic regions--,enchanted 
coast--,mr4 ,scoresby recognizes his    
father's    ship by its arial           
image--,images of cows seen in the      
air--,inverted    images of horses seen 
in ,south ,america--,lateral    images  

produced by refraction--,arial spectres 
by reflexion--,explanation of the       
preceding phenomena      #abg           
,,letter ,,vii4      ,illusions         
depending on the ear--,practised by the 
ancients--,speaking    and singing heads
 of the ancients--,exhibition    of the 
,invisible ,girl described and          
explained--,illusions    arising from   
the difficulty of determining the       
direction    of sounds--,singular       
example of this illusion--,nature of    
ventriloquism--,exhibitions of some of  
the most celebrated                     
ventriloquists--,m4 ,st4 ,gille--,louis 
,brabant--,m4    ,alexandre--,capt4     
,lyon's account of ,esquimaux           
ventriloquists #aeg    ,,letter ,,viii4 
,musical and harmonic sounds            
explained--,power of breaking    glasses
 with the voice--,musical sounds from   
the    vibration of a column of air--and
 of solid                               
bodies--,kaleidophone--,singular        
acoustic figures produced on    sand    

laid on vibrating plates of glass--and  
on stretched    membranes--,vibration of
 flat rulers and cylinders of           
glass--,production of silence from two  
sounds--,production    of darkness from 
two lights--,explanation of these       
singular effects--,acoustic             
automaton--,droz's bleating             
sheep--,maillardet's                    
singing-bird--,vaucanson's              
flute-player--,his    pipe and          
tabor-player--,baron ,kempelen's        
talking-engine--,kratzenstein's         
speaking-machine--,mr4    ,willis's     
researches                              
#agi        ,,letter ,,ix4              
,singular effects in nature depending on
 sound--,permanent    character of      
speech--,influence of great elevations  
on the    character of sounds1 and on   
the powers of speech--,power    of sound
 in throwing down buildings--,dog killed
    by sound--,sounds greatly changed   
under particular circumstances--,great  
audibility of sounds during the night   

explained--,sounds deadened in media of 
different    densities--,illustrated in 
the case of a glass of champagne--and   
in that of new-fallen snow--,remarkable 
echoes--,reverberations    of           
thunder--,subterranean                  
noises--,remarkable    one at the       
,solfaterra--,echo at the ,menai        
suspension    bridge--,temporary        
deafness produced in                    
diving-bells--,inaudibility    of       
particular sounds to particular         
ears--,vocal    powers of the statue of 
,memnon--,sounds in    granite          
rocks--,musical mountain of ,el-,nakous 
#bab        ,,letter ,x4                
,mechanical inventions of the ancients  
few in number--,ancient    and modern   
feats of strength--,feats of ,eckeberg  
particularly described--,general        
explanation of them--,real    feats of  
strength performed by ,thomas           
,topham--,remarkable    power of lifting
 heavy persons when the    lungs are    
inflated--,belzoni's feat of sustaining 

pyramids    of men--,deception of       
walking along the ceiling in an         
inverted position--,pneumatic apparatus 
in the foot of    the house-fly for     
enabling it to walk in opposition to    
gravity--,description of the analogous  
apparatus employed    by the gecko      
lizard for the same purpose--,apparatus 
used    by the ,echineis remora1 or     
sucking-fish                   #bdd     
,,letter ,,xi4      ,mechanical automata
 of the ancients--,moving               
tripods--,automata    of                
,ddalus--,wooden pigeon of              
,archytas--,automatic    clock of       
,charlemagne--,automata made by         
,turrianus for ,charles ,v4--,camus's   
automatic carriage    made for ,louis   
,,xiv4--,degenne's mechanical           
peacock--,vaucanson's    duck which ate 
and digested its food--,du    ,moulin's 
automata--,baron ,kempelen's automaton  
chess-player--,drawing    and writing   
automata--,maillardet's                 
conjurer--,benefits derived from the    

passion for automata--,examples    of   
wonderful machinery for useful          
purposes--,duncan's    tambouring       
machinery--,watt's statue-turning       
machinery--,babbage's calculating       
machinery                #bfd           
,,letter ,,xii4      ,wonders of        
chemistry--,origin1 progress1 and       
objects of    alchemy--,art of breathing
 fire--,employed by ,barchochebas1      
,eunus1 c4--,modern method--,art of     
walking    upon burning coals and       
red-hot iron1 and of plunging the       
hands in melted lead and boiling        
water--,singular property    of boiling 
tar--,workmen plunge their hands in     
melted copper--,trial of ordeal by      
fire--,aldini's incombustible           
dresses--,examples of their wonderful   
power in    resisting flame--,power of  
breathing and enduring air of    high   
temperatures--,experiments made by ,sir 
,joseph    ,banks1 ,sir ,charles        
,blagden1 and ,mr4 ,chantrey            
#bbg      ,,letter ,,xiii4              

,spontaneous combustion--,in the        
absorption of air by    powdered        
charcoal--and of hydrogen by spongy     
platinum--,dobereiner's                 
lamp--,spontaneous combustion in the    
bowels of the earth--,burning           
cliffs--,burning soil--,combustion      
without flame--,spontaneous combustion  
of human    beings--,countess           
,zangari--,grace ,pett--,natural        
fire-temples    of the                  
,guebres--,spontaneous fires in the     
,caspian    ,sea--,springs of           
inflammable gas near ,glasgow--,natural 
light-house of ,maracaybo--,new elastic 
fluids in the    cavities--of           
gems--,chemical operations going on in  
their    cavities--,explosions produced 
in them by heat--,remarkable    changes 
of colour from chemical causes--,effects
    of the nitrous oxide or ,paradise   
gas when    breathed--,remarkable cases 
described--,conclusion          #cac    
,,letters                               
,,on                                    

,,natural ,,magic2                      
,,addressed ,,to                        
,,sir ,,walter ,,scott1 ,,bart4         
,,letter ,i4     ,extent and interest of
 the subject--,science employed by      
ancient   governments to deceive and    
enslave their subjects--,influence   of 
the supernatural upon ignorant          
minds--,means employed by the   ancient 
magicians to establish their            
authority--,derived from a   knowledge  
of the phenomena of ,nature--,from the  
influence of narcotic   drugs upon the  
victims of their delusion--,from every  
branch of                               
science--,acoustics--,hydrostatics--,mec
hanics--,optics--,m4 ,salverte's   work 
on the occult sciences--,object of the  
following letters4        ,,my ,,dear   
,,sir ,,walter1    ,as it was at your   
suggestion that ,i undertook to draw up 
a popular  account of those prodigies of
 the material world which have received 
the appellation of ,natural ,magic1 ,i  
have availed myself of the  privilege of

 introducing it under the shelter of    
your name4 ,although  ,i cannot hope to 
produce a volume at all approaching in  
interest  to that which you have        
contributed to the ,family ,library1 yet
 the  popular character of some of the  
topics which belong to this branch of   
,demonology may atone for the defects of
 the following ,letters2 and ,i  shall  
deem it no slight honour if they shall  
be considered as forming  an appropriate
 supplement to your valuable work4      
,the subject of ,natural ,magic is one  
of great extent as well as of  deep     
interest4 ,in its widest range1 it      
embraces the history of the  governments
 and the superstitions of ancient       
times1--of the means by  which they     
maintained their influence over the     
human mind1--of the  assistance which   
they derived from the arts and the      
sciences1 and from  a knowledge of the  
powers and phenomena of nature4 ,when   
the tyrants  of antiquity were unable or
 unwilling to found their sovereignty on

  the affections and interests of their 
people1 they sought to entrench         
themselves in the strongholds of        
supernatural influence1 and to rule     
with the delegated authority of ,heaven4
 ,the prince1 the priest1 and the  sage1
 were leagued in a dark conspiracy to   
deceive and enslave their  species2 and 
man1 who refused his submission to a    
being like himself1  became the obedient
 slave of a spiritual despotism1 and    
willingly bound  himself in chains when 
they seemed to have been forged by the  
gods4    ,this system of imposture was  
greatly favoured by the ignorance of    
these  early ages4 ,the human mind is at
 all times fond of the marvellous1  and 
the credulity of the individual may be  
often measured by his own  attachment to
 the truth4 ,when knowledge was the     
property of only one  caste1 it was by  
no means difficult to employ it in the  
subjugation  of the great mass of       
society4 ,an acquaintance with the      
motions of the  heavenly bodies1 and the

 variations in the state of the         
atmosphere1  enabled its possessor to   
predict astronomical and meteorological 
phenomena with a frequency and an       
accuracy which could not fail to  invest
 him with a divine character4 ,the power
 of bringing down fire  from the        
heavens1 even at times when the electric
 influence was  itself in a state of    
repose1 could be regarded only as a gift
 from  heaven4 ,the power of rendering  
the human body insensible to fire was   
an irresistible instrument of imposture2
 and in the combinations of  chemistry1 
and the influence of drugs and soporific
 embrocations on the  human frame1 the  
ancient magicians found their most      
available resources4    ,the secret use 
which was thus made of scientific       
discoveries and  of remarkable          
inventions1 has no doubt prevented many 
of them from  reaching the present      
times2 but though we are very ill       
informed  respecting the progress of the
 ancients in various departments of the 

physical sciences1 yet we have          
sufficient evidence that almost every   
branch of knowledge had contributed its 
wonders to the magician's  budget1 and  
we may even obtain some insight into the
 scientific  acquirements of former     
ages1 by a diligent study of their      
fables and  their miracles4    ,the     
science of ,acoustics furnished the     
ancient sorcerers with some of  their   
best deceptions4 ,the imitation of      
thunder in their subterranean  temples  
could not fail to indicate the presence 
of a supernatural  agent4 ,the golden   
virgins whose ravishing voices resounded
 through the  temple of ,delphos2--the  
stone from the river ,pactolus1 whose   
trumpet  notes scared the robber from   
the treasure which it guarded2--the     
speaking head which uttered its oracular
 responses at ,lesbos2 and the  vocal   
statue of ,memnon1 which began at the   
break of day to accost the  rising      
sun1--were all deceptions derived from  
science1 and from a  diligent           

observation of the phenomena of nature4 
,the principles of ,hydrostatics were   
equally available in the work of        
deception4 ,the marvellous fountain     
which ,pliny describes in the island  of
 ,andros as discharging wine for seven  
days1 and water during the rest  of the 
year2--the spring of oil which broke out
 in ,rome to welcome the  return of     
,augustus from the ,sicilian war1--the  
three empty urns which  filled          
themselves with wine at the annual feast
 of ,bacchus in the city  of ,elis1--the
 glass tomb of ,belus which was full of 
oil1 and which when  once emptied by    
,xerxes could not again be filled1--the 
weeping-statues1  and the perpetual     
lamps of the ancients1--were all the    
obvious effects  of the equilibrium and 
pressure of fluids4    ,although we have
 no direct evidence that the            
philosophers of antiquity  were skilled 
in ,mechanics1 yet there are indications
 of their  knowledge by no means        
equivocal in the erection of the        

,egyptian  obelisks1 and in the         
transportation of huge masses of stone1 
and their  subsequent elevation to great
 heights in their temples4 ,the powers  
which they employed1 and the mechanism  
by which they operated1 have  been      
studiously concealed1 but their         
existence may be inferred from  results 
otherwise inexplicable2 and the         
inference derives additional            
confirmation from the mechanical        
arrangements which seemed to have       
formed a part of their religious        
impostures4 ,when1 in some of the       
infamous mysteries of ancient ,rome1 the
 unfortunate victims were  carried off  
by the gods1 there is reason to believe 
that they were  hurried away by the     
power of machinery2 and when            
,apollonius1 conducted  by the ,indian  
sages to the temple of their god1 felt  
the earth rising  and falling beneath   
his feet1 like the agitated sea1 he was 
no doubt  placed upon a moving floor    
capable of imitating the heavings of the

  waves4 ,the rapid descent of those who
 consulted the oracle in the  cave of   
,trophonius1--the moving tripods which  
,apollonius saw in the  ,indian         
temples1--the walking statues at        
,antium1 and in the temple of           
,hierapolis1--and the wooden pigeon of  
,archytas1 are specimens of the         
mechanical resources of the ancient     
magic4    ,but of all the sciences      
,optics is the most fertile in          
marvellous  expedients4 ,the power of   
bringing the remotest objects within the
 very  grasp of the observer1 and of    
swelling into gigantic magnitude the    
almost invisible bodies of the material 
world1 never fails to inspire  with     
astonishment even those who understand  
the means by which these  prodigies are 
accomplished4 ,the ancients1 indeed1    
were not acquainted  with those         
combinations of lenses and mirrors which
 constitute the  telescope and the      
microscope1 but they must have been     
familiar with  the property of lenses   

and mirrors to form erect and inverted  
images  of objects4 ,there is reason to 
think that they employed them to effect 
the apparition of their gods2 and in    
some of the descriptions of the  optical
 displays which hallowed their ancient  
temples1 we recognize  all the          
transformations of the modern           
phantasmagoria4    ,it would be an      
interesting pursuit to embody the       
information which  history supplies     
respecting the fables and incantations  
of the ancient  superstitions1 and to   
show how far they can be explained by   
the  scientific knowledge which then    
prevailed4 ,this task has1 to a certain 
extent1 been performed by ,m4 ,eusebe   
,salverte1 in a work on the occult      
sciences which has recently appeared2   
but notwithstanding the ingenuity  and  
learning which it displays1 the         
individual facts are too scanty to      
support the speculations of the author1 
and the descriptions are too  meagre to 
satisfy the curiosity of the reader4#a  

#a ,we must caution the young reader    
against some of the views given   in ,m4
 ,salverte's work4 ,in his anxiety to   
account for everything   miraculous by  
natural causes1 he has ascribed to the  
same origin some   of these events in   
sacred history which ,christians cannot 
but regard   as the result of divine    
agency4    ,in the following letters ,i 
propose to take a wider range1 and to   
enter  into more minute and popular     
details4 ,the principal phenomena of    
nature1 and the leading combinations of 
arts1 which bear the impress of  a      
supernatural character1 will pass under 
our review1 and our attention  will be  
particularly called to those singular   
illusions of sense1 by  which the most  
perfect organs either cease to perform  
their functions1  or perform them       
faithlessly2 and where the efforts and  
the creations of  the mind predominate  
over the direct perceptions of external 
nature4    ,in executing this plan1 the 
task of selection is rendered extremely 

difficult by the superabundance of      
materials1 as well as from the  variety 
of judgments for which these materials  
must be prepared4 ,modern  science may  
be regarded as one vast miracle1 whether
 we view it in  relation to the         
,almighty ,being by whom its objects and
 its laws were  formed1 or to the feeble
 intellect of man1 by which its depths  
have  been sounded1 and its mysteries   
explored2 and if the philosopher who is 
familiarized with its wonders1 and who  
has studied them as necessary  results  
of general laws1 never ceases to admire 
and adore their ,author1  how great     
should be their effect upon less gifted 
minds1 who must ever  view them in the  
light of inexplicable prodigies6--,man  
has in all ages  sought for a sign from 
heaven1 and yet he has been habitually  
blind to  the millions of wonders with  
which he is surrounded4 ,if the         
following  pages should contribute to   
abate this deplorable indifference to   
all  that is grand and sublime in the   

universe1 and if they should inspire    
the reader with a portion of that       
enthusiasm of love and gratitude  which 
can alone prepare the mind for its final
 triumph1 the labours of  the author    
will not have been wholly fruitless4    
,,letter ,,ii4     ,the eye the most    
important of our organs--,popular       
description   of it--,the eye is the    
most fertile source of mental           
illusions--,disappearance of objects    
when their images fall   upon the base  
of the optic nerve--,disappearance of   
objects   when seen                     
obliquely--,deceptions arising from     
viewing objects   in a faint            
light--,luminous figures created by     
pressure on the   eye1 either from      
external causes or from the fulness of  
the   blood-vessels--,ocular spectra or 
accidental colours--,remarkable         
effects produced by intense             
light--,influence of the imagination    
in viewing these spectra--,remarkable   
illusion produced by this   affection of

 the eye--,duration of impressions of   
light on the                            
eye--,thaumatrope--,improvements upon it
 suggested--,disappearance of   halves  
of objects or of one of two             
persons--,insensibility of the eye   to 
particular colours--,remarkable optical 
illusion described4      ,of all the    
organs by which we acquire a knowledge  
of external nature1  the eye is the most
 remarkable and the most important4 ,by 
our other  senses the information we    
obtain is comparatively limited4 ,the   
touch  and the taste extend no farther  
than the surface of our own bodies4     
,the sense of smell is exercised within 
a very narrow sphere1 and that  of      
recognizing sounds is limited to the    
distance at which we hear the  bursting 
of a meteor and the crash of a          
thunderbolt4 ,but the eye enjoys  a     
boundless range of observation4 ,it     
takes cognizance not only of  other     
worlds belonging to the solar system1   
but of other systems of  worlds         

infinitely removed into the immensity of
 space2 and when aided  by the          
telescope1 the invention of human       
wisdom1 it is able to discover  the     
forms1 the phenomena1 and the movements 
of bodies whose distance is  as         
inexpressible in language as it is      
inconceivable in thought4    ,while the 
human eye has been admired by ordinary  
observers for the  beauty of its form1  
the power of its movements1 and the     
variety of its  expression1 it has      
excited the wonder of philosophers by   
the exquisite  mechanism of its         
interior1 and its singular adaptation to
 the variety  of purposes which it has  
to serve4 ,the eyeball is nearly        
globular1  and is about an inch in      
diameter4 ,it is formed externally by a 
tough  opaque membrane called the       
sclerotic coat1 which forms the white of
  the eye1 with the exception of a small
 circular portion in front called  the  
cornea4 ,this portion is perfectly      
transparent1 and so tough in  its nature

 as to afford a powerful resistance to  
external injury4  ,immediately within   
the cornea1 and in contact with it1 is  
the aqueous  humour1 a clear fluid1     
which occupies only a small part of the 
front  of the eye4 ,within this humour  
is the iris1 a circular membrane1 with  
a hole in its centre called the pupil4  
,the colour of the eye resides  in this 
membrane1 which has the curious property
 of contracting and  expanding so as to 
diminish or enlarge the pupil1--an      
effect which  human ingenuity has not   
been able even to imitate4 ,behind the  
iris is  suspended the crystalline lens1
 in a fine transparent capsule or bag   
of the same form with itself4 ,it is    
then succeeded by the vitreous  humour1 
which resembles the transparent white of
 an egg1 and fills  up the rest of the  
eye4 ,behind the vitreous humour1 there 
is spread  out on the inside of the     
eyeball a fine delicate membrane1 called
 the  retina1 which is an expansion of  
the optic nerve1 entering the back  of  

the eye and communicating with the      
brain4    ,a perspective view and       
horizontal section of the left eye1     
shown in the  annexed figure1 will      
convey a popular idea of its structure4 
,it is1  as it were1 a small camera     
obscura1 by means of which the pictures 
of  external objects are painted on the 
retina1 and1 in a way of which we  are  
ignorant1 it conveys the impression of  
them to the brain4    ,illustration3    
,fig4 #a4    ,this wonderful organ may  
be considered as the sentinel which     
guards the  pass between the worlds of  
matter and of spirit1 and through which 
all  their communications are           
interchanged4 ,the optic nerve is the   
channel  by which the mind peruses the  
hand-writing of ,nature on the retina1  
and through which it transfers to that  
material tablet its decisions  and its  
creations4 ,the eye is consequently the 
principal seat of the  supernatural4    
,when the indications of the marvellous 
are addressed to  us through the ear1   

the mind may be startled without being  
deceived1  and reason may succeed in    
suggesting some probable source of the  
illusion by which we have been alarmed3 
but when the eye in solitude  sees      
before it the forms of life1 fresh in   
their colours and vivid in  their       
outline2 when distant or departed       
friends are suddenly presented  to its  
view2 when visible bodies disappear and 
reappear without any  intelligible      
cause2 and when it beholds objects1     
whether real or  imaginary1 for whose   
presence no cause can be assigned1 the  
conviction  of supernatural agency      
becomes1 under ordinary circumstances1  
unavoidable4    ,hence it is not only an
 amusing but a useful occupation to     
acquire a  knowledge of those causes    
which are capable of producing so       
strange a  belief1 whether it arises    
from the delusions which the mind       
practises  upon itself1 or from the     
dexterity and science of others4 ,i     
shall  therefore proceed to explain     

those illusions which have their origin 
in  the eye1 whether they are general1  
or only occasionally exhibited in       
particular persons1 and under particular
 circumstances4    ,there are few       
persons aware that when they look with  
one eye1 there is  some particular      
object before them to which they are    
absolutely blind4  ,if we look with the 
right eye1 this point is always about   
#ae to the  right of the object which we
 are viewing1 or to the right of the    
axis  of the eye or the point of most   
distinct vision4 ,if we look with the   
left eye1 the point is as far to the    
left4 ,in order to be convinced  of this
 curious fact1 which was discovered by  
,m4 ,mariotte1 place two  coloured      
wafers upon a sheet of white paper at   
the distance of three  inches1 and look 
at the left-hand wafer with the right   
eye at the  distance of about #aa or #ab
 inches1 taking care to keep the eye    
straight  above the wafer1 and the line 
which joins the eyes parallel to the    

line  which joins the wafers4 ,when this
 is done1 and the left eye closed1 the  
right-hand wafer will no longer be      
visible4 ,the same effect will be       
produced if we close the right eye and  
look with the left eye at the           
right-hand wafer4 ,when we examine the  
retina to discover to what part  of it  
this insensibility to light belongs1 we 
find that the image of  the invisible   
wafer has fallen on the base of the     
optic nerve1 or the  place where this   
nerve enters the eye and expands itself 
to form the  retina4 ,this point is     
shown in the preceding figure by a      
convexity at  the place where the nerve 
enters the eye4    ,but though light of 
ordinary intensity makes no impression  
upon this  part of the eye1 a very      
strong light does1 and even when we use 
candles  or highly luminous bodies in   
place of wafers1 the body does not      
wholly  disappear1 but leaves behind a  
faint cloudy light1 without1 however1   
giving anything like an image of the    

object from which the light  proceeds4  
,when the objects are white wafers upon 
a black ground1 the white  wafer        
absolutely disappears1 and the space    
which it covers appears to  be          
completely black2 and as the light which
 illuminates a landscape  is not much   
different from that of a white wafer1 we
 should expect1  whether we use one or  
both eyes1#b to see a black or a dark   
spot  upon every landscape1 within #ae  
of the point which most particularly    
attracts our notice4 ,the ,divine       
,artificer1 however1 has not left his   
work thus imperfect4 ,though the base of
 the optic nerve is insensible  to light
 that falls directly upon it1 yet it has
 been made susceptible  of receiving    
luminous impressions from the parts     
which surround it2 and  the consequence 
of this is1 that when the wafer         
disappears1 the spot  which is occupied1
 in place of being black1 has always the
 same colour  as the ground upon which  
the wafer is laid1 being white when the 

wafer  is placed upon a white ground1   
and red when it is placed upon a red    
ground4 ,this curious effect may be     
rudely illustrated by comparing the     
retina to a sheet of blotting-paper1 and
 the base of the optic nerve to  a      
circular portion of it covered with a   
piece of sponge4 ,if a shower  falls    
upon the paper1 the protected part will 
not be wetted by the rain  which falls  
upon the sponge that covers it1 but in a
 few seconds it  will be as effectually 
wetted by the moisture which it absorbs 
from the  wet paper with which it is    
surrounded4 ,in like manner the         
insensible  spot on the retina is       
stimulated by a borrowed light1 and the 
apparent  defect is so completely       
removed1 that its existence can be      
determined  only by the experiment      
already described4     #b ,when both    
eyes are open1 the object whose image   
falls upon the   insensible spot of the 
one eye is seen by the other1 so that1  
though   it is not invisible1 yet it    

will only be half as luminous and1      
therefore two dark spots ought to be    
seen4    ,of the same character1 but far
 more general in its effects1 and       
important in its consequences1 is       
another illusion of the eye which       
presented itself to me several years    
ago4 ,when the eye is steadily  occupied
 in viewing any particular object1 or   
when it takes a fixed  direction while  
the mind is occupied with any engrossing
 topic of  speculation or of grief1 it  
suddenly loses sight of1 or becomes     
blind  to1 objects seen indirectly1 or  
upon which it is not fully directed4    
,this takes place whether we use one or 
both eyes1 and the object which         
disappears will reappear without any    
change in the position of the  eye1     
while other objects will vanish and     
revive in succession without  any       
apparent cause4 ,if a sportsman1 for    
example1 is watching with  intense      
interest the motions of one of his dogs1
 his companion1 though  seen with       

perfect clearness by indirect vision1   
will vanish1 and the  light of the heath
 or of the sky will close in upon the   
spot which he  occupied4    ,in order to
 witness this illusion1 put a little bit
 of white paper on  a green cloth1 and1 
within three or four inches of it1 place
 a narrow  strip of white paper4 ,at the
 distance of twelve or eighteen inches1 
fix  one eye steadily upon the little   
bit of white paper1 and in a short  time
 a part or even the whole of the strip  
of paper will vanish as if  it had been 
removed from the green cloth4 ,it will  
again reappear1 and  again vanish1 the  
effect depending greatly on the         
steadiness with which  the eye is kept  
fixed4 ,this illusion takes place when  
both the eyes are  open1 though it is   
easier to observe it when one of them is
 closed4 ,the  same thing happens when  
the object is luminous4 ,when a candle  
is thus  seen by indirect vision1 it    
never wholly disappears1 but it spreads 
itself out into a cloudy mass1 the      

centre of which is blue1 encircled  with
 a bright ring of yellow light4    ,this
 inability of the eye to preserve a     
sustained vision of objects  seen       
obliquely1 is curiously compensated by  
the greater sensibility of  those parts 
of the eye that have this defect4 ,the  
eye has the power  of seeing objects    
with perfect distinctness only when it  
is directed  straight upon them2 that   
is1 all objects seen indirectly are seen
  indistinctly3 but it is a curious     
circumstance1 that when we wish to      
obtain a sight of a very faint star1    
such as one of the satellites of        
,saturn1 we can see it most distinctly  
by looking away from it1 and  when the  
eye is turned full upon it it           
immediately disappears4    ,effects     
still more remarkable are produced in   
the eye when it views  objects that are 
difficult to be seen from the small     
degree of light  with which they happen 
to be illuminated4 ,the imperfect view  
which we  obtain of such objects forces 

us to fix the eye more steadily upon    
them2 but the more exertion we make to  
ascertain what they are1 the  greater   
difficulties do we encounter to         
accomplish our object4 ,the  eye is     
actually thrown into a state of the most
 painful agitation1  the object will    
swell and contract1 and partly          
disappear1 and it will  again become    
visible when the eye has recovered from 
the delirium into  which it has been    
thrown4 ,this phenomenon may be most    
distinctly seen  when the objects in a  
room are illuminated with the feeble    
gleam of a  fire almost extinguished2   
but it may be observed in daylight by   
the  sportsman when he endeavours to    
mark upon the monotonous heath the      
particular spot where moor-game has     
alighted4 ,availing himself of  the     
slightest difference of tint in the     
adjacent heath1 he keeps his  eye       
steadily fixed on it as he advances1 but
 whenever the contrast of  illumination 
is feeble1 he will invariably lose sight

 of his mark1  and if the retina is     
capable of taking it up1 it is only to  
lose it a  second time4    ,this        
illusion is likely to be most           
efficacious in the dark1 when there  is 
just sufficient light to render white   
objects faintly visible1 and  to persons
 who are either timid or credulous must 
prove a frequent  source of alarm4 ,its 
influence1 too1 is greatly aided by     
another  condition of the eye1 into     
which it is thrown during partial       
darkness4  ,the pupil expands nearly to 
the whole width of the iris1 in order to
  collect the feeble light which        
prevails2 but it is demonstrable that   
in this state the eye cannot accommodate
 itself to see near objects  distinctly1
 so that the forms of persons and things
 actually become  more shadowy and      
confused when they come within the very 
distance at  which we count upon        
obtaining the best view of them4 ,these 
affections  of the eye are1 we are      
persuaded1 very frequent causes of a    

particular  class of apparitions which  
are seen at night by the young and the  
ignorant4 ,the spectres which are       
conjured up are always white1  because  
no other colour can be seen1 and they   
are either formed out of  inanimate     
objects which reflect more light than   
others around them1  or of animals or   
human beings whose colour or change of  
place renders  them more visible in the 
dark4 ,when the eye dimly descries an   
inanimate  object whose different parts 
reflect different degrees of light1 its 
brighter parts may enable the spectator 
to keep up a continued view  of it2 but 
the disappearance and reappearance of   
its fainter parts1  and the change of   
shape which ensues1 will necessarily    
give it the  semblance of a living form1
 and if it occupies a position which is 
unapproachable1 and where animate       
objects cannot find their way1 the  mind
 will soon transfer to it a supernatural
 existence4 ,in like manner  a human    
figure shadowed forth in a feeble       

twilight may undergo similar  changes1  
and after being distinctly seen while it
 is in a situation  favourable for      
receiving and reflecting light1 it may  
suddenly  disappear in a position fully 
before1 and within the reach of1 the    
observer's eye2 and if this evanescence 
takes place in a path or road  where    
there was no side-way by which the      
figure could escape1 it is  not easy for
 an ordinary mind to efface the         
impression which it cannot  fail to     
receive4 ,under such circumstances we   
never think of distrusting  an organ    
which we have never found to deceive us2
 and the truth of  the maxim that       
8seeing is believing0 is too universally
 admitted1 and  too deeply rooted in our
 nature1 to admit on any occasion of a  
single  exception4    ,in these         
observations we have supposed that the  
spectator bears along  with him no fears
 or prejudices1 and is a faithful       
interpreter of the  phenomena presented 
to his senses2 but if he is himself a   

believer  in apparitions1 and unwilling 
to receive an ocular demonstration of   
their reality1 it is not difficult to   
conceive the picture which will  be     
drawn when external objects are         
distorted and caricatured by the        
imperfect indications of his senses1 and
 coloured with all the vivid  hues of   
the imagination4    ,another class of   
ocular deceptions have their origin in a
 property of  the eye which has been    
very imperfectly examined4 ,the fine    
nervous  fabric which constitutes the   
retina1 and which extends to the brain1 
has the singular property of being      
phosphorescent by pressure4 ,when  we   
press the eyeball outwards by applying  
the point of the finger  between it and 
the nose1 a circle of light will be     
seen1 which ,sir  ,isaac ,newton        
describes as 8a circle of colours like  
those in the  feather of a peacock's    
tail40 ,he adds1 that 8if the eye and   
the  figure remain quiet1 these colours 
vanish in a second of time2 but  if the 

finger be moved with a quavering motion1
 they appear again40  ,in the numerous  
observations which ,i have made on these
 luminous  circles1 ,i have never been  
able to observe any colour but white1   
with  the exception of a general red    
tinge which is seen when the eyelids    
are closed1 and which is produced by the
 light which passes through  them4 ,the 
luminous circles1 too1 always continue  
while the pressure  is applied1 and they
 may be produced as readily after the   
eye has  been long in darkness as when  
it has been recently exposed to light4  
,when the pressure is very gently       
applied1 so as to compress the fine     
pulpy substance of the retina1 light is 
immediately created when the  eye is in 
total darkness2 and when in this state  
light is allowed to  fall upon it1 the  
part compressed is more sensible to     
light than any  other part1 and         
consequently appears more luminous4 ,if 
we increase the  pressure1 the eyeball1 
being filled with incompressible fluids1

 will  protrude all round the point of  
pressure1 and consequently the retina   
at the protruded part will be compressed
 by the outward pressure  of the        
contained fluid1 while the retina on    
each side1 namely1 under  the point of  
pressure and beyond the protruded part1 
will be drawn  towards the protruded    
part or dilated4 ,hence the part under  
the  finger which was originally        
compressed is now dilated1 the adjacent 
parts compressed1 and the more remote   
parts immediately without this  dilated 
also4 ,now we have observed1 that when  
the eye is1 under  these circumstances1 
exposed to light1 there is a bright     
luminous  circle shading off externally 
and internally into total darkness4  ,we
 are led1 therefore1 to the important   
conclusions1 that when the  retina is   
compressed in total darkness it gives   
out light2 that when  it is compressed  
when exposed to light1 its sensibility  
to light is  increased2 and that when it
 is dilated under exposure to light1 it 

becomes absolutely blind1 or insensible 
to all luminous impressions4    ,when   
the body is in a state of perfect       
health1 this phosphorescence  of the eye
 shows itself on many occasions4 ,when  
the eye or the head  receives a sudden  
blow1 a bright flash of light shoots    
from the  eyeball4 ,in the act of       
sneezing1 gleams of light are emitted   
from each  eye both during the          
inhalation of the air1 and during its   
subsequent  protrusion1 and in blowing  
air violently through the nostrils1 two 
patches of light appear above the axis  
of the eye and in front of it1  while   
other two luminous spots unite into one1
 and appear as it were  about the point 
of the nose when the eyes are directed  
to it4 ,when  we turn the eyeball by the
 action of its own muscles1 the retina  
is  affected at the place where the     
muscles are inserted1 and there may  be 
seen opposite each eye1 and towards the 
nose1 two semicircles of  light1 and    
other two extremely faint towards the   

temples4 ,at particular  times1 when the
 retina is more phosphorescent than at  
others1 these  semicircles are expanded 
into complete circles of light4    ,in a
 state of indisposition1 the            
phosphorescence of the retina  appears  
in new and more alarming forms4 ,when   
the stomach is under a  temporary       
derangement accompanied with headache1  
the pressure of the  blood-vessels upon 
the retina shows itself1 in total       
darkness1 by a  faint blue light        
floating before the eye1 varying in its 
shape1 and  passing away at one side4   
,this blue light increases in intensity1
  becomes green and then yellow1 and    
sometimes rises to red1 all  these      
colours being frequently seen at once1  
or the mass of light  shades off into   
darkness4 ,when we consider the variety 
of distinct  forms which in a state of  
perfect health the imagination can      
conjure  up when looking into a burning 
fire1 or upon an irregularly shaded     
surface1#c it is easy to conceive how   

the masses of coloured light  which     
float before the eye may be moulded by  
the same power into those  fantastic and
 natural shapes1 which so often haunt   
the couch of the  invalid1 even when the
 mind retains its energy1 and is        
conscious of the  illusion under which  
it labours4 ,in other cases1 temporary  
blindness  is produced by pressure upon 
the optic nerve1 or upon the retina2 and
  under the excitation of fever or      
delirium1 when the physical cause  which
 produces spectral forms is at its      
height1 there is superadded a  powerful 
influence of the mind1 which imparts a  
new character to the  phantasms of the  
senses4     #c ,a very curious example  
of the influence of the imagination in  
creating distinct forms out of an       
irregularly shaded surface1 is          
mentioned in the life of ,peter ,heaman1
 a ,swede1 who was executed for   piracy
 and murder at ,leith in #ahbb4 ,we give
 it in his own words3--     8,one       
remarkable thing was1 one day as we     

mended a sail1 it being a   very thin   
one1 after laying it upon deck in folds1
 ,i took the tar   brush and tarred it  
over in the places which ,i thought     
needed to be   strengthened4 ,but when  
we hoisted it up1 ,i was astonished to  
see that   the tar ,i had put upon it   
represented a gallows and a man under it
   without a head4 ,the head was lying  
beside him4 ,he was complete1 body1     
thighs1 legs1 arms1 and in every shape  
like a man4 ,now1 ,i oftentimes   made  
remarks upon it1 and repeated them to   
the others4 ,i always said   to them    
all1 ,you may depend upon it that       
something will happen4 ,i   afterwards  
took down the sail on a calm day1 and   
sewed a piece of   canvas over the      
figure to cover it1 for ,i could not    
bear to have it   always before my      
eyes40    ,in order to complete the     
history of the illusions which originate
 in  the eye1 it will be necessary to   
give some account of the phenomena      
called ocular spectra1 or accidental    

colours4 ,if we cut a figure  out of red
 paper1 and1 placing it on a sheet of   
white paper1 view it  steadily for some 
seconds with one or both eyes fixed on a
 particular  part of it1 we shall       
observe the red colour to become less   
brilliant4  ,if we then turn the eye    
from the red figure upon the white      
paper1  we shall see a distinct green   
figure1 which is the spectrum1 or       
accidental colour of the red figure4    
,with differently coloured  figures we  
shall observe differently coloured      
spectra1 as in the  following table3--  
,,colour ,,of ,,the                     
,,colour ,,of ,,the    ,,original       
,,figures4          ,,spectral          
,,figures4        ,red1                 
,bluish-green4      ,orange1            
,blue4      ,yellow1                    
,indigo4      ,green1                   
,reddish-violet4      ,blue1            
,orange-red4      ,indigo1              
,orange-yellow4      ,violet1           
,yellow4      ,white1                   

,black4      ,black1                    
,white4    ,the two last of these       
experiments1 viz41 white and black      
figures1 may  be satisfactorily made by 
using a white medallion on a dark       
ground1 and  a black profile figure4    
,the spectrum of the former will be     
found to be  black1 and that of the     
latter white4    ,these ocular spectra  
often show themselves without any effort
 on  our part1 and even without our     
knowledge4 ,in a highly painted room1   
illuminated by the sun1 those parts of  
the furniture on which the sun  does not
 directly fall have always the opposite 
or accidental colour4  ,if the sun      
shines through a chink in a red         
window-curtain1 its light  will appear  
green1 varying as in the above table1   
with the colour of  the curtain2 and if 
we look at the image of a candle1       
reflected from  the water in a blue     
finger-glass1 it will appear yellow4    
,whenever1  in short1 the eye is        
affected with one prevailing colour1 it 

sees at  the same time the spectral or  
accidental colour1 just as when a       
musical  string is vibrating1 the ear   
hears at the same time its fundamental  
and  its harmonic sounds4    ,if the    
prevailing light is white and very      
strong1 the spectra which  it produces  
are no longer black1 but of various     
colours in succession4  ,if we look at  
the sun1 for example1 when near the     
horizon1 or when  reflected from glass  
or water so as to moderate its          
brilliancy1 and  keep the eye upon it   
steadily for a few seconds1 we shall    
see1 even for  hours afterwards1 and    
whether the eyes are open or shut1 a    
spectrum  of the sun varying in its     
colours4 ,at first1 with the eye open1  
it is  brownish-red with a sky-blue     
border1 and when the eye is shut1  it is
 green with a red border4 ,the red      
becomes more brilliant1  and the blue   
more vivid1 till the impression is      
gradually worn off2  but even when they 
become very faint1 they may be revived  

by a gentle  pressure on the eyeball4   
,some eyes are more susceptible than    
others of these spectral  impressions1  
and ,mr4 ,boyle mentions an individual  
who continued for  years to see the     
spectre of the sun when he looked upon  
bright objects4  ,this fact appeared to 
,locke so interesting and inexplicable1 
that he  consulted ,sir ,isaac ,newton  
respecting its cause1 and drew from him 
the  following interesting account of a 
similar effect upon himself3--8,the     
observation you mention in ,mr4 ,boyle's
 book of colours1 ,i once made  upon    
myself with the hazard of my eyes4 ,the 
manner was this3 ,i looked  a very      
little while upon the sun in the        
looking-glass with my right  eye1 and   
then turned my eyes into a dark corner  
of my chamber1 and  winked1 to observe  
the impression made1 and the circles of 
colours  which encompassed it1 and how  
they decayed by degrees1 and at last    
vanished4 ,this ,i repeated a second and
 a third time4 ,at the third time1  when

 the phantasm of light and colours about
 it were almost vanished1  intending my 
fancy upon them to see their last       
appearance1 ,i found1 to  my amazement1 
that they began to return1 and by little
 and little to  become as lively and    
vivid as when ,i had newly looked upon  
the sun4  ,but when ,i ceased to intend 
my face upon them1 they vanished again4 
,after this ,i found that as often as ,i
 went into the dark1 and intended  my   
mind upon them1 as when a man looks     
earnestly to see anything which  is     
difficult to be seen1 ,i could make the 
phantasm return without  looking any    
more upon the sun2 and the oftener ,i   
made it return1 the  more easily ,i     
could make it return again4 ,and at     
length1 by repeating  this without      
looking any more upon the sun1 ,i made  
such an impression  on my eye1 that1 if 
,i looked upon the clouds1 or a book1 or
 any bright  object1 ,i saw upon it a   
round bright spot of light like the sun1
 and1  which is still stranger1 though  

,i looked upon the sun with my right eye
  only1 and not with my left1 yet my    
fancy began to make an impression  upon 
my left eye as well as upon my right4   
,for if ,i shut my right eye1  and      
looked upon a book or the clouds with my
 left eye1 ,i could see the  spectrum of
 the sun almost as plain as with my     
right eye1 if ,i did  but intend my     
fancy a little while upon it3 for at    
first1 if ,i shut  my right eye1 and    
looked with my left1 the spectrum of the
 sun did  not appear till ,i intended my
 fancy upon it2 but by repeating1 this  
appeared every time more easily4 ,and   
now in a few hours' time ,i had  brought
 my eyes to such a pass1 that ,i could  
look upon no bright object  with either 
eye but ,i saw the sun before me1 so    
that ,i durst neither  write nor read2  
but to recover the use of my eyes1 shut 
myself up in  my chamber1 made dark1 for
 three days together1 and used all means
  in my power to direct my imagination  
from the sun4 ,for if ,i thought  upon  

him1 ,i presently saw his picture1      
though ,i was in the dark4 ,but  by     
keeping in the dark2 and employing my   
mind about other things1 ,i  began1 in  
three or four days1 to have more use of 
my eyes again2 and  by forbearing to    
look upon bright objects1 recovered them
 pretty well2  though not so well but   
that1 for some months after1 the        
spectrums  of the sun began to return as
 often as ,i began to meditate upon the 
phenomena1 even though ,i lay in bed at 
midnight with my curtains drawn4  ,but  
now ,i have been well for many years1   
though ,i am apt to think1 if  ,i durst 
venture my eyes1 ,i could still make the
 phantasm return by  the power of my    
fancy4 ,this story ,i tell you1 to let  
you understand1  that in the observation
 related by ,mr4 ,boyle1 the man's fancy
 probably  concurred with the impression
 made by the sun's light to produce that
  phantasm of the sun which he          
constantly saw in bright objects40#d    
#d ,see the ,edinburgh ,encyclopdia1    

,art4 ,,accidental ,,colours4    ,i am  
not aware of any effects that had the   
character of supernatural  having been  
actually produced by the causes above   
described2 but it  is obvious1 that if a
 living figure had been projected       
against the  strong light which         
imprinted these durable spectra of the  
sun1 which  might really happen when the
 solar rays are reflected from water1   
and  diffused by its ruffled surface1   
this figure would have necessarily      
accompanied all the luminous spectres   
which the fancy created4 ,even in       
ordinary lights1 strange appearances may
 be produced by even transient          
impressions2 and if ,i am not greatly   
mistaken1 the case which ,i am  about to
 mention is not only one which may      
occur1 but which actually  happened4 ,a 
figure dressed in black1 and mounted    
upon a white  horse1 was riding along1  
exposed to the bright rays of the sun1  
which1 through a small opening in the   
clouds1 was throwing its light  only    

upon that part of the landscape4 ,the   
black figure was projected  against a   
white cloud1 and the white horse shone  
with particular  brilliancy by its      
contrast with the dark soil against     
which it was  seen4 ,a person interested
 in the arrival of such a stranger had  
been  for some time following his       
movements with intense anxiety1 but1    
upon  his disappearance behind a wood1  
was surprised to observe the spectre  of
 the mounted stranger in the form of a  
white rider upon a black  steed1 and    
this spectre was seen for some time in  
the sky1 or upon  any pale ground to    
which the eye was directed4 ,such an    
occurrence1  especially if accompanied  
with a suitable combination of events1  
might1  even in modern times1 have      
formed a chapter in the history of the  
marvellous4    ,it is a curious         
circumstance1 that when the image of an 
object is  impressed upon the retina    
only for a few moments1 the picture     
which  is left is exactly of the same   

colour with the object4 ,if we look1    
for example1 at a window at some        
distance from the eye1 and then         
transfer the eye quickly to the wall1 we
 shall see it distinctly1 but           
momentarily1 with light panes and dark  
bars2 but in a space of  time           
incalculably short1 this picture is     
succeeded by the spectral  impression of
 the window1 which will consist of black
 panes and  white bars4 ,the similar    
spectrum1 or that of the same colour as 
the  object1 is finely seen in the      
experiment of forming luminous circles  
by  whirling round a burning stick1 in  
which case the circles are always  red4 
,in virtue of this property of the eye1 
an object may be seen in  many places at
 once2 and we may even exhibit at the   
same instant  the two opposite sides of 
the same object1 or two pictures painted
  on the opposite sides of a piece of   
card4 ,it was found by a ,french        
philosopher1 ,m4 ,d',arcet1 that the    
impression of light continued on the    

retina about the eighth part of a second
 after the luminous body was  withdrawn1
 and upon this principle ,dr4 ,paris has
 constructed the pretty  little         
instrument called the ,thaumatrope1 or  
the ,wonder-turner4 ,it  consists of a  
number of circular pieces of card1 about
 two or three  inches broad1 which may  
be twirled round with great velocity by 
the  application of the fore-finger and 
thumb of each hand to pieces of silk    
string attached to opposite points of   
their circumference4 ,on each  side of  
the circular piece of card is painted   
part of a picture1 or  a part of a      
figure1 in such a manner that the two   
parts would form a  group or a whole    
figure1 if we could see both sides at   
once4 ,harlequin1  for example1 is      
painted on one side1 and ,columbine on  
the other1 so  that by twirling round   
the card the two are seen at the same   
time in  their usual mode of            
combination4 ,the body of a ,turk is    
drawn on one  side1 and his head on the 

reverse1 and by the rotation of the card
 the  head is replaced upon his         
shoulders4 ,the principle of this       
illusion  may be extended to many other 
contrivances4 ,part of a sentence may be
  written on one side of a card1 and the
 rest on the reverse4 ,particular       
letters may be given on one side1 and   
others upon the other1 or even  halves  
or parts of each letter may be put upon 
each side1 or all these  contrivances   
may be combined1 so that the sentiment  
which they express  can be understood   
only when all the scattered parts are   
united by the  revolution of the card4  
,as the revolving card is virtually     
transparent1 so that bodies beyond  it  
can be seen through it1 the power of the
 illusion might be greatly  extended by 
introducing into the picture other      
figures1 either animate  or inanimate4  
,the setting sun1 for example1 might be 
introduced into a  landscape2 part of   
the flame of a fire might be seen to    
issue from the  crater of a volcano1 and

 cattle grazing in a field might make   
part of  the revolutionary landscape4   
,for such purposes1 however1 the form of
  the instrument would require to be    
completely changed1 and the rotation    
should be effected round a standing axis
 by wheels and pinions1 and a  screen   
placed in front of the revolving plane  
with open compartments  or apertures1   
through which the principal figures     
would appear4 ,had  the principle of    
this instrument been known to the       
ancients1 it would  doubtless have      
formed a powerful engine of delusion in 
their temples1  and might have been more
 effective than the optical means which 
they  seem to have employed for         
producing the apparitions of their gods4
    ,in certain diseased conditions of  
the eye1 effects of a very remarkable   
kind are produced4 ,the faculty of      
seeing objects double is too common  to 
be noticed as remarkable2 and though it 
may take place with only one  eye1 yet1 
as it generally arises from a transient 

inability to direct  the axis of both   
eyes to the same point1 it excites      
little notice4  ,that state of the eye1 
however1 in which we lose sight of half 
of  every object at which we look1 is   
more alarming and more likely to be     
ascribed to the disappearance of part of
 the object than to a defect  of sight4 
,dr4 ,wollaston1 who experienced this   
defect twice1 informs us  that1 after   
taking violent exercise1 he 8suddenly   
found that he could  see but half of a  
man whom he met1 and that on attempting 
to read the  name of ,,johnson over a   
door1 he saw only ,,son1 the            
commencement of the  name being wholly  
obliterated from his view40 ,in this    
instance1 the  part of the object which 
disappeared was towards his left2 but on
 a  second occurrence of the same       
affection1 the part which disappeared   
was towards his right4 ,there are many  
occasions on which this defect  of the  
eye might alarm the person who witnessed
 it for the first time4  ,at certain    

distances from the eye one of two       
persons would necessarily  disappear2   
and by a slight change of position      
either in the observer  or the person   
observed1 the person that vanished would
 reappear1 while  the other would       
disappear in his turn4 ,the             
circumstances under which  these        
evanescences would take place could not 
be supposed to occur to  an ordinary    
observer1 even if he should be aware    
that the cause had its  origin in       
himself4 ,when a phenomenon so strange  
is seen by a person in  perfect health1 
as it generally is1 and who has never   
had occasion to  distrust the testimony 
of his senses1 he can scarcely refer it 
to any  other cause than a supernatural 
one4    ,among the affections of the eye
 which not only deceive the person who  
is subject to them1 but those also who  
witness their operation1 may be         
enumerated the insensibility of the eye 
to particular colours4 ,this  defect is 
not accompanied with any imperfection of

 vision1 or connected  with any disease 
either of a local or a general nature1  
and it has  hitherto been observed in   
persons who possess a strong and a sharp
  sight4 ,mr4 ,huddart has described the
 case of one ,harris1 a shoemaker  at   
,maryport in ,cumberland1 who was       
subject to this defect in a very        
remarkable degree4 ,he seems to have    
been insensible to every colour1  and to
 have been capable of recognizing only  
the two opposite tints  of black and    
white4 8,his first suspicion of this    
defect arose  when he was about four    
years old4 ,having by accident found in 
the  street a child's stocking1 he      
carried it to a neighbouring house to   
inquire for the owner4 ,he observed the 
people call it a red stocking1  though  
he did not understand why they gave it  
that denomination1 as he  himself       
thought it completely described by being
 called a stocking4  ,the circumstance1 
however1 remained in his memory1 and1   
with other  subsequent observations1 led

 him to the knowledge of his defect4 ,he
  observed also1 that when young1 other 
children could discern cherries  on a   
tree by some pretended difference of    
colour1 though he could only            
distinguish them from the leaves by     
their difference of size and shape4  ,he
 observed also1 that by means of this   
difference of colour1 they  could see   
the cherries at a greater distance than 
he could1 though he  could see other    
objects at as great a distance as they1 
that is1 where  the sight was not       
assisted by the colour40 ,harris had two
 brothers1  whose perception of colours 
was nearly as defective as his own4 ,one
 of  these1 whom ,mr4 ,huddart examined1
 constantly mistook light green for     
yellow1 and orange for grass green4     
,mr4 ,scott has described1 in the       
,philosophical ,transactions1 his own   
defect in perceiving colours4 ,he states
 that he does not know any  green in the
 world2 that a pink colour and a pale   
blue are  perfectly alike2 that he has  

often thought a full red and a full     
green a good match2 that he is sometimes
 baffled in distinguishing  a full      
purple from a deep blue1 but that he    
knows light1 dark1  and middle yellows1 
and all degrees of blue except sky-blue4
 8,i  married my daughter to a genteel1 
worthy man1 a few years ago2 the  day   
before the marriage1 he came to my house
 dressed in a new suit of  fine cloth   
clothes4 ,i was much displeased that he 
should come1 as ,i  supposed1 in black1 
and said that he should go back to      
change his  colour4 ,but my daughter    
said1 ,no1 no2 the colour is very       
genteel2 that  it was my eyes that      
deceived me4 ,he was a gentleman of the 
law1 in a  fine1 rich1 claret-coloured  
dress1 which is as much black to my eyes
 as  any black that ever was dyed40 ,mr4
 ,scott's father1 his maternal uncle1   
one of his sisters1 and her two sons1   
had all the same imperfection4  ,dr4    
,nichol has recorded a case where a     
naval officer purchased a  blue uniform 

coat and waistcoat with red breeches to 
match the  blue1 and ,mr4 ,harvey       
describes the case of a tailor at       
,plymouth1 who  on one occasion repaired
 an article of dress with crimson in    
place  of black silk1 and on another    
patched the elbow of a blue coat  with a
 piece of crimson cloth4 ,it deserves to
 be remarked that our  celebrated       
countrymen1 the late ,mr4 ,dugald       
,stewart1 ,mr4 ,dalton1 and  ,mr4       
,troughton1 have a similar difficulty in
 distinguishing colours4  ,mr4 ,stewart 
discovered this defect when one of his  
family was admiring  the beauty of a    
,siberian crab-apple1 which he could not
 distinguish  from the leaves but by its
 form and size4 ,mr4 ,dalton cannot     
distinguish  blue from pink1 and the    
solar spectrum consists only of two     
colours1  yellow and blue4 ,mr4         
,troughton regards red ruddy pinks1 and 
brilliant oranges1 as yellows1 and      
greens as blues1 so that he  is capable 
only of appreciating blue and yellow    

colours4    ,in all those cases which   
have been carefully studied1 at least in
  three of them1 in which ,i have had   
the advantage of making personal        
observations1 namely1 those of ,mr4     
,troughton1 ,mr4 ,dalton1 and ,mr4      
,liston1 the eye is capable of seeing   
the whole of the prismatic  spectrum1   
the red space appearing to be yellow4   
,if the red space  consisted of         
homogeneous or simple red rays1 we      
should be led to infer  that the eyes in
 question were not insensible to red    
light1 but were  merely incapable of    
discriminating between the impressions  
of red and  yellow light4 ,i have lately
 shown1 however1 that the prismatic     
spectrum  consists of three equal and   
coincident spectra of red1 yellow1 and  
blue light1 and consequently1 that much 
yellow and a small portion  of blue     
light exist in the red space2 and hence 
it follows1 that those  eyes which see  
only two colours1 viz4 yellow and blue1 
in the  spectrum1 are really insensible 

to the red light of the spectrum1 and   
see only the yellow with the small      
portion of blue with which the red  is  
mixed4 ,the faintness of the yellow     
light which is thus seen in the  red    
space1 confirms the opinion that the    
retina has not appreciated the          
influence of the simple red rays4    ,if
 one of the two travellers who1 in the  
fable of the chameleon1 are  made to    
quarrel about the colour of that        
singular animal1 had happened  to       
possess this defect of sight1 they would
 have encountered at every  step of     
their journey1 new grounds of           
dissension1 without the chance  of      
finding an umpire who could pronounce a 
satisfactory decision4  ,under certain  
circumstances1 indeed1 the arbiter might
 set aside the  opinions of both the    
disputants1 and render it necessary to  
appeal to  some higher authority1       
---- to beg he'd tell them if he knew   
,whether the thing was red or blue4     
,illustration3 ,fig4 #b4    ,in the     

course of writing the preceding         
observations an ocular illusion         
occurred to myself of so extraordinary a
 nature1 that ,i am convinced  it never 
was seen before1 and ,i think it far    
from probable that it  will ever be seen
 again4 ,upon directing my eyes to the  
candles that  were standing before me1  
,i was surprised to observe1 apparently 
among  my hair1 and nearly straight     
above my head1 and far without the range
  of vision1 a distinct image of one of 
the candles inclined about #de  to the  
horizon1 as shown at ,a in ,fig4 #b4    
,the image was as distinct and  perfect 
as if it had been formed by reflection  
from a piece of mirror  glass1 though of
 course much less brilliant1 and the    
position of the  image proved that it   
must be formed by reflection from a     
perfectly flat  and highly polished     
surface4 ,but where such a surface could
 be placed1  and how1 even if it were   
fixed1 it could reflect the image of the
  candle up through my head1 were       

difficulties not a little perplexing4   
,thinking that it might be something    
lodged in the eyebrow1 ,i covered  it up
 from the light1 but the image still    
retained its place4 ,i then  examined   
the eyelashes with as little success1   
and was driven to the  extreme          
supposition that a crystallization was  
taking place in some  part of the       
aqueous humour of the eye1 and that the 
image was formed by  the reflection of  
the light of the candle from one of the 
crystalline  faces4 ,in this state of   
uncertainty1 and1 ,i may add1 of        
anxiety1 for  this last supposition was 
by no means an agreeable one1 ,i set    
myself  down to examine the phenomenon  
experimentally4 ,i found that the image 
varied its place by the motion of the   
head and of the eyeball1 which  proved  
that it was either attached to the      
eyeball or occupied a place  where it   
was affected by that motion4 ,upon      
inclining the candle at  different      
angles1 the image suffered corresponding

 variations of  position4 ,in order to  
determine the exact place of the        
reflecting  substance1 ,i now took an   
opaque circular body and held it between
  the eye and the candle till it        
eclipsed the mysterious image4 ,by      
bringing the body nearer and nearer the 
eyeball till its shadow became          
sufficiently distinct to be seen1 it was
 easy to determine the locality  of the 
reflector1 because the shadow of the    
opaque body must fall  upon it whenever 
the image of the candle was eclipsed4   
,in this way ,i  ascertained that the   
reflecting body was in the upper        
eyelash2 and ,i  found1 that1 in        
consequence of being disturbed1 it had  
twice changed  its inclination1 so as to
 represent a vertical candle in the     
horizontal  position ,b1 and afterwards 
in the inverted position ,c4 ,still1    
however1  ,i sought for it in vain1 and 
even with the aid of a magnifier ,i     
could not discover it4 ,at last1        
however1 ,mrs4 ,b41 who possesses the   

perfect vision of short-sighted persons1
 discovered1 after repeated             
examinations1 between two eyelashes1 a  
minute speck1 which1 upon being  removed
 with great difficulty1 turned out to be
 a chip of red wax not  above the       
hundredth part of an inch in diameter1  
and having its surface  so perfectly    
flat and so highly polished that ,i     
could see in it the  same image of the  
candle1 by placing it extremely near the
 eye4 ,this  chip of wax had no doubt   
received its flatness and its polish    
from the  surface of a seal1 and had    
started into my eye when breaking the   
seal  of a letter4    ,that this        
reflecting substance was the cause of   
the image of the  candle1 cannot admit  
of a doubt2 but the wonder still remains
 how the  images which it formed        
occupied so mysterious a place as to be 
seen  without the range of vision1 and  
apparently through the head4 ,in order  
to explain this1 let m n1 ,fig4 #b1 be a
 lateral view of the eye4 ,the  chip of 

wax was placed at m at the root of the  
eyelashes1 and being  nearly in contact 
with the outer surface of the cornea1   
the light of  the candle1 which it      
reflected1 passed very obliquely through
 the pupil  and fell upon the retina    
somewhere to the left of n1 very near   
where  the retina terminates2 but a ray 
thus falling obliquely on the retina  is
 seen1 in virtue of the law of visible  
direction already explained1  in a line 
n ,c perpendicular to the retina at the 
point near n1  where the ray fell4      
,hence the candle was necessarily seen  
through the  head as it were of the     
observer1 and without the range of      
ordinary  vision4 ,the comparative      
brightness of the reflected image still 
surprises me2 but even this1 if the     
image really was brighter1 may  be      
explained by the fact1 that it was      
formed on a part of the retina  upon    
which light had never before fallen1 and
 which may therefore  be supposed to be 
more sensible1 than the parts of the    

membrane in  constant use1 to luminous  
impressions4    ,independent of its     
interest as an example of the marvellous
 in vision1  the preceding fact may be  
considered as a proof that the retina   
retains  its power to its very          
termination near the ciliary processes1 
and that  the law of visible direction  
holds true even without the range of    
ordinary vision4 ,it is therefore       
possible that a reflecting surface      
favourably placed on the outside of the 
eye1 or that a reflecting  surface in   
the inside of the eye1 may cause a      
luminous image to fall  nearly on the   
extreme margin of the retina1 the       
consequence of which  would be1 that it 
would be seen in the back of the head1  
half way  between a vertical and a      
horizontal line4          ,,letter      
,,iii4     ,subject of spectral         
illusions--,recent and interesting case 
of ,mrs4   ,a4--,her first illusion     
affecting the ear--,spectral apparition 
of   her husband--,spectral apparition  

of a cat--,apparition of a near and     
living relation in grave-clothes1 seen  
in a looking-glass--,other   illusions1 
affecting the ear--,spectre of a        
deceased friend   sitting in an         
easy-chair--,spectre of a coach-and-four
 filled with   skeletons--,accuracy and 
value of the preceding cases--,state of 
health   under which they               
arose--,spectral apparitions are        
pictures on the   retina--,the ideas of 
memory and imagination are also pictures
 on the   retina--,general views of the 
subject--,approximate explanation of    
spectral apparitions4      ,the         
preceding account of the different      
sources of illusion to which the  eye is
 subject is not only useful as          
indicating the probable cause of  any   
individual deception1 but it has a      
special importance in preparing  the    
mind for understanding those more vivid 
and permanent spectral  illusions to    
which some individuals have been either 
occasionally or  habitually subject4    

,in these lesser phenomena1 we find the 
retina so powerfully influenced  by     
external impressions1 as to retain the  
view of visible objects  long after they
 are withdrawn3 we observe it to be so  
excited by  local pressures of which we 
sometimes know neither the nature nor   
the  origin1 as to see in total darkness
 moving and shapeless masses of         
coloured light2 and we find1 as in the  
case of ,sir ,isaac ,newton1 and        
others1 that the imagination has the    
power of reviving the impressions  of   
highly luminous objects1 months and even
 years after they were  first made4     
,from such phenomena1 the mind feels it 
to be no violent  transition to pass to 
those spectral illusions which1 in      
particular  states of health1 have      
haunted the most intelligent            
individuals1 not  only in the broad     
light of day1 but in the very heart of  
the social  circle4    ,this curious    
subject has been so ably and fully      
treated in your  ,letters on            

,demonology1 that it would be           
presumptuous in me to resume  any part  
of it on which you have even touched2   
but as it forms a  necessary branch of a
 ,treatise on ,natural ,magic1 and as   
one of the most  remarkable cases on    
record has come within my own knowledge1
 ,i shall  make no apology for giving a 
full account of the different spectral  
appearances which it embraces1 and of   
adding the results of a series of       
observations and experiments on which ,i
 have been long occupied1 with  the view
 of throwing some light on this         
remarkable class of phenomena4    ,a few
 years ago1 ,i had occasion to spend    
some days under the same roof  with the 
lady to whose case ,i have above        
referred4 ,at that time she  had seen no
 spectral illusions1 and was acquainted 
with the subject  only from the         
interesting volume of ,dr4 ,hibbert4 ,in
 conversing with  her about the cause of
 these apparitions1 ,i mentioned1 that  
if she  should ever see such a thing1   

she might distinguish a genuine ghost1  
existing externally1 and seen as an     
external object1 from one created  by   
the mind1 by merely pressing one eye or 
straining them both1 so  as to see      
objects double2 for in this case the    
external object or  supposed apparition 
would invariably be doubled1 while the  
impression  on the retina created by the
 mind would remain single4 ,this        
observation  recurred to her mind when  
she unfortunately became subject to the 
same  illusions2 but she was too well   
acquainted with their nature to require 
any such evidence of their mental       
origin2 and the state of agitation      
which generally accompanies them seems  
to have prevented her from  making the  
experiment as a matter of curiosity4    
#a4 ,the first illusion to which ,mrs4  
,a4 was subject was one which  affected 
only the ear4 ,on the #bfth of          
,december1 #ahcj1 about half-past  four 
in the afternoon1 she was standing near 
the fire in the hall1  and on the point 

of going up stairs to dress1 when she   
heard1 as she  supposed1 her husband's  
voice calling her by name1 8---- ,come  
here6  come to me60 ,she imagined that  
he was calling at the door to have it   
opened1 but upon going there and opening
 the door she was surprised to  find no 
person there4 ,upon returning to the    
fire1 she again heard the  same voice   
calling out very distinctly and loudly1 
8---- ,come1 come  here60 ,she then     
opened two doors of the same room1 and  
upon seeing no  person she returned to  
the fire-place4 ,after a few moments she
 heard  the same voice still calling1   
8---- ---- ,come to me1 come6 come      
away60  in a loud1 plaintive1 and       
somewhat impatient tone4 ,she answered  
as  loudly1 8,where are you8 ,i don't   
know where you are20 still imagining    
that he was somewhere in search of her3 
but receiving no answer1 she  shortly   
went up stairs4 ,on ,mr4 ,a4's return to
 the house1 about half an  hour         
afterwards1 she inquired why he called  

to her so often1 and where  he was2 and 
she was1 of course1 greatly surprised to
 learn that he had  not been near the   
house at the time4 ,a similar illusion1 
which excited  no particular notice at  
the time1 occurred to ,mrs4 ,a4 when    
residing at  ,florence about ten years  
before1 and when she was in perfect     
health4  ,when she was undressing after 
a ball1 she heard a voice call her      
repeatedly by name1 and she was at that 
time unable to account for it4    #b4   
,the next illusion which occurred to    
,mrs4 ,a4 was of a more alarming        
character4 ,on the #cjth of ,december1  
about four o'clock in the  afternoon1   
,mrs4 ,a4 came down stairs into the     
drawing-room1 which she  had quitted    
only a few minutes before1 and on       
entering the room she  saw her husband1 
as she supposed1 standing with his back 
to the fire4  ,as he had gone out to    
take a walk about half an hour before1  
she was  surprised to see him there1 and
 asked him why he had returned so  soon4

 ,the figure looked fixedly at her with 
a serious and thoughtful  expression of 
countenance1 but did not speak4         
,supposing that his mind  was absorbed  
in thought1 she sat down in an arm-chair
 near the fire1  and within two feet at 
most of the figure1 which she still saw 
standing  before her4 ,as its eyes1     
however1 still continued to be fixed    
upon her1  she said1 after the lapse of 
a few minutes1 8,why don't you          
speak1----80  ,the figure immediately   
moved off towards the window at the     
further end  of the room1 with its eyes 
still gazing on her1 and it passed so   
very  close to her in doing so1 that she
 was struck by the circumstance of      
hearing no step nor sound1 nor feeling  
her clothes brushed against1  nor even  
any agitation in the air4 ,although she 
was now convinced that  the figure was  
not her husband1 yet she never for a    
moment supposed  that it was anything   
supernatural1 and was soon convinced    
that it was  a spectral illusion4 ,as   

soon as this conviction had established 
itself  in her mind1 she recollected the
 experiment which ,i had suggested1 of  
trying to double the object3 but before 
she was able distinctly to do  this1 the
 figure had retreated to the window1    
where it disappeared4  ,mrs4 ,a4        
immediately followed it1 shook the      
curtains and examined the  window1 the  
impression having been so distinct and  
forcible that she  was unwilling to     
believe that it was not a reality4      
,finding1 however1  that the figure had 
no natural means of escape1 she was     
convinced that  she had seen a spectral 
apparition like those recorded in ,dr4  
,hibbert's  work1 and she consequently  
felt no alarm or agitation4 ,the        
appearance  was seen in bright daylight1
 and lasted four or five minutes4 ,when 
the  figure stood close to her it       
concealed the real objects behind it1   
and  the apparition was fully as vivid  
as the reality4    #c4 ,on these two    
occasions ,mrs4 ,a4 was alone1 but when 

the next phantasm  appeared her husband 
was present4 ,this took place on the    
#dth of  ,january1 #ahcj4 ,about ten    
o'clock at night1 when ,mr4 and ,mrs4   
,a4 were  sitting in the drawing-room1  
,mr4 ,a4 took up the poker to stir the  
fire1  and when he was in the act of    
doing this1 ,mrs4 ,a4 exclaimed1 8,why  
there's the cat in the room60 8,where80 
asked ,mr4 ,a4 8,there1 close to  you10 
she replied4 8,where80 he repeated4     
8,why on the rug1 to be sure1  between  
yourself and the coal-scuttle40 ,mr4    
,a41 who had still the  poker in his    
hand1 pushed it in the direction        
mentioned3 8,take care10  cried ,mrs4   
,a41 8take care1 you are hitting her    
with the poker40 ,mr4  ,a4 again asked  
her to point out exactly where she saw  
the cat4 ,she  replied1 0,why sitting up
 there close to your feet on the rug4   
,she is  looking at me4 ,it is          
,kitty--come here1 ,kitty60--,there were
 two cats  in the house1 one of which   
went by this name1 and they were rarely 

if  ever in the drawing-room4 ,at this  
time ,mrs4 ,a4 had no idea that the     
sight of the cat was an illusion4 ,when 
she was asked to touch it1 she  got up  
for the purpose1 and seemed as if she   
were pursuing something  which moved    
away4 ,she followed a few steps1 and    
then said1 8,it has gone  under the     
chair40 ,mr4 ,a4 assured her it was an  
illusion1 but she would  not believe it4
 ,he then lifted up the chair1 and ,mrs4
 ,a4 saw nothing  more of it4 ,the room 
was then searched all over1 and nothing 
found in  it4 ,there was a dog lying on 
the hearth1 who would have betrayed     
great  uneasiness if a cat had been in  
the room1 but he lay perfectly quiet4   
,in order to be quite certain1 ,mr4 ,a4 
rang the bell1 and sent for the  two    
cats1 both of which were found in the   
housekeeper's room4    #d4 ,about a     
month after this occurrence1 ,mrs4 ,a41 
who had taken a  somewhat fatiguing     
drive during the day1 was preparing to  
go to bed  about eleven o'clock at      

night1 and1 sitting before the          
dressing-glass1  was occupied in        
arranging her hair4 ,she was in a       
listless and drowsy  state of mind1 but 
fully awake4 ,when her fingers were in  
active motion  among the papillotes1 she
 was suddenly startled by seeing in the 
mirror the figure of a near relation1   
who was then in ,scotland and in        
perfect health4 ,the apparition appeared
 over her left shoulder1 and  its eyes  
met hers in the glass4 ,it was enveloped
 in grave-clothes1  closely pinned1 as  
is usual with corpses1 round the head1  
and under  the chin1 and though the eyes
 were open1 the features were solemn and
  rigid4 ,the dress was evidently a     
shroud1 as ,mrs4 ,a4 remarked even the  
punctured pattern usually worked in a   
peculiar manner round the edges  of that
 garment4 ,mrs4 ,a4 described herself as
 at the time sensible of  a feeling like
 what we conceive of fascination1       
compelling her for a  time to gaze on   
this melancholy apparition1 which was as

 distinct and  vivid as any reflected   
reality could be1 the light of the      
candles upon  the dressing-table        
appearing to shine fully upon its face4 
,after a few  minutes1 she turned round 
to look for the reality of the form over
 her  shoulder2 but it was not visible1 
and it had also disappeared from the    
glass when she looked again in that     
direction4    #e4 ,in the beginning of  
,march1 when ,mr4 ,a4 had been about a  
fortnight  from home1 ,mrs4 ,a4         
frequently heard him moving near her4   
,nearly every  night1 as she lay awake1 
she distinctly heard sounds like his    
breathing  hard on the pillow by her    
side1 and other sounds such as he might 
make  while turning in bed4    #f4 ,on  
another occasion1 during ,mr4 ,a4's     
absence1 while riding with  a neighbour1
 ,mr4----1 she heard his voice          
frequently as if he were  riding by his 
side4 ,she heard also the tramp of his  
horse's feet1 and  was almost puzzled by
 hearing him address her at the same    

time with  the person really in company4
 ,his voice made remarks on the scenery1
  improvements1 c41 such as he probably 
should have done had he been  present4  
,on this occasion1 however1 there was no
 visible apparition4    #g4 ,on the     
#agth ,march1 ,mrs4 ,a4 was preparing   
for bed4 ,she had dismissed  her maid1  
and was sitting with her feet in hot    
water4 ,having an  excellent memory1 she
 had been thinking upon and repeating to
 herself  a striking passage in the     
,edinburgh ,review1 when on raising her 
eyes1  she saw seated in a large        
easy-chair before her the figure of a   
deceased friend1 the sister of ,mr4 ,a4 
,the figure was dressed as had  been    
usual with her1 with great neatness1 but
 in a gown of a peculiar  kind1 such as 
,mrs4 ,a4 had never seen her wear1 but  
exactly such as had  been described to  
her by a common friend as having been   
worn by ,mr4  ,a4's sister during her   
last visit to ,england4 ,mrs4 ,a4 paid  
particular  attention to the dress1 air1

 and appearance of the figure1 which sat
  in an easy attitude in the chair1     
holding a handkerchief in one hand4     
,mrs4 ,a4 tried to speak to it1 but     
experienced a difficulty in doing  so2  
and in about three minutes the figure   
disappeared4 ,about a minute            
afterwards1 ,mr4 ,a4 came into the room1
 and found ,mrs4 ,a4 slightly  nervous1 
but fully aware of the delusive nature  
of the apparition4 ,she  described it as
 having all the vivid colouring and     
apparent reality  of life2 and for some 
hours preceding this and other visions1 
she  experienced a peculiar sensation in
 her eyes1 which seemed to be  relieved 
when the vision had ceased4    #h4 ,on  
the #eth ,october1 between one and two  
o'clock in the morning1 ,mr4  ,a4 was   
awoke by ,mrs4 ,a41 who told him that   
she had just seen the figure  of his    
deceased mother draw aside the          
bedcurtains and appear between  them4   
,the dress and the look of the          
apparition were precisely those in      

which ,mr4 ,a4's mother had been last   
seen by ,mrs4 ,a4 at ,paris1 in #ahbd4  
#i4 ,on the #aath ,october1 when sitting
 in the drawing-room1 on one side  of   
the fire-place1 she saw the figure of   
another deceased friend  moving towards 
her from the window at the further end  
of the room4 ,it  approached the        
fire-place1 and sat down in the chair   
opposite4 ,as there  were several       
persons in the room at the time1 she    
describes the idea  uppermost in her    
mind to have been a fear lest they      
should be alarmed  at her staring1 in   
the way she was conscious of doing1 at  
vacancy1 and  should fancy her intellect
 disordered4 ,under the influence of    
this  fear1 and recollecting a story of 
a similar effect in your work on        
,demonology1 which she had lately read1 
she summoned up the requisite           
resolution to enable her to cross the   
space before the fire-place1 and  seat  
herself in the same chair with the      
figure4 ,the apparition remained        

perfectly distinct till she sat down1 as
 it were1 in its lap1 when it  vanished4
    #aj4 ,on the #bfth of the same      
month1 about two ,p4,m41 ,mrs4  ,a4 was 
sitting in a chair by the window in the 
same room with her  husband4 ,he heard  
her exclaim--0,what have ,i seen80 ,and 
on looking at  her1 he observed a       
strange expression in her eyes and      
countenance4  ,a carriage-and-four had  
appeared to her to be driving up the    
entrance-road to the house4 ,as it      
approached1 she felt inclined to  go up 
stairs to prepare to receive company1   
but1 as if spellbound1  she was unable  
to move or speak4 ,the carriage         
approached1 and as it  arrived within a 
few yards of the window1 she saw the    
figures of  the postilions and the      
persons inside take the ghastly         
appearance of  skeletons and other      
hideous figures4 ,the whole then        
vanished entirely1  when she uttered the
 above-mentioned exclamation4    #aa4   
,on the morning of the #cjth ,october1  

when ,mrs4 ,a4 was sitting in her  own  
room with a favourite dog in her lap1   
she distinctly saw the same  dog moving 
about the room during the space of about
 a minute or rather  more4    #ab4 ,on  
the #crd ,december1 about nine ,p4,m41  
when ,mr4 and ,mrs4 ,a4 were  sitting   
near each other in the drawing-room     
occupied in reading1 ,mr4  ,a4 felt a   
pressure on his foot4 ,on looking up he 
observed ,mrs4 ,a4's  eyes fixed with a 
strong and unnatural stare on a chair   
about nine  or ten feet distant4 ,upon  
asking her what she saw1 the expression 
of  her countenance changed1 and upon   
recovering herself1 she told ,mr4 ,a4   
that she had seen his brother1 who was  
alive and well at the moment in         
,london1 seated in the opposite chair1  
but dressed in grave-clothes1 and  with 
a ghastly countenance1 as if scarcely   
alive4    ,such is a brief account of   
the various spectral illusions observed 
by  ,mrs4 ,a4 ,in describing them ,i    
have used the very words employed by her

  husband in his communications to me on
 the subject2#e and the reader  may be  
assured that the descriptions are       
neither heightened by fancy1  nor       
amplified by invention4 ,the high       
character and intelligence of  the lady1
 and the station of her husband in      
society1 and as a man of  learning and  
science1 would authenticate the most    
marvellous narrative1  and satisfy the  
most scrupulous mind1 that the case has 
been  philosophically as well as        
faithfully described4 ,in narrating     
events  which we regard as of a         
supernatural character1 the mind has a  
strong  tendency to give more prominence
 to what appears to itself the most     
wonderful2 but from the very same cause1
 when we describe extraordinary  and    
inexplicable phenomena which we believe 
to be the result of natural  causes1 the
 mind is prone to strip them of their   
most marvellous  points1 and bring them 
down to the level of ordinary events4   
,from the  very commencement of the     

spectral illusions seen by ,mrs4 ,a41   
both she  and her husband were well     
aware of their nature and origin1 and   
both  of them paid the most minute      
attention to the circumstances which    
accompanied them1 not only with the view
 of throwing light upon so  curious a   
subject1 but for the purpose of         
ascertaining their connection  with the 
state of health under which they        
appeared4     #e ,edinburgh ,journal of 
,science1 ,new ,series1 ,no4 iv4 pp4    
#bah1 #bai1   ,no4 vi41 p4 #bdd1 and    
,no4 viii41 p4 #bfa4    ,as the spectres
 seen by ,nicolai and others had their  
origin in bodily  indisposition1 it     
becomes interesting to learn the state  
of ,mrs4 ,a4's  health when she was     
under the influence of these illusions4 
,during the  six weeks within which the 
first three illusions took place1 she   
had  been considerably reduced and      
weakened by a troublesome cough1 and the
  weakness which this occasioned was    
increased by her being prevented  from  

taking a daily tonic4 ,her general      
health had not been strong1  and long   
experience has put it beyond a doubt1   
that her indisposition  arises from a   
disordered state of the digestive       
organs4 ,mrs4 ,a4 has  naturally a      
morbidly sensitive imagination1 which so
 painfully affects  her corporeal       
impressions1 that the account of any    
person having  suffered severe pain by  
accident or otherwise1 occasionally     
produces  acute twinges of pain in the  
corresponding parts of her person4 ,the 
account1 for example1 of the amputation 
of an arm will produce an  instantaneous
 and severe sense of pain in her own    
arm4 ,she is subject  to talk in her    
sleep with great fluency1 to repeat long
 passages of  poetry1 particularly when 
she is unwell1 and even to cap verses   
for  half an hour together1 never       
failing to quote lines beginning with   
the  final letter of the preceding one  
till her memory is exhausted4           
,although it is not probable that we    

shall ever be able to understand  the   
actual manner in which a person of sound
 mind beholds spectral  apparitions in  
the broad light of day1 yet we may      
arrive at such a  degree of knowledge on
 the subject as to satisfy rational     
curiosity1  and to strip the phenomena  
of every attribute of the marvellous4   
,even the vision of natural objects     
presents to us insurmountable           
difficulties1 if we seek to understand  
the precise part which the mind         
performs in perceiving them2 but the    
philosopher considers that he has  given
 a satisfactory explanation of vision1  
when he demonstrates that  distinct     
pictures of external objects are painted
 on the retina1 and  that this membrane 
communicates with the brain by means of 
nerves of  the same substance as itself1
 and of which it is merely an expansion4
  ,here we reach the gulf which human   
intelligence cannot pass2 and if the    
presumptuous mind of man shall dare to  
extend its speculations farther1  it    

will do it only to evince its incapacity
 and mortify its pride4    ,in his      
admirable work on this subject1 ,dr4    
,hibbert has shown that  spectral       
apparitions are nothing more than ideas 
or the recollected  images of the mind1 
which1 in certain states of bodily      
indisposition1  have been rendered more 
vivid than actual impression1 or1 to use
 other  words1 that the pictures in the 
8mind's eye0 are more vivid than the    
pictures in the body's eye4 ,this       
principle has been placed by ,dr4       
,hibbert beyond the reach of doubt2 but 
,i propose to go much farther1  and to  
show that the 8mind's eye0 is actually  
the body's eye1 and that  the retina is 
the common tablet on which both classes 
of impressions  are painted1 and by     
means of which they receive their visual
 existence  according to the same       
optical laws4 ,nor is this true merely  
in the  case of spectral illusions2 it  
holds good of all ideas recalled by  the
 memory or created by the imagination1  

and may be regarded as a  fundamental   
law in the science of pneumatology4     
,it would be out of place in a work like
 this to adduce the experimental        
evidence on which it rests1 or even to  
explain the manner in which the         
experiments themselves must be          
conducted3 but ,i may state in general1 
that the spectres conjured up by the    
memory or the fancy have always  a      
8local habitation10 and that they appear
 in front of the eye1 and  partake in   
its movements exactly like the          
impressions of luminous  objects1 after 
the objects themselves are withdrawn4   
,in the healthy state of the mind and   
body1 the relative intensity of  these  
two classes of impressions on the retina
 is nicely adjusted4 ,the  mental       
pictures are transient and comparatively
 feeble1 and in ordinary  temperaments  
are never capable of disturbing or      
effacing the direct  images of visible  
objects4 ,the affairs of life could not 
be carried on  if the memory were to    

intrude bright representations of the   
past into  the domestic scene1 or       
scatter them over the external          
landscape4 ,the  two opposite           
impressions1 indeed1 could not co-exist3
 the same nervous  fibre which is       
carrying from the brain to the retina   
the figures of  memory1 could not at the
 same instant be carrying back the      
impressions  of external objects from   
the retina to the brain4 ,the mind      
cannot  perform two different functions 
at the same instant1 and the direction  
of its attention to one of the two      
classes of impressions necessarily      
produces the extinction of the other3   
but so rapid is the exercise  of mental 
power1 that the alternate appearance and
 disappearance  of the two contending   
impressions are no more recognized than 
the  successive observations of external
 objects during the twinkling of  the   
eyelids4 ,if we look for example at the 
faade of ,st4 ,paul's1 and  without     
changing our position call to mind the  

celebrated view of  ,mont ,blanc from   
,lyons1 the picture of the cathedral1   
though actually  impressed upon the     
retina1 is momentarily lost sight of by 
the mind1  exactly like an object seen  
by indirect vision2 and during the      
instant  the recollected image of the   
mountain1 towering over the subjacent   
range1 is distinctly seen1 but in a tone
 of subdued colouring and  indistinct   
outline4 ,when the purpose of its recall
 is answered1 it  quickly disappears1   
and the picture of the cathedral again  
resumes the  ascendancy4    ,in darkness
 and solitude1 when external objects no 
longer interfere  with the pictures of  
the mind1 they become more vivid and    
distinct2  and in the state between     
waking and sleeping the intensity of the
  impressions approaches to that of     
visible objects4 ,with persons of       
studious habits1 who are much occupied  
with the operations of their  own minds1
 the mental pictures are much more      
distinct than in ordinary  persons2 and 

in the midst of abstract thought1       
external objects even  cease to make any
 impression on the retina4 ,a           
philosopher absorbed in  his            
contemplations experiences a temporary  
privation of the use of  his senses4    
,his children or his servants will enter
 the room directly  before his eyes     
without being seen4 ,they will speak to 
him without  being heard2 and they will 
even try to rouse him from his reverie  
without being felt2 although his eyes1  
his ears1 and his nerves  actually      
receive the impressions of light1 sound1
 and touch4 ,in such  cases1 however1   
the philosopher is voluntarily pursuing 
a train of  thought on which his mind is
 deeply interested2 but even ordinary   
men1 not much addicted to speculations  
of any kind1 often perceive in  their   
mind's eye the pictures of deceased or  
absent friends1 or even  ludicrous      
creations of fancy1 which have no       
connexion whatever with the  train of   
their thoughts4 ,like spectral          

apparitions they are entirely           
involuntary1 and though they may have   
sprung from a regular series of         
associations1 yet it is frequently      
impossible to discover a single link  in
 the chain4    ,if it be true1 then1    
that the pictures of the mind and       
spectral  illusions are equally         
impressions upon the retina1 the latter 
will  differ in no respect from the     
former1 but in the degree of vividness  
with which they are seen2 and those     
frightful apparitions become  nothing   
more than our ordinary ideas1 rendered  
more brilliant by some  accidental and  
temporary derangement of the vital      
functions4 ,their  very vividness1 too1 
which is their only characteristic1 is  
capable  of explanation4 ,i have already
 shown that the retina is rendered  more
 sensible to light by voluntary local   
pressure1 as well as by  the involuntary
 pressure of the blood-vessels behind   
it2 and if1 by  looking at the sun1 we  
impress upon the retina a coloured image

 of that  luminary1 which is seen even  
when the eye is shut1 we may by pressure
  alter the colour of that image1 in    
consequence of having increased the     
sensibility of that part of the retina  
on which it is impressed4 ,hence  we may
 readily understand how the vividness of
 the mental pictures must  be increased 
by analogous causes4    ,in the case    
both of ,nicolai and ,mrs4 ,a4 the      
immediate cause of the  spectres was a  
deranged action of the stomach4 ,when   
such a derangement  is induced by       
poison1 or by substances which act as   
poisons1 the retina  is peculiarly      
affected1 and the phenomena of vision   
are singularly  changed4 ,dr4           
,patouillet has described the case of a 
family of nine  persons who were all    
driven mad by eating the root of the    
hyoscyamus  niger1 or black henbane4    
,one of them leapt into a pond1 another 
exclaimed that his neighbour would lose 
a cow in a month1 and a third           
vociferated that the crown piece of     

sixty pence would in a short time  rise 
to five livres4 ,on the following day   
they had all recovered their  senses1   
but recollected nothing of what had     
happened4 ,on the same day  they all saw
 objects double1 and1 what is still more
 remarkable1 on  the third day every    
object appeared to them as red as       
scarlet4 ,now  this red light was       
probably nothing more than the red      
phosphorescence  produced by the        
pressure of the blood-vessels on the    
retina1 and  analogous to the masses of 
blue1 green1 yellow1 and red light1     
which have been already mentioned as    
produced by a similar pressure in       
headaches1 arising from a disordered    
state of the digestive organs4    ,were 
we to analyse the various phenomena of  
spectral illusions1 we  should discover 
many circumstances favourable to these  
views4 ,in those  seen by ,nicolai1 the 
individual figures were always somewhat 
paler than  natural objects4 ,they      
sometimes grew more and more indistinct1

 and  became perfectly white2 and1 to   
use his own words1 8he could always     
distinguish with the greatest precision 
phantasms from phenomena40  ,nicolai    
sometimes saw the spectres when his eyes
 were shut1 and  sometimes they were    
thus made to disappear1--effects        
perfectly  identical with those which   
arise from the impressions of very      
luminous  objects4 ,sometimes the       
figures vanished entirely1 and at other 
times  only pieces of them disappeared1 
exactly conformable to what takes  place
 with objects seen by indirect vision1  
which most of those figures  must       
necessarily have been4    ,among the    
peculiarities of spectral illusions1    
there is one which  merits particular   
attention1 namely1 that they seem to    
cover or conceal  objects immediately   
beyond them4 ,it is this circumstance   
more than any  other which gives them   
the character of reality1 and at first  
sight it  seems difficult of            
explanation4 ,the distinctness of any   

impression on  the retina is entirely   
independent of the accommodation of the 
eye  to the distinct vision of external 
objects4 ,when the eye is at rest1  and 
is not accommodated to objects at any   
particular distance1 it is  in a state  
for seeing distant objects most         
perfectly4 ,when a distinct  spectral   
impression1 therefore1 is before it1 all
 other objects in its  vicinity will be 
seen indistinctly1 for while the eye is 
engrossed with  the vision1 it is not   
likely to accommodate itself to any     
other object  in the same direction4 ,it
 is quite common1 too1 for the eye to   
see only  one of two objects actually   
presented to it4 ,a sportsman who has   
been  in the practice of shooting with  
both his eyes open1 actually sees a     
double image of the muzzle of his       
fowling-piece1 though it is only  with  
one of these images that he covers his  
game1 having no perception  whatever of 
the other4 ,but there is still another  
principle upon which  only one of two   

objects may be seen at a time4 ,if we   
look very steadily  and continuously at 
a double pattern1 such as those on a    
carpet  composed of two single patterns 
of different colours1 suppose red and   
yellow2 and if we direct the mind       
particularly to the contemplation  of   
the red one1 the green pattern will     
sometimes vanish entirely1  leaving the 
red alone visible2 and by the same      
process the red one may  be made to     
disappear4 ,in this case1 however1 the  
two patterns1 like  the two images1 may 
be seen together2 but if the very same  
portion of  the retina is excited by the
 direct rays of an external object1 when
  it is excited by a mental impression1 
it can no more see them both  at the    
same time1 than a vibrating string can  
give out two different  fundamental     
sounds4 ,it is quite possible1 however1 
that the brightest  parts of a spectral 
figure may be distinctly seen along with
 the  brightest parts of an object      
immediately behind it1 but then the     

bright  parts of each object will fall  
upon different parts of the retina4     
,these views are illustrated by a case  
mentioned by ,dr4 ,abercrombie4 ,a      
gentleman1 who was a patient of his1 of 
an irritable habit1 and liable  to a    
variety of uneasy sensations in his     
head1 was sitting alone in his          
dining-room in the twilight1 when the   
door of the room was a little  open4 ,he
 saw distinctly a female figure enter1  
wrapped in a mantle1  with the face     
concealed by a large black bonnet4 ,she 
seemed to advance  a few steps towards  
him1 and then stop4 ,he had a full      
conviction that  the figure was an      
illusion of vision1 and he amused       
himself for some  time by watching it2  
at the same time observing that he could
 see  through the figure so as to       
perceive the lock of the door1 and other
  objects behind it4#f     #f ,inquiries
 concerning the ,intellectual ,powers1  
and the   ,investigation of ,truth4     
,edinburgh1 #ahcj4    ,if these views be

 correct1 the phenomena of spectral     
apparitions  are stripped of all their  
terror1 whether we view them in their   
supernatural character1 or as           
indications of bodily indisposition4    
,nicolai1 even1 in whose case they were 
accompanied with alarming  symptoms1    
derived pleasure from the contemplation 
of them1 and he  not only recovered from
 the complaint in which they originated1
 but  survived them for many            
years4--,mrs4 ,a41 too1 who sees them   
only at  distant intervals1 and with    
whom they have but a fleeting existence1
  will1 we trust1 soon lose her         
exclusive privilege1 when the slight    
indisposition which gives them birth has
 subsided4          ,,letter ,,iv4      
,science used as an instrument of       
imposture--,deceptions with plane   and 
concave mirrors practised by the        
ancients--,the magician's               
mirror--,effects of concave             
mirrors--,arial images--,images on      
smoke--,combination of mirrors for      

producing pictures from living          
objects--,the mysterious                
dagger--,ancient miracles with concave  
mirrors--,modern necromancy with them1  
as seen by ,cellini--,description   and 
effects of the magic                    
lantern--,improvements upon             
it--,phantasmagoric   exhibitions of    
,philipstall and others--,dr4 ,young's  
arrangement   of lenses1 c41 for the    
,phantasmagoria--,improvements          
suggested--,catadioptrical              
phantasmagoria for producing the        
pictures from living objects--,method of
 cutting off parts of the               
figures--,kircher's mysterious          
hand-writing on the wall--,his hollow   
cylindrical mirror for arial            
images--,cylindrical mirror for         
re-forming distorted pictures--,mirrors 
of variable curvature for   producing   
caricatures4      ,in the preceding     
observations man appears as the victim  
of his own  delusions--as the magician  
unable to exercise the spirits which he 

has himself called into being4 ,we shall
 now see him the dupe of  preconcerted  
imposture--the slave of his own         
ignorance--the prostrate  vassal of     
power and superstition4 ,i have already 
stated that the  monarchs and priests of
 ancient times carried on a systematic  
plan  of imposing upon their subjects--a
 mode of government which was in        
perfect accordance with their religious 
belief3 but it will scarcely be         
believed that the same delusions were   
practised after the establishment  of   
,christianity1 and that even the        
,catholic sanctuary was often the  seat 
of these unhallowed machinations4 ,nor  
was it merely the low and  cunning      
priest who thus sought to extort money  
and respect from the  most ignorant of  
his flock3 bishops and pontiffs         
themselves wielded  the magician's wand 
over the diadem of kings and emperors1  
and1 by  the pretended exhibition of    
supernatural power1 made the mightiest  
potentates of ,europe tremble upon their

 thrones4 ,it was the light of  science 
alone which dispelled this moral and    
intellectual darkness1  and it is       
entirely in consequence of its wide     
diffusion that we live  in times when   
sovereigns seek to reign only through   
the affections of  their people1 and    
when the minister of religion asks no   
other reverence  but that which is      
inspired by the sanctity of his office  
and the purity  of his character4    ,it
 was fortunate for the human race that  
the scanty knowledge of former  ages    
afforded so few elements of deception4  
,what a tremendous engine  would have   
been worked against our species by the  
varied and powerful  machinery of modern
 science6 ,man would still have worn the
 shackles  which it forged1 and his     
noble spirit would still have groaned   
beneath  its fatal pressure4    ,there  
can be little doubt that the most       
common1 as well as the most  successful1
 impositions of the ancients were of an 
optical nature1  and were practised by  

means of plane and concave mirrors4 ,it 
has been  clearly shown by various      
writers that the ancients made use of   
mirrors  of steel1 silver1 and a        
composition of copper and tin1 like     
those now  used for reflecting specula4 
,it is also very probable1 from a       
passage  in ,pliny1 that glass mirrors  
were made at ,sidon2 but it is evident1 
that1 unless the object presented to    
them was illuminated in a very  high    
degree1 the images which they formed    
must have been very faint and           
unsatisfactory4 ,the silver mirrors1    
therefore1 which were universally  used1
 and which are superior to those made of
 any other metal1 are  likely to have   
been most generally employed by the     
ancient magicians4  ,they were made to  
give multiplied and inverted images of  
objects1 that  is1 they were plane1     
polygonal or many-sided1 and concave4   
,there is  one property1 however1       
mentioned by ,aulus ,gellius1 which has 
given  unnecessary perplexity to        

commentators4 ,he states that there were
  specula1 which1 when put in a         
particular place1 gave no images of     
objects1 but when carried to another    
place1 recovered their property  of     
reflection4#g ,m4 ,salverte is of       
opinion that1 in quoting ,varro1  ,aulus
 ,gellius was not sufficiently          
acquainted with the subject1 and  erred 
in supposing that the phenomenon        
depended on the place instead  of the   
position of the mirror2 but this        
criticism is obviously made  with the   
view of supporting an opinion of his    
own--that the property  in question may 
be analogous to the phenomenon of       
polarised light1  which1 at a certain   
angle1 refuses to suffer reflexion from 
particular  bodies4 ,if this idea has   
any foundation1 the mirror must have    
been of  glass or some other body not   
metallic1 or1 to speak more correctly1  
there must have been two such mirrors1  
so nicely adjusted not only  to one     
another1 but to the light incident upon 

each1 that the effect  could not        
possibly be produced but by a           
philosopher thoroughly  acquainted with 
the modern discovery of the polarisation
 of light  by reflexion4 ,without       
seeking for so profound an explanation  
of the  phenomenon1 we may readily      
understand how a silver mirror may      
instantly  lose its reflecting power in 
a damp atmosphere1 in consequence of the
  precipitation of moisture upon its    
surface1 and may immediately recover  it
 when transported into drier air4     #g
 ,ut speculum in loco certo positum     
nihil imaginet2 aliorsum   translatum   
faciat imagines4 ,aul4 ,gel4 ,noct4     
,attic41 lib4 xvi41 cap4   #ah4         
,illustration3 ,fig4 #c4    ,one of the 
simplest instruments of optical         
deception is the plane  mirror1 and when
 two are combined for this purpose it   
has been called  the magician's mirror4 
,an observer in front of a plane mirror 
sees a  distinct image of himself2 but  
if two persons take up a mirror1 and  if

 the one person is as much to one side  
of a line perpendicular to  the middle  
of it as the other is to the other side1
 they will see each  other1 but not     
themselves4 ,if we now suppose ,,mc1    
,,cd1 ,,nc1 ,,cd to be the  partitions  
of two adjacent apartments let square   
openings be made in  the partitions at  
,a and ,b1 above five feet above the    
floor1 and let  them be filled with     
plate glass1 and surrounded with a      
picture frame1  so as to have the       
appearance of two mirrors4 ,place two   
mirrors1 ,e1 ,f1  one behind each       
opening at ,a and ,b1 inclined #de to   
the partition ,,mn1  and so large that a
 person looking into the plates of glass
 at ,a and  ,b will not see their edges4
 ,when this is done it is obvious that a
  person looking into the mirror ,a will
 not see himself1 but will see any      
person or figure placed at ,b4 ,if he   
believes that he is looking into a      
common mirror at ,a1 his astonishment   
will be great at seeing himself         

transformed into another person1 or into
 any living animal that may be  placed  
at ,b4 ,the success of this deception   
would be greatly increased  if a plane  
mirror1 suspended by a pulley1 could be 
brought immediately  behind the plane   
glass at ,a1 and drawn up from it at    
pleasure4 ,the  spectator at ,a1 having 
previously seen himself in this moveable
 mirror1  would be still more astonished
 when he afterwards perceived in the    
same  place a face different from his   
own4 ,by drawing the moveable mirror    
half up1 the spectator at ,a might see  
half of his own face joined to  half of 
the face placed at ,b2 but in the       
present day the most ignorant  persons  
are so familiar with the properties of a
 looking-glass1 that  it would be very  
difficult to employ this kind of        
deception with the  same success which  
must have attended it in a more         
illiterate age4 ,the  optical reader    
will easily see that the mirror ,f and  
the apartment ,,ncd  are not absolutely 

necessary for carrying on this          
deception2 for the  very same effects   
will be produced if the person at ,b is 
stationed at  ,g1 and looks towards the 
mirror ,f in the direction ,,gf4 ,as the
 mirror  ,f1 however1 must be placed as 
near to ,a as possible1 the person at ,g
  would be too near the partition ,,cn1 
unless the mirror ,f was extremely      
large4    ,the effect of this and every 
similar deception is greatly increased  
when the persons are illuminated with a 
strong light1 and the rest of  the      
apartment as dark as possible2 but      
whatever precautions are taken1  and    
however skilfully plane mirrors are     
combined1 it is not easy to  produce    
with them any very successful illusions4
    ,the concave mirror is the staple   
instrument of the magician's cabinet1   
and must always perform a principal part
 in all optical combinations4  ,in order
 to be quite perfect1 every concave     
mirror should have its  surface         
elliptical1 so that if any object is    

placed in one focus of the  ellipse1 an 
inverted image of it will be formed in  
the other focus4  ,this image1 to a     
spectator rightly placed1 appears       
suspended in the  air1 so that if the   
mirror and the object are hid from his  
view1 the  effect must appear to him    
almost supernatural4    ,the method of  
exhibiting the effect of concave mirrors
 most  advantageously is shown in ,fig4 
#d1 where ,,cd is the partition of a    
room having in it a square opening ,,ef1
 the centre of which is about  five feet
 above the floor4 ,this opening might be
 surrounded with a  picture-frame1 and a
 painting which exactly filled it might 
be so  connected with a pulley that it  
could be either slipped aside1 or       
raised so as to leave the frame empty4  
,a large concave mirror ,,mn is  then   
placed in another apartment1 so that    
when any object is placed at  ,a1 a     
distinct image of it may be formed in   
the centre of the opening  ,,ef4 ,let us
 suppose this object to be a plaster    

cast of any object made  as white as    
possible1 and placed in an inverted     
position at ,a4 ,a  strong light should 
then be thrown upon it by a powerful    
lamp1 the rays  of which are prevented  
from reaching the opening ,,ef4 ,when   
this is done1  a spectator placed at ,o 
will see an erect image of the statue at
 ,b1  the centre of the opening1        
standing in the air1 and differing from 
the  real statue only in being a little 
larger1 while the apparition will  be   
wholly invisible to other spectators    
placed at a little distance on  each    
side of him4    ,illustration3 ,fig4 #d4
    ,if the opening ,,ef is filled with 
smoke1 rising either from a             
chafing-dish1 in which incense is burnt1
 or made to issue in clouds  from some  
opening below1 the image will appear in 
the middle of the  smoke depicted upon  
it as upon a ground1 and capable of     
being seen by  those spectators who     
could not see the image of the air4 ,the
 rays of  light1 in place of proceeding 

without obstruction to an eye at ,o1 are
  reflected as it were from those minute
 particles of which the smoke  is       
composed1 in the same manner as a beam  
of light is rendered more  visible by   
passing through an apartment filled with
 dust or smoke4    ,it has long been a  
favourite experiment to place at ,a a   
white and  strongly illuminated human   
skull1 and to exhibit an image of it    
amid  the smoke of a chafing-dish at ,b2
 but a more terrific effect would be    
produced if a small skeleton suspended  
by invisible wires were placed  as an   
object at ,a4 ,its image suspended in   
the air at ,b1 or painted upon  smoke1  
could not fail to astonish the          
spectator4    ,the difficulty of placing
 a living person in an inverted         
position1  as an object at ,a1 has no   
doubt prevented the optical conjuror    
from  availing himself of so admirable a
 resource2 but this difficulty may be   
removed by employing a second concave   
mirror4 ,the second mirror may be  so   

placed as to reflect towards ,,mn the   
rays proceeding from an erect  living   
object1 and to form an inverted image of
 this object at ,a4 ,an  erect image of 
this inverted image will then be formed 
at ,b1 either  suspended in the air1 or 
depicted upon a wreath of smoke4 ,this  
arial  image will exhibit the precise   
form and colours and movements of the   
living object1 and it will maintain its 
character as an apparition if  any      
attempt is made by the spectator to     
grasp its unsubstantial fabric4    ,a   
deception of an alarming kind1 called   
the ,mysterious dagger1  has been long a
 favourite exhibition4 ,if a person with
 a drawn and  highly polished dagger1   
illuminated by a strong light1 stands a 
little farther from a concave mirror    
than its principal focus1 he  will      
perceive in the air between himself and 
the mirror an inverted  and diminished  
image of his own person1 with the dagger
 similarly  brandished4 ,if he aims the 
dagger at the centre of the mirrors     

concavity1 the two daggers will meet    
point to point1 and1 by pushing it      
still farther from him towards the      
mirror1 the imaginary dagger will       
strike at his heart4 ,in this case it is
 necessary that the direction of  the   
real dagger coincides with a diameter of
 the sphere of which the  mirror is a   
part2 but if its direction is on one    
side of that diameter1  the direction of
 the imaginary dagger will be as far on 
the other side  of the diameter1 and the
 latter will aim a blow at any person   
who is  placed in the proper position   
for receiving it4 ,if the person who    
bears  the real dagger is therefore     
placed behind a screen1 or otherwise    
concealed from the view of the          
spectator1 who is made to approach to   
the place of the image1 the thrust of   
the polished steel at his breast  will  
not fail to produce a powerful          
impression4 ,the effect of this         
experiment would no doubt be increased  
by covering with black cloth  the person

 who holds the dagger1 so that the image
 of his hand only  should be seen1 as   
the inverted picture of him would take  
away from the  reality of the           
appearance4 ,by using two mirrors1      
indeed1 this defect  might be remedied1 
and the spectator would witness an exact
 image of  the assassin aiming the      
dagger at his life4    ,the common way  
of making this experiment is to place a 
basket of fruit  above the dagger1 so   
that a distinct arial image of the fruit
 is  formed in the focus of the mirror4 
,the spectator1 having been desired  to 
take some fruit from the basket1        
approaches for that purpose1 while  a   
person properly concealed withdraws the 
real basket of fruit with one  hand1 and
 with the other advances the dagger1 the
 image of which being  no longer covered
 by the fruit1 strikes at the body of   
the astonished  spectator4    ,the      
powers of the concave mirror have been  
likewise displayed in  exhibiting the   
apparition of an absent or deceased     

friend4 ,for this  purpose1 a strongly  
illuminated bust or picture of the      
person is  placed before the concave    
mirror1 and a distinct image of the     
picture  will be seen either in the air 
or among smoke1 in the manner already   
described4 ,if the background of the    
picture is temporarily covered with     
lamp-black1 so that there is no light   
about the picture but what falls  upon  
the figure1 the effect will be more     
complete4    ,as in all experiments with
 concave mirrors1 the size of the arial 
image is to that of the real object as  
their distances from the mirror1  we    
may1 by varying the distance of the     
object1 increase or diminish the  size  
of the image4 ,in doing this1 however1  
the distance of the image  from the     
mirror is at the same time changed1 so  
that it would quit the  place most      
suitable for its exhibition4 ,this      
defect may be removed by  simultaneously
 changing the place both of the mirror  
and the object1 so  that the image may  

remain stationary1 expanding itself from
 a luminous  spot to a gigantic size1   
and again passing through all           
intermediate  magnitudes1 till it       
vanishes in a cloud of light4    ,those 
who have studied the effects of concave 
mirrors of a small  size1 and without   
the precautions necessary to ensure     
deception1  cannot form any idea of the 
magical effect produced by this class of
  optical apparitions4 ,when the        
instruments of illusion are themselves  
concealed1--when all extraneous lights  
but those which illuminate  the real    
object are excluded1--when the mirrors  
are large and  well-polished1 and truly 
formed1--the effect of the              
representation on  ignorant minds is    
altogether overpowering2 while even     
those who know  the deception1 and      
perfectly understand its principles1 are
 not a  little surprised at its effects4
 ,the inferiority in the effects of a   
common concave mirror to that of a      
well-arranged exhibition is greater     

even than that of a perspective picture1
 hanging in an apartment1 to  the same  
picture exhibited under all the imposing
 accompaniments of a  dioramic          
representation4    ,it can scarcely be  
doubted1 that a concave mirror was the  
principal  instrument by which the      
heathen gods were made to appear in the 
ancient  temples4 ,in the imperfect     
accounts which have reached us of these 
apparitions1 we can trace all the       
elements of an optical illusion4 ,in    
the ancient temple of ,hercules at      
,tyre1 ,pliny mentions that there was  a
 seat made of a consecrated stone1 8from
 which the gods easily rose40           
,esculapius often exhibited himself to  
his worshippers in his temple  at       
,tarsus2 and the temple of ,enguinum in 
,sicily was celebrated as the  place    
where the goddesses exhibited themselves
 to mortals4 ,iamblichus  actually      
informs us1 that the ancient magicians  
caused the gods to  appear among the    
vapours disengaged from fire2 and when  

the conjuror  ,maximus terrified his    
audience by making the statue of ,hecate
 laugh1  while in the middle of the     
smoke of burning incense1 he was        
obviously  dealing with the image of a  
living object dressed in the costume of 
the  sorceress4    ,the character of    
these exhibitions in the ancient temples
 is so  admirably depicted in the       
following passage of ,damascius1 quoted 
by ,m4  ,salverte1 that we recognise all
 the optical effects which have been    
already described4 8,in a               
manifestation10 says he1 8which ought   
not to  be revealed 444 there appeared  
on the wall of the temple a mass of     
light1 which at first seemed to be very 
remote2 it transformed itself1  in      
coming nearer1 into a face evidently    
divine and supernatural1 of  a severe   
aspect1 but mixed with gentleness1 and  
extremely beautiful4  ,according to the 
institutions of a mysterious religion1  
the  ,alexandrians honoured it as       
,osiris and ,adonis40    ,among more    

modern examples of this illusion1 we may
 mention the case of  the ,emperor      
,basil of ,macedonia4 ,inconsolable at  
the loss of his son1  this sovereign had
 recourse to the prayers of the ,pontiff
 ,theodore  ,santabaren1 who was        
celebrated for his power of working     
miracles4 ,the  ecclesiastical conjuror 
exhibited to him the image of his       
beloved  son1 magnificently dressed and 
mounted upon a superb charger3 the      
youth rushed towards his father1 threw  
himself into his arms1 and  disappeared4
 ,m4 ,salverte judiciously observes1    
that this deception  could not have been
 performed by a real person who imitated
 the figure  of the young prince4 ,the  
existence of this person1 betrayed by so
  remarkable a resemblance1 and by the  
trick of the exhibition1 could not  fail
 to have been discovered and denounced1 
even if we could explain  how the son   
could be so instantaneously disentangled
 from his father's  embrace4 ,the       
emperor1 in short1 saw the arial image  

of a picture  of his son on horseback2  
and as the picture was brought nearer   
the  mirror1 the image advanced into his
 arms1 when it of course eluded his     
affectionate grasp4    ,these and other 
allusions to the operations of the      
ancient magic1  though sufficiently     
indicative of the methods which were    
employed1 are  too meagre to convey any 
idea of the splendid and imposing       
exhibitions  which must have been       
displayed4 ,a national system of        
deception1  intended as an instrument of
 government1 must have brought into     
requisition not merely the scientific   
skill of the age1 but a variety  of     
subsidiary contrivances calculated to   
astonish the beholder1 to  confound his 
judgment1 to dazzle his senses1 and to  
give a predominant  influence to the    
peculiar imposture which it was thought 
desirable  to establish4 ,the grandeur  
of the means may be inferred from their 
efficacy1 and from the extent of their  
influence4    ,this defect1 however1 is1

 to a certain degree1 supplied by an    
account  of a modern necromancy1 which  
has been left us by the celebrated      
,benvenuto ,cellini1 and in which he    
himself performed an active part4       
8,it happened10 says he1 8through a     
variety of odd accidents1 that ,i  made 
acquaintance with a ,sicilian priest1   
who was a man of genius1 and  well      
versed in the ,latin and ,greek authors4
 ,happening one day to have  some       
conversation with him when the subject  
turned upon the art of  necromancy1 ,i1 
who had a great desire to know something
 of the matter1  told him1 that ,i had  
all my life felt a curiosity to be      
acquainted with  the mysteries of this  
art4    8,the priest made answer1 #8that
 the man must be of a resolute and      
steady temper who enters upon that      
study4' ,i replied1 #8that ,i had       
fortitude and resolution enough1 if ,i  
could but find an opportunity4'  ,the   
priest subjoined1 #8,if you think you   
have the heart to venture1 ,i  will give

 you all the satisfaction you can       
desire4' ,thus we agreed  to enter upon 
a plan of necromancy4 ,the priest one   
evening prepared  to satisfy me1 and    
desired me to look out for a companion  
or two4 ,i  invited one ,vincenzio      
,romoli1 who was my intimate            
acquaintance3 he  brought with him a    
native of ,pistoia1 who cultivated the  
black art  himself4 ,we repaired to the 
,colosseo1 and the priest1 according to 
the  custom of necromancers1 began to   
draw circles upon the ground1 with  the 
most impressive ceremonies imaginable3  
he likewise brought hither  asaftida1   
several precious perfumes1 and fire1    
with some compositions  also1 which     
diffused noisome odours4 ,as soon as he 
was in readiness1  he made an opening to
 the circle1 and having taken us by the 
hand1  ordered the other necromancer1   
his partner1 to throw the perfumes  into
 the fire at a proper time1 entrusting  
the care of the fire and  perfumes to   
the rest2 and thus he began his         

incantations4 ,this ceremony  lasted    
above an hour and a half1 when there    
appeared several legions  of devils1    
insomuch that the amphitheatre was quite
 filled with them4  ,i was busy about   
the perfumes1 when the priest1          
perceiving there was  a considerable    
number of infernal spirits1 turned to me
 and said1  #8,benvenuto1 ask them      
something4' ,i answered1 #8,let them    
bring me into  the company of my        
,sicilian mistress ,angelica4' ,that    
night he obtained  no answer of any     
sort2 but ,i had received great         
satisfaction in having  my curiosity so 
far indulged4 ,the necromancer told me  
it was requisite  we should go a second 
time1 assuring me that ,i should be     
satisfied in  whatever ,i asked2 but    
that ,i must bring with me a pure1      
immaculate boy4    8,i took with me a   
youth who was in my service1 of about   
twelve years of  age1 together with the 
same ,vincenzio ,romoli1 who had been my
 companion  the first time1 and one     

,agnolino ,gaddi1 an intimate           
acquaintance1 whom  ,i likewise         
prevailed on to assist at the ceremony4 
,when we came to the  place appointed1  
the priest having made his preparations 
as before1  with the same and even more 
striking ceremonies1 placed us within   
the  circle1 which he had likewise drawn
 with a more wonderful art and in a     
more solemn manner than at our former   
meeting4 ,thus1 having committed  the   
care of the perfumes and the fire to my 
friend ,vincenzio1 who was  assisted by 
,agnolino ,gaddi1 he put into my hand a 
pintaculo or magical  chart1 and bid me 
turn it towards the places that he      
should direct me2  and under the        
pintaculo ,i held the boy4 ,the         
necromancer1 having begun  to make his  
tremendous invocations1 called by their 
names a multitude  of demons who were   
the leaders of the several legions1 and 
questioned  them1 by the power of the   
eternal uncreated ,god1 who lives for   
ever1  in the ,hebrew language1 as      

likewise in ,latin and ,greek2 insomuch 
that  the amphitheatre was almost in an 
instant filled with demons more         
numerous than at the former conjuration4
 ,vincenzio ,romoli was busied  in      
making a fire1 with the assistance of   
,agnolino1 and burning a great  quantity
 of precious perfumes4 ,i1 by the       
directions of the necromancer1  again   
desired to be in the company of my      
,angelica4 ,the former thereupon        
turning to me said1--',know1 they have  
declared that1 in the space of a  month1
 you shall be in her company4'    8,he  
thus requested me to stand resolutely by
 him1 because the legions  were now     
above a thousand more in number than he 
had designed2 and  besides1 these were  
the most dangerous2 so that1 after they 
had  answered my question1 it behoved   
him to be civil to them1 and dismiss    
them quietly4 ,at the same time the boy 
under the pintaculo was in a  terrible  
fright1 saying1 that there were in that 
place a million of  fierce men1 who     

threatened to destroy us2 and that1     
moreover1 four  armed giants of enormous
 stature were endeavouring to break into
 our  circle4 ,during this time1 whilst 
the necromancer1 trembling with fear1   
endeavoured by mild and gentle methods  
to dismiss them in the best way  he     
could1 ,vincenzio ,romoli1 who quivered 
like an aspen leaf1 took care  of the   
perfumes4 ,though ,i was as much        
terrified as any of them1 ,i did  my    
utmost to conceal the terror ,i felt2 so
 that ,i greatly contributed  to inspire
 the rest with resolution2 but the truth
 is1 ,i gave myself  over for a dead    
man1 seeing the horrid fright the       
necromancer was in4  ,the boy placed his
 head between his knees and said1 #8,in 
this posture  will ,i die2 for we shall 
all surely perish4' ,i told him that all
 these  demons were under us1 and what  
he saw was smoke and shadow2 so bid  him
 hold up his head and take courage4 ,no 
sooner did he look up than  he cried    
out1 #8,the whole amphitheatre is       

burning1 and the fire is  just falling  
upon us4' ,so covering his eyes with his
 hands1 he again  exclaimed1 #8that     
destruction was inevitable1 and desired 
to see no  more4' ,the necromancer      
entreated me to have a good heart1 and  
take  care to burn proper perfumes2 upon
 which ,i turned to ,romoli1 and bid    
him burn all the most precious perfumes 
he had4 ,at the same time ,i  cast my   
eye upon ,agnolino ,gaddi1 who was      
terrified to such a degree  that he     
could scarce distinguish objects1 and   
seemed to be half dead4  ,seeing him in 
this condition1 ,i said1 #8,agnolino1   
upon these occasions  a man should not  
yield to fear1 but should stir about and
 give his  assistance1 so come directly 
and put on some more of these4' ,the    
effects of poor ,agnolino's fear were   
overpowering4 ,the boy1 hearing  a      
crepitation1 ventured once more to raise
 his head1 when1 seeing me  laugh1 he   
began to take courage1 and said #8that  
the devils were flying  away with a     

vengeance4'    8,in this condition we   
stayed1 till the bell rang for morning  
prayers4  ,the boy again told us1 that  
there remained but few devils1 and these
  were at a great distance4 ,when the   
magician had performed the rest of  his 
ceremonies1 he stripped off his gown1   
and took up a wallet full of  books     
which he had brought with him4    8,we  
all went out of the circle together1    
keeping as close to each other  as we   
possibly could1 especially the boy1 who 
had placed himself in  the middle1      
holding the necromancer by the coat1 and
 me by the cloak4  ,as we were going to 
our houses in the quarter of ,banchi1   
the boy told  us that two of the demons 
whom we had seen at the amphitheatre    
went on  before us leaping and skipping1
 sometimes running upon the roofs of the
  houses1 and sometimes upon the ground4
 ,the priest declared1 that though  he  
had often entered magic circles1 nothing
 so extraordinary had ever  happened to 
him4 ,as we went along1 he would fain   

persuade me to assist  with him at      
consecrating a brook1 from which1 he    
said1 we should derive  immense riches2 
we should then ask the demons to        
discover to us the  various treasures   
with which the earth abounds1 which     
would raise us to  opulence and power2  
but that these love-affairs were mere   
follies1 from  whence no good could be  
expected4 ,i answered1 #8that ,i would  
readily  have accepted his proposal1 if 
,i understood ,latin4' ,he redoubled his
  persuasions1 assuring me1 that the    
knowledge of the ,latin language  was by
 no means material4 ,he added1 that he  
could have ,latin scholars  enough1 if  
he had thought it worth while to look   
out for them1 but that  he could never  
have met with a partner of resolution   
and intrepidity  equal to mine1 and that
 ,i should by all means follow his      
advice4 ,whilst  we were engaged in this
 conversation we arrived at our         
respective  houses1 and all that night  
dreamt of nothing but devils40    ,it is

 impossible to peruse the preceding     
description without being  satisfied    
that the legions of devils were not     
produced by any influence  upon the     
imaginations of the spectators1 but were
 actual optical  phantasms1 or the      
images of pictures or objects produced  
by one or  more concave mirrors or      
lenses4 ,a fire is lighted1 and perfumes
 and  incense are burnt1 in order to    
create a ground for the images1 and the 
beholders are rigidly confined within   
the pale of the magic circle4 ,the      
concave mirror and the objects presented
 to it having been so placed  that the  
persons within the circle could not see 
the arial image of  the objects by the  
rays deeply reflected from the mirror1  
the work of  deception was ready to     
begin4 ,the attendance of the magician  
upon his  mirror was by no means        
necessary4 ,he took his place along with
 the  spectators within the magic       
circle4 ,the images of the devils were  
all  distinctly formed in the air       

immediately above the fire1 but none of 
them could be seen by those within the  
circle4 ,the moment1 however1  that     
perfumes were thrown into the fire to   
produce smoke1 the first  wreath of     
smoke that rose through the place of one
 or more of the  images1 would reflect  
them to the eyes of the spectator1 and  
they could  again disappear if the      
wreath was not followed by another4     
,more and  more images would be rendered
 visible as new wreaths of smoke arose1 
and the whole group would appear at once
 when the smoke was uniformly  diffused 
over the place occupied by the images4  
,the 8compositions which diffused       
noisome odours0 were intended to        
intoxicate or stupify the spectators1 so
 as to increase their liability  to     
deception1 or to add to the real        
phantasms which were before their  eyes1
 others which were the offspring only of
 their own imaginations4  ,it is not    
easy to gather from the description what
 parts of the  exhibition were actually 

presented to the eyes of the spectators1
 and  what parts of it were imagined by 
themselves4 ,it is quite evident  that  
the boy1 as well as ,agnolino ,gaddi1   
were so overpowered with  terror that   
they fancied many things which they did 
not see2 but when  the boy declares that
 four armed giants1 of an enormous      
stature1 were  threatening to break into
 the circle1 he gives an accurate       
description  of the effect that would be
 produced by pushing the figures nearer 
the  mirror1 and then magnifying their  
images1 and causing them to advance     
towards the circle4 ,although ,cellini  
declares that he was trembling  with    
fear1 yet it is quite evident that he   
was not entirely ignorant of  the       
machinery which was at work2 for in     
order to encourage the boy1 who  was    
almost dead with fear1 he assured them  
that the devils were under  their power1
 and that 8what he saw was smoke and    
shadow40    ,mr4 ,roscoe1 from whose    
,life of ,cellini the preceding         

description is  taken1 draws a similar  
conclusion from the consolatory words   
addressed  to the boy1 and states that  
they 8confirm him in the belief1 that   
the  whole of these appearances1 like a 
phantasmagoria1 were merely the  effects
 of a magic lantern produced on volumes 
of smoke from various  kinds of burning 
wood40 ,in drawing this conclusion1 ,mr4
 ,roscoe has  not adverted to the fact1 
that this exhibition took place about   
the  middle of the #afth century1 while 
the magic lantern was not invented  by  
,kircher till towards the middle of the 
#agth century2 ,cellini  having died in 
#aegj1 and ,kircher having been born in 
#afja4 ,there  is no doubt that the     
effects described could be produced by  
this  instrument1 but we are not        
entitled to have recourse to any other  
means of explanation but those which    
were known to exist at the time  of     
,cellini4 ,if we suppose1 however1 that 
the necromancer either had a  regular   
magic lantern1 or that he had fitted up 

his concave mirror in  a box containing 
the figures of his devils1 and that this
 box with its  lights was carried home  
with the party1 we can easily account   
for the  declaration of the boy1 8that  
as they were going home to their houses 
in the quarter of ,banchi1 two of the   
demons whom we had seen at the          
amphitheatre went on before us leaping  
and skipping1 sometimes running  upon   
the roofs of the houses1 and sometimes  
upon the ground40    ,the introduction  
of the magic lantern as an optical      
instrument  supplied the magicians of   
the #agth century with one of their most
  valuable tools4 ,the use of the       
concave mirror1 which does not appear   
to have been even put up into the form  
of an instrument1 required a  separate  
apartment1 or at least that degree of   
concealment which it  was difficult on  
ordinary occasions to command2 but the  
magic lantern1  containing in a small   
compass its lamp1 its lenses1 and its   
sliding  figures1 was peculiarly fitted 

for the itinerant conjuror1 who had     
neither the means of providing a less   
portable and more extensive  apparatus1 
nor the power of transporting and       
erecting it4    ,the magic lantern shown
 in the annexed figure consists of a    
dark  lantern1 ,,ab1 containing a lamp  
,g1 and a concave metallic mirror1 ,,mn1
  and it is so constructed that when the
 lamp is lighted not a ray of  light is 
able to escape from it4 ,into the side  
of the lantern is fitted  a double tube1
 ,,cd1 the outer half of which ,d is    
capable of moving  within the other     
half4 ,a large plano-convex lens ,c1 is 
fixed at the  inner end of the double   
tube1 and a small convex lens ,d1 at the
 outer  end2 and to the fixed tube ,,ce1
 there is joined a groove ,,ef1 in which
  the sliders containing the painted    
objects are placed1 and through  which  
they can be moved4 ,each slider contains
 a series of figures or  pictures       
painted on glass with highly transparent
 colours4 ,the direct  light of the lamp

 ,g1 and the light reflected from the   
mirror ,,mn1  falling upon the          
illuminating lens ,c1 is concentrated by
 it so as to  throw a brilliant light   
upon the painting on the slider1 and as 
this  painting is in the conjugate focus
 of the convex lens ,d1 a magnified     
image of it will be formed on a white   
wall or white cloth placed at ,,pq4  ,if
 the lens ,d is brought nearer to ,,ef1 
or to the picture1 the distinct  image  
will be more magnified1 and will be     
formed at a greater distance  from ,d1  
so that if there is any particular      
distance of the image which  is more    
convenient than another1 or any         
particular size of the object  which we 
wish1 it can be obtained by varying the 
distance of the lens  ,d from ,,ef4     
,illustration3 ,fig4 #e4    ,when the   
image is received on an opaque ground1  
as is commonly the  case1 the spectators
 are placed in the same room with the   
lantern2  but1 for the purposes of      
deception1 it would be necessary to     

place  the lantern in another apartment 
like the mirror in ,fig4 #d1 and to     
throw the magnified pictures on a large 
plate of ground glass1 or a  transparent
 gauze screen1 stretched across an      
opening ,,ef1 ,fig4 #d1 made  in the    
partition which separates the spectators
 from the exhibitor4  ,the images might1
 like those of the concave mirror1 be   
received upon  wreaths of smoke4 ,these 
images are of course always inverted in 
reference to the position of the painted
 objects2 but in order to  render them  
really erect1 we have only to invert the
 sliders4 ,the  representations of the  
magic lantern never fail to excite a    
high degree  of interest1 even when     
exhibited with the ordinary apparatus2  
but  by using double sliders1 and       
varying their movements1 very striking  
effects may be produced4 ,a smith1 for  
example1 is made to hammer  upon his    
anvil1--a figure is thrown into the     
attitude of terror by  the introduction 
of a spectral apparition1 and a tempest 

at sea is  imitated1 by having the sea  
on one slider1 and the ships on other   
sliders1 to which an undulatory motion  
is communicated4    ,the magic lantern  
is susceptible of great improvement in  
the painting  of the figures1 and in the
 mechanism and combination of the       
sliders4  ,a painted figure1 which      
appears well executed to the unassisted 
eye1  becomes a mere daub when magnified
 #ej or #ajj times2 and when we         
consider what kind of artists are       
employed in their execution1 we need    
not wonder that this optical instrument 
has degenerated into a mere  toy for the
 amusement of the young4 ,unless for    
public exhibition1  the expense of      
exceedingly minute and spirited drawings
 could not be  afforded2 but ,i have no 
doubt that if such drawings were        
executed1 a  great part of the expense  
might be saved by engraving them on     
wood1 and  transferring their outline to
 the glass sliders4    ,a series of     
curious representations might be        

effected1 by inserting  glass plates    
containing suitable figures in a trough 
having two of its  sides parallel1 and  
made of plate glass4 ,the trough must be
 introduced  at ,,ef1 so that the figure
 on the glass is at the proper distance 
from  the object lens ,d4 ,when the     
trough is filled with water1 or with    
any transparent fluid1 the picture at   
,,pq will be seen with the same         
distinctness as if the figure had been  
introduced by itself into the  groove   
,,ef2 but if any transparent fluid of a 
different density from  water is mixed  
with it1 so as to combine with it       
quickly or slowly1 the  appearance of   
the figure displayed at ,,pq will       
undergo singular changes4  ,if spirits  
of wine1 or any ardent spirit1 are mixed
 with the water1 so  as to produce      
throughout its mass partial variations  
of density1 the  figure at ,,pq1 will be
 as it were broken down into a thousand 
parts1  and will recover its continuity 
and distinctness when the two fluids    

have combined4 ,if a fluid of less      
density than water is laid gently  upon 
the water1 so as to mix with it         
gradually1 and produce a regular        
diminution of density downwards--or if  
saline substances1 soluble in  water1   
are laid at the bottom of the trough1   
the density will diminish  upwards1 and 
the figure will undergo the most curious
 elongations and  contractions4         
,analogous effects may be produced by   
the application of  heat to the surface 
or sides of the trough1 so that we may  
effect at  the same time both an        
increase and a diminution in the density
 of the  water1 in consequence of which 
the magnified images will undergo the   
most remarkable transformations4 ,it is 
not necessary to place the glass  plate 
which contains the figure within the    
trough4 ,it may be placed in  front of  
it1 and by thus creating as it were an  
atmosphere with local  variations of    
density1 we may exhibit the phenomena of
 the mirage and  of looming1 in which   

the inverted images of ships and other  
objects are  seen in the air1 as        
described in another letter4    ,the    
power of the magic lantern has been     
greatly extended by placing  it on one  
side of the transparent screen of       
taffeta which receives  the images1     
while the spectators are placed on the  
other side1 and  by making every part of
 the glass sliders opaque1 excepting the
 part  which forms the figures4 ,hence  
all the figures appear luminous on a    
black ground1 and produce a much greater
 effect with the same degree of         
illumination4 ,an exhibition depending  
on these principles was brought  out by 
,m4 ,philipstall in #ahjb1 under the    
name of the ,phantasmagoria1  and when  
it was shown in ,london and ,edinburgh1 
it produced the most  impressive effects
 upon the spectators4 ,the small theatre
 of exhibition  was lighted only by one 
hanging lamp1 the flame of which was    
drawn up  into an opaque chimney or     
shade when the performance began4 ,in   

this  8darkness visible0 the curtain    
rose and displayed a cave with skeletons
  and other terrific figures in relief  
upon its walls4 ,the flickering  light  
was then drawn up beneath its shroud1   
and the spectators in total  darkness   
found themselves in the middle of       
thunder and lightning4  ,a thin         
transparent screen had1 unknown to the  
spectators1 been let  down after the    
disappearance of the light1 and upon it 
the flashes of  lightning and all the   
subsequent appearances were represented4
 ,this  screen being half-way between   
the spectators and the cave which was   
first shown1 and being itself invisible1
 prevented the observers from  having   
any idea of the real distance of the    
figures1 and gave them the  entire      
character of arial pictures4 ,the       
thunder and lightning were  followed by 
the figures of ghosts1 skeletons1 and   
known individuals1  whose eyes and mouth
 were made to move by the shifting of   
combined  sliders4 ,after the first     

figure had been exhibited for a short   
time1  it began to grow less and less1  
as if removed to a great distance1 and  
at last vanished in a small cloud of    
light4 ,out of this same cloud the  germ
 of another figure began to appear1 and 
gradually grew larger and  larger1 and  
approached the spectators1 till it      
attained its perfect  development4 ,in  
this manner the head of ,dr4 ,franklin  
was transformed  into a skull2 figures  
which retired with the freshness of life
 came  back in the form of skeletons1   
and the retiring skeletons returned in  
the drapery of flesh and blood4    ,the 
exhibition of these transmutations was  
followed by spectres1  skeletons1 and   
terrific figures1 which1 instead of     
receding and  vanishing as before1      
suddenly advanced upon the spectators1  
becoming  larger as they approached     
them1 and finally vanished by appearing 
to  sink into the ground4 ,the effect of
 this part of the exhibition was        
naturally the most impressive4 ,the     

spectators were not only surprised  but 
agitated1 and many of them were of      
opinion that they could have  touched   
the figures4 ,m4 ,robertson1 at ,paris1 
introduced along with his  pictures the 
direct shadows of living objects1 which 
imitated coarsely  the appearance of    
those objects in a dark night or in     
moonlight4    ,all these phenomena were 
produced by varying the distance of the 
magic  lantern ,,ab1 ,fig #e1 from the  
screen ,,pq1 which remained fixed1 and  
at the  same time keeping the image upon
 the screen distinct1 by increasing  the
 distance of the lens ,d from the       
sliders in ,,ef4 ,when the lantern      
approached to ,,pq1 the circle of light 
,,pq1 or the section of the cone  of    
rays ,,pdq1 gradually diminished1 and   
resembled a small bright cloud1  when ,d
 was close to the screen4 ,at this time 
a new figure was put  in1 so that when  
the lantern receded from the screen1 the
 old figure  seemed to have been        
transformed into the new one4 ,although 

the figure  was always at the same      
distance from the spectators1 yet1 owing
 to its  gradual diminution in size1 it 
necessarily appeared to be retiring to  
a distance4 ,when the magic lantern was 
withdrawn from ,,pq1 and the lens  ,d at
 the same time brought nearer to ,,ef1  
the image in ,,pq gradually  increased  
in size1 and therefore seemed in the    
same proportion to be  approaching the  
spectators4    ,superior as this        
exhibition was to any representation    
that had been  previously made by the   
magic lantern1 it still laboured under  
several  imperfections4 ,the figures    
were poorly drawn1 and in other respects
 not  well executed1 and no attempt     
whatever was made to remove the optical 
incongruity of the figures becoming more
 luminous when they retired  from the   
observer1 and more obscure when they    
approached to him4 ,the  variation of   
the distance of the lens ,d from the    
sliders in ,,ef was not  exactly adapted
 to the motion of the lantern to and    

from the screen1 so  that the outline of
 the figures was not equally distinct   
during their  variations of magnitude4  
,dr4 ,thomas ,young suggested the       
arrangement shown in ,fig4 #f for       
exhibiting the phantasmagoria4          
,illustration3 ,fig4 #f4    ,the magic  
lantern is mounted on a small car ,h1   
which runs on wheels  ,,ww4 ,the direct 
light of the lamp ,g1 and that reflected
 from the mirror  ,m1 is condensed by   
the illuminating lenses ,,cc1 upon the  
transparent  figures in the opaque      
sliders at ,e1 and the image of these   
figures is  formed at ,,pq1 by the      
object lens ,d4 ,when the car ,h is     
drawn back on  its wheels1 the rod ,,ik 
brings down the point ,k1 and by means  
of the rod  ,,kl1 pushes the lens ,d    
nearer to the sliders in ,,ef1 and when 
the car  advances to ,,pq1 the point ,k 
is raised1 and the rod ,,kl draws out   
the  lens ,d from the slider1 so that   
the image is always in the conjugate    
focus of ,d1 and therefore distinctly   

painted on the screen4 ,the rod ,,kn    
must be equal in length to ,,ik1 and the
 point ,i must be twice the focal       
length of the lens ,d before the object1
 ,l being immediately under the  focus  
of the lens4 ,in order to diminish the  
brightness of the image  when it grows  
small and appears remote1 ,dr4 ,young   
contrived that the  support of the lens 
,d should suffer a screen ,s to fall and
 intercept a  part of the light4 ,this  
method1 however1 has many disadvantages1
 and we  are satisfied1 that the only   
way of producing a variation in the     
light  corresponding to the variation in
 the size of the image1 is to use a     
single illuminating lens ,c1 and to     
cause it to approach ,,ef1 and throw    
less light upon the figures when ,d is  
removed from ,,ef1 and to make ,c       
recede from ,,ef when ,d approaches to  
it4 ,the lens ,c should therefore  be   
placed in a mean position1 corresponding
 to a mean distance of the  screen1 and 
to the ordinary size of the figures1 and

 should have the  power of being removed
 from the slider ,,ef1 when a greater   
intensity of  light is required for the 
images when they are rendered gigantic1 
and  of being brought close to ,,ef when
 the images are made small4 ,the size   
of the lens ,c ought of course to be    
such that the section of its cone  of   
rays at ,,ef is equal to the size of the
 figure on the slider when ,c  is at its
 greatest distance from the slider4     
,the method recommended by ,dr4 ,young  
for pulling out and pushing in  the     
object lens ,d1 according as the lantern
 approaches to or recedes  from the     
screen1 is very ingenious and effective4
 ,it is1 however1  clumsy in itself1 and
 the connexion of the levers with the   
screen1  and their interposition between
 it and the lantern1 must interfere     
with the operations of the exhibitor4   
,it is1 besides1 suited only to  short  
distances between the screen and the    
lantern2 for when that  distance is     
considerable1 as it must sometimes      

require to be1 the  levers ,,kl1 ,,ki1  
,,kt1 would bend by the least strain1   
and become unfitted  for their purpose4 
,for these reasons the mechanism which  
adjusts the  lens ,d should be moved by 
the axle of the front wheels1 the tube  
which  contains the lens should be kept 
at its greatest distance from ,,ef by  a
 slender spring1 and should be pressed  
to its proper distance by the  action of
 a spiral cam suited to the optical     
relation between the two  conjugate     
focal distances of the lens4            
,superior as the representations of the 
phantasmagoria are to those of  the     
magic lantern1 they are still liable to 
the defect which we have  mentioned1    
namely1 the necessary imperfection of   
the minute transparent  figures when    
magnified4 ,this defect cannot be       
remedied by employing  the most skilful 
artists4 ,even ,michael ,angelo would   
have failed in  executing a figure an   
inch long with transparent varnishes1   
when all  its imperfections were to be  

magnified4 ,in order1 therefore1 to     
perfect  the art of representing        
phantasms1 the objects must be living   
ones1 and  in place of chalky ill-drawn 
figures1 mimicking humanity by the most 
absurd gesticulations1 we shall have    
phantasms of the most perfect           
delineation1 clothed in real drapery1   
and displaying all the movements  of    
life4 ,the apparatus by which such      
objects may be used1 may be called  the 
catadioptrical phantasmagoria1 as it    
operates both by reflexion  and         
refraction4    ,illustration3 ,fig4 #g4 
,the combination of mirrors and lenses  
which seems best adapted for this       
purpose is shown in ,fig4 #g1 where ,,ab
 is a living figure placed before  a    
large concave mirror ,,mn1 by means of  
which a diminished and inverted  image  
of it is formed at ab4 ,if ,,pq is the  
transparent screen upon  which the image
 is to be shown to the spectators on the
 right hand of  it1 a large lens ,,ll   
must be so placed before the image ab1  

as to  form a distinct and erect picture
 of it at ,a,b upon the screen4 ,when   
the image ,a,b is required to be the    
exact size of ,,ab1 the lens ,,ll  must 
magnify the small image ab as much as   
the mirror ,,mn diminishes  the figure  
,,ab4 ,the living object ,,ab1 the      
mirror ,,mn1 and the lens ,,ll1  must   
all be placed in a moveable car for the 
purpose of producing the  variations in 
the size of the phantasms1 and the      
transformations of  one figure into     
another4 ,the contrivance for adjusting 
the lens ,,ll1 to  give a distinct      
picture at different distances of the   
screen1 will1 of  course1 be required in
 the present apparatus4 ,in order to    
give full  effect to the phantasms1 the 
living objects at ,,ab will require to  
be  illuminated in the strongest manner1
 and should always be dressed  either in
 white or in very luminous colours2 and1
 in order to give them  relief1 a black 
cloth should be stretched at some       
distance behind them4  ,many interesting

 effects might also be produced by      
introducing at ,,ab  fine paintings and 
busts4    ,it would lead us into too    
wide a field were we to detail the      
immense  variety of resources which the 
science of optics furnishes for such    
exhibitions4 ,one of these1 however1 is 
too useful to be passed without  notice4
 ,if we interpose a prism with a small  
refracting angle between  the image ab1 
,fig4 #g1 and the lens ,,ll1 the part of
 the figure  immediately opposite to the
 prism will be as it were detached from 
the figure1 and will be exhibited       
separately on the screen ,,pq4 ,let us  
suppose that this part is the head of   
the figure4 ,it may be detached         
vertically1 or lifted from the body as  
if it were cut off1 or it may  be       
detached downwards and placed on the    
breast as if the figure were  deformed4 
,in detaching the head vertically or    
laterally1 an opaque  screen must be    
applied to prevent any part of the head 
from being  seen by rays which do not   

pass through the prism2 but this and    
other  practical details will soon occur
 to those who put the method to an      
experimental trial4 ,the application of 
the prism is shown in ,fig4 #h1  where  
ab is the inverted image formed by a    
concave mirror1 ,,abc a  prism with a   
small refracting angle ,,bca1 placed    
between ab and the  lens ,,ll1 s a small
 opaque screen1 and ,,ab the figure with
 its head  detached4 ,a hand may be made
 to grasp the hair of the head1 and the 
aspect of death may be given to it1 as  
if it had been newly cut off4  ,such a  
representation could be easily made1 and
 the effect upon the  spectators would  
be quite overpowering4 ,the lifeless    
head might then be  made to recover its 
vitality1 and be safely replaced upon   
the figure4  ,if the head ,a of the     
living object ,,ab1 ,fig4 #g1 is covered
 with black  cloth1 the head of a person
 or of an animal placed above ,a might  
be set  upon the shoulders of the figure
 ,,ab by the refraction of a prism4     

,illustration3 ,fig4 #h4    ,when the   
figure ab1 ,fig4 #h1 is of very small   
dimensions1 as in the  magic lantern1 a 
small prism of glass would answer the   
purpose required  of it2 but in public  
exhibitions1 where the image ab must be 
of a  considerable size1 if formed by a 
concave mirror1 a very large prism      
would be necessary4 ,this1 however1     
though impracticable with solid  glass1 
may be easily obtained by means of two  
large pieces of plate  glass made into a
 prismatic vessel and filled with water4
 ,two of the  glasses of a carriage     
window would make a prism capable of    
doubling  the whole of the bust of a    
living person placed as an object at    
,,ab1  ,fig4 #g1 so that two perfectly  
similar phantasms might be exhibited4   
,in  those cases where the images before
 the lens ,,ll are small1 they may  be  
doubled and even tripled by interposing 
a well-prepared plate of  calcareous    
spar1 that is1 crossed by a thin film4  
,these images would  possess the        

singular character of being oppositely  
coloured1 and of  changing their        
distances and their colours1 by slight  
variations in the  positions of the     
plate4#h     #h ,see ,edin4             
,encyclopdia1 ,art4 ,,optics1 ,vol4 xv41
 p4 #faa4    ,in order to render the    
images which are formed by the glass and
  water prisms as perfect as possible1  
it would be easy to make them           
achromatic1 and the figures might be    
multiplied to any extent by using       
several prisms1 having their refracting 
edges parallel1 for the purpose  of     
giving a similarity of position to all  
the images4    ,illustration3 ,fig4 #i4 
,among the instruments of natural magic 
which were in use at the revival  of    
science1 there was one invented by      
,kircher for exhibiting the  mysterious 
hand-writing on the wall of an          
apartment1 from which the  magician and 
his apparatus were excluded4 ,the       
annexed figure represents  this         
apparatus as given by ,schottus4 ,the   

apartment in which the  spectators are  
placed is between ,,ll and ,,gh1 and    
there is an open window  in the    side 
next ,,ll1 ,,gh being the inside of the 
wall opposite to the window4  ,upon the 
face of the plane speculum ,,ef are     
written the words to be  introduced1 and
 when a lens ,,ll is placed at such a   
distance from the  speculum1 and of such
 a focal length1 that the letters and   
the place  of their representation are  
in its conjugate foci1 a distinct image 
of the writing will be exhibited on the 
wall at ,,gh4 ,the letters on  the      
speculum are of course inverted1 as seen
 at ,,ef1 and when they are  illuminated
 by the sun's rays ,s1 as shown in the  
figure1 a distinct  image1 as ,schottus 
assures us1 may be formed at the        
distance of #ejj  feet4 ,in this        
experiment1 the speculum is by no means 
necessary4 ,if the  letters are cut out 
of an opaque card1 and illuminated by   
the light  of the sky in the day1 or by 
a lamp during night1 their delineation  

on the wall would be equally distinct4  
,in the daytime it would be  necessary  
to place the letters at one end of a    
tube or oblong box1 and  the lens at the
 other end4 ,as this deception is       
performed when the  spectators are      
unprepared for any such exhibition1 the 
warning written  in luminous letters on 
the wall1 or any word associated with   
the fate  of the individual observer1   
could not fail to produce a singular    
effect  upon his mind4 ,the words might 
be magnified1 diminished1 multiplied1   
coloured1 and obliterated1 in a cloud of
 light1 from which they might  again    
reappear by the methods already         
described1 as applicable to the  magic  
lantern4    ,the art of forming arial   
representations was a great desideratum 
among  the opticians of the #agth       
century4 ,vitellio and others had made  
many  unsuccessful attempts to produce  
such images1 and the speculations  of   
,lord ,bacon on the subject are too     
curious to be withheld from the  reader4

    8,it would be well bolted out10 says
 he1 8whether great refractions may  not
 be made upon reflexions1 as well as    
upon direct beams4 ,for example1  take  
an empty basin1 put an angel or what you
 will into it2 then go so  far from the 
basin till you cannot see the angel1    
because it is not in  a right line2 then
 fill the basin with water1 and you     
shall see it out  of its place1 because 
of the refraction4 ,to proceed1         
therefore1 put a  looking-glass into a  
basin of water4 ,i suppose you shall not
 see the  image in a right line or at   
equal angles1 but wide4 ,i know not     
whether  this experiment may not be     
extended1 so as you might see the image 
and  not the glass1 which1 for beauty   
and strangeness1 were a fine proof1  for
 then you should see the image like a   
spirit in the air4 ,as1 for  example1 if
 there be a cistern or pool of water1   
you shall place over  against it the    
picture of the devil1 or what you will1 
so as that you  do not see the water4   

,then put a looking-glass in the water2 
now if you  can see the devil's picture 
aside1 not seeing the water1 it would   
look  like the devil indeed4 ,they have 
an old tale in ,oxford1 that ,friar     
,bacon walked between two steeples1     
which was thought to be done by         
glasses1 when he walked upon the        
ground40    ,illustration3 ,fig4 #aj4   
,kircher also devoted himself to the    
production of such images1 and he  has  
given in the annexed figure his method  
of producing them4 ,at the  bottom of a 
polished cylindrical vessel ,,ab1 he    
placed a figure ,,cd1  which we presume 
must have been highly illuminated from  
below1 and  to the spectators who looked
 into the vessel in an oblique direction
  there was exhibited an image placed   
vertically in the air as if it  were    
ascending at the mouth of the vessel4   
,kircher assures us that he  once       
exhibited in this manner a              
representation of the ,ascension of our 
,saviour1 and that the images were so   

perfect that the spectators could  not  
be persuaded1 till they had attempted to
 handle them1 that they  were not real  
substances4 ,although ,kircher does not 
mention it1 yet  it is manifest that the
 original figure ,,ab must have been a  
deformed  or anamorphous drawing1 in    
order to give a reflected image of just 
proportions4 ,we doubt1 indeed1 if the  
representation or the figure was  ever  
exhibited4 ,it is entirely incompatible 
with the laws of reflexion4             
,illustration3 ,fig4 #aa4    ,among the 
ingenious and beautiful deceptions of   
the #agth century1  we must enumerate   
that of the re-formation of distorted   
pictures  by reflexion from cylindrical 
and conical mirrors4 ,in these          
representations1 the original image from
 which a perfect picture  is produced is
 often so completely distorted1 that the
 eye cannot  trace in it the resemblance
 to any regular figure1 and the greatest
  degree of wonder is of course excited1
 whether the original image is          

concealed or exposed to view4 ,these    
distorted pictures may be drawn  by     
strict geometrical rules2 but ,i have   
shown in ,fig4 #aa a simple and         
practical method of executing them4 ,let
 ,,mn be an accurate cylinder made  of  
tin-plate or of thick pasteboard4 ,out  
of the farther side of it  cut a small  
aperture abcd2 and out of the nearer    
side cut a larger  one ,,abcd1 the size 
of the picture to be distorted4 ,having 
perforated  the outline of the picture  
with small holes1 place it on the       
opening  ,,abcd1 so that its surface may
 be cylindrical4 ,let a candle or a     
bright  luminous object1 the smaller the
 better1 be placed at ,s1 as far behind 
the picture ,,abcd as the eye is        
afterwards to be placed before it1  and 
the light passing through the small     
holes will represent on a  horizontal   
plane a distorted image of the picture  
,a,b,c,d1 which1  when sketched in      
outline with a pencil1 and shaded or    
coloured1 will  be ready for use4 ,if we

 now substitute a polished cylindrical  
mirror  of the same size in place of    
,,mn1 then the distorted picture1 when  
laid horizontally at ,a,b,c,d1 will be  
restored to its original state  when    
seen by reflexion at ,,abcd in the      
polished mirror4 ,it would be  an       
improvement on this method to place at  
,,abcd a thin and flexible  plate of    
transparent mica1 having drawn upon it  
with a sharp point1  or painted upon it1
 the figure required4 ,the projected    
image of this  figure at ,a,b,c,d may   
then be accurately copied4    ,the      
effect of a cylindrical mirror is shown 
in ,fig4 #ab1 which is  copied from an  
old one which we have seen in use4      
,illustration3 ,fig4 #ab4    ,the method
 above described is equally applicable  
to concave cylindrical  mirrors1 and to 
those of a conical form2 and it may also
 be applied  to mirrors of variable     
curvature1 which produce different kinds
 of  distortions from different parts of
 their surfaces4    ,illustration3 ,fig4

 #ac4    ,by employing a mirror whose   
surface has a variable curvature like   
,,abc1  ,fig4 #ac1 we obtain an         
instrument for producing an endless     
variety of  caricatures1 all of which   
are characterised by their resemblance  
to  the original4 ,if a figure ,,mn is  
placed before such a mirror1 it will  of
 course appear distorted and            
caricatured2 but even if the figure     
takes different distances and positions1
 the variations which the  image        
undergoes are neither sufficiently      
numerous nor remarkable to  afford much 
amusement4 ,but if the figure ,,mn is   
very near the mirror1  so that new      
distortions are produced by the         
different distances of  its different   
parts from the mirror1 the most singular
 caricatures may  be exhibited4 ,if the 
figure1 for example1 bends forwards his 
head and  the upper part of his body1   
they will swell in size1 leaving his    
lower  extremities short and slender4   
,if it draws back the upper part of the 

body and advances the limbs1 the        
opposite effect will take place4 ,in    
like manner different sides of the head1
 the right or the left side of  it1 the 
brow or the chin1 may be swelled and    
contracted at pleasure4 ,by  stretching 
out the arms before the body they become
 like those of an  ourang-outang1 and by
 drawing them back they dwindle into    
half their  regular size4 ,all these    
effects1 which depend chiefly on the    
agility  and skill of the performer1 may
 be greatly increased by suitable       
distortions in his own features and     
figure4 ,the family likeness1 which  is 
of course never lost in all the variety 
of figures which are thus  produced1    
adds greatly to the interest of the     
exhibition2 and we have  seen           
individuals so annoyed at recognising   
their own likeness in the  hideous forms
 of humanity which were thus delineated1
 that they could  not be brought to     
contemplate them a second time4 ,if the 
figure is  inanimate1 like the small    

cast of a statue1 the effect is very    
curious1  as the swelling and           
contracting of the parts and the sudden 
change  of expression give a sort of    
appearance of vitality to the image4    
,the inflexibility of such a figure1    
however1 is unfavourable to its         
transformation into caricatures4        
,interesting as these metamorphoses are1
 they lose in the simplicity  of the    
experiment much of the wonder which they
 could not fail to  excite if exhibited 
on a great scale1 where the performer is
 invisible1  and where it is practicable
 to give an arial representation of the 
caricatured figures4 ,this may be done  
by means of the apparatus shown  in     
,fig4 #g1i where we may suppose ,,ab to 
be the reduced image seen in  the       
reflecting surface ,,abc1 ,fig4 #ac4aj  
,by bringing this image nearer  the     
mirror ,,mm1 ,fig4 #g1 a magnified and  
inverted image of it may be  formed at  
ab1 of such a magnitude as to give the  
last image in ,,pq the  same size as    

life4 ,owing to the loss of light by the
 two reflexions1 a  very powerful       
illumination would be requisite for the 
original figure4  ,if such an exhibition
 were well got up1 the effect of it     
would be very  striking4     #i ,page   
#hf4     #aj ,page #if4                 
,,letter ,v4     ,miscellaneous optical 
illusions--,conversion of cameos into   
intaglios1   or elevations into         
depressions1 and the                    
reverse--,explanation of   this class of
 deceptions--,singular effects of       
illumination with   light of one simple 
colour--,lamps for producing homogeneous
 yellow   light--,methods of increasing 
the effect of this exhibition--,method  
of reading the inscription of coins in  
the dark--,art of deciphering   the     
effaced inscription of                  
coins--,explanation of these singular   
effects--,apparent motion of the eyes in
 portraits--,remarkable examples   of   
this--,apparent motion of the features  
of a portrait1 when the   eyes are made 

to move--,remarkable experiment of      
breathing light and   darkness4      ,in
 the preceding letter ,i have given an  
account of the most important           
instruments of ,natural ,magic which    
depend on optical principles3 but  there
 still remain several miscellaneous     
phenomena on which the stamp  of the    
marvellous is deeply impressed1 and the 
study of which is  pregnant with        
instruction and amusement4    ,one of   
the most curious of these is that false 
perception in vision  by which we       
conceive depressions to be elevations1  
and elevations  depressions1 or by which
 intaglios are converted into cameos1   
and  cameos into intaglios4 ,this       
curious fact seems to have been first   
observed at one of the early meetings of
 the ,royal ,society of ,london1  when  
one of the members1 in looking at a     
guinea through a compound  microscope of
 new construction1 was surprised to see 
the head upon the  coin depressed1 while
 other members could only see it        

embossed as it  really was4    ,while   
using telescopes and compound           
microscopes1 ,dr4 ,gmelin of            
,wurtemburg observed the same fact4 ,the
 protuberant parts of objects  appeared 
to him depressed1 and the depressed     
parts protuberant3 but  what perplexed  
him extremely1 this illusion took place 
at some times  and not at others1 in    
some experiments and not in others1 and 
appeared  to some eyes and not to       
others4    ,after making a great number 
of experiments1 ,dr4 ,gmelin is said to 
have constantly observed the following  
effects3 ,whenever he viewed  any object
 rising upon a plane of any colour      
whatever1 provided it  was neither white
 nor shining1 and provided the eye and  
the optical  tube were directly opposite
 to it1 the elevated parts appeared     
depressed1 and the depressed parts      
elevated4 ,this happened when he  was   
viewing a seal1 and as often as he held 
the tube of the telescope               
perpendicularly1 and applied it in such 

a manner that its whole  surface almost 
covered the last glass of the tube4 ,the
 same effect was  produced when a       
compound microscope was used4 ,when the 
object hung  perpendicularly1 from a    
plane1 and the tube was supported       
horizontally  and directly opposite to  
it1 the illusion also took place1 and   
the  appearance was not altered when the
 object hung obliquely and even         
horizontally4 ,dr4 ,gmelin is said to   
have at last discovered a method  of    
preventing this illusion1 which was by  
looking1 not towards the  centre of the 
convexity1 but at first to the edges of 
it only1 and then  gradually taking in  
the whole4 8,but why these things should
 so happen1  he did not pretend to      
determine40    ,illustration3 ,fig4 #ad4
    ,the best method of observing this  
deception is to view the engraved  seal 
of a watch with the eyepiece of an      
achromatic telescope1 or with  a        
compound microscope1 or any combination 
of lenses which inverts the  objects    

that are viewed through it4#aa ,the     
depression in the seal  will immediately
 appear an elevation1 like the wax      
impression which  is taken from it2 and 
though we know it to be hollow1 and feel
 its  concavity with the point of our   
finger1 the illusion is so strong  that 
it continues to appear a protuberance4  
,the cause of this will be  understood  
from ,fig4 #ad1 where ,s is the window  
of the apartment1 or  the light which   
illuminates the hollow seal ,,lr1 whose 
shaded side  is of course on the same   
side ,l with the light4 ,if we now      
invert the  seal1 with one or more      
lenses1 so that it may look in the      
opposite  direction1 it will appear to  
the eye as in ,fig4 #ae1 with the shaded
  side ,l farthest from the window4 ,but
 as we know that the window is  still on
 our left hand1 and that the light falls
 in the direction ,,rl1  and as         
everybody with its shaded side farthest 
from the light must  necessarily be     
convex or protuberant1 we immediately   

believe that the  hollow seal is now a  
cameo or bas-relief4 ,the proof which   
the eye thus  receives of the seal being
 raised1 overcomes the evidence of its  
being  hollow1 derived from our actual  
knowledge1 and from the sense of touch4 
,in this experiment the deception takes 
place from our knowing the real         
direction of the light which falls upon 
the seal2 for if the place of  the      
window1 with respect to the seal1 had   
been inverted as well as the  seal      
itself1 the illusion could not have     
taken place4     #aa ,a single convex   
lens will answer the purpose1 provided  
we hold   the eye six or eight inches   
behind the image of the seal formed in  
its   conjugate focus4    ,illustration3
 ,fig4 #ae4    ,illustration3 ,fig4 #af4
    ,in order to explain this better1   
let us suppose the seal ,,lr1 ,fig4 #ad1
  to be illuminated with a candle ,s1   
the place of which we can change at     
pleasure4 ,if we invert ,,lr1 it will   
rise into a cameo1 as in ,fig4 #ae2  and

 if we then place another candle ,s on  
the other side of it1 as in  ,fig4 #af1 
the hollow seal will be equally         
illuminated on all sides1 and  it will  
sink down into a cavity or intaglio4 ,if
 the two candles do not  illuminate the 
seal equally1 or if any accidental      
circumstance produces  a belief that the
 light is wholly or principally on one  
side1 the mind  will entertain a        
corresponding opinion respecting the    
state of the  seal1 regarding it as a   
hollow if it believes the light to come 
wholly  or principally from the right   
hand1 and as a cameo if it believes the 
light to come from the left hand4    ,if
 we use a small telescope to invert the 
seal1 and if we cover up  all the candle
 but the flame1 and arrange the         
experiment so that the  candle may be   
inverted along with the image1 the seal 
will still retain  its concavity1       
because the shadow is still on the same 
side with the  illuminating body4    ,if
 we make the same experiments with the  

raised impression of the seal  taken    
upon wax1 we shall observe the very same
 phenomena1 the seal  being depressed   
when it alone is inverted1 and retaining
 its convexity  when the light is       
inverted along with it4    ,the         
illusion1 therefore1 under our          
consideration is the result of an       
operation of our own minds1 whereby we  
judge of the forms of bodies by  the    
knowledge we have acquired of light and 
shadow4 ,hence the illusion  depends on 
the accuracy and extent of our knowledge
 on this subject2  and while some       
persons are under its influence1 others 
are entirely  insensible to it4 ,when   
the seal or hollow cavity is not        
polished1 but  ground1 and the surface  
round it of uniform colour and          
smoothness1  almost every person1       
whether young or old1 learned or        
ignorant1 will be  subject to the       
illusion2 because the youngest and the  
most careless  observers cannot but know
 that the shadow of a hollow is always  

on  the side next the light1 and the    
shadow of a protuberance on the side    
opposite to the light2 but if the object
 is the raised impression of a  seal    
upon wax1 ,i have found that1 when      
inverted1 it still seemed raised  to the
 three youngest of six persons1 while   
the three eldest were  subject to the   
deception4    ,illustration3 ,fig4 #ag4 
,this illusion may be dissipated by a   
process of reasoning arising from  the  
introduction of a new circumstance in   
the experiment4 ,thus1 let ,,rl1  ,fig4 
#ag1 be the inverted seal1 which        
consequently appears raised1 and  let an
 opaque and unpolished pin1 ,a1 be      
placed on one side of the seal4  ,its   
shadow will be of course opposite the   
candle as at ,b4 ,in this case  the     
seal1 which had become a cameo by its   
inversion1 will now sink down  into a   
cavity by the introduction of the pin   
and its shadow2 for as the  pin and its 
shadow are inverted1 as shown in ,fig4  
#ah1 while the candle  retains its      

place1 the shadow of the pin falling in 
the direction ,,ab  is a stronger proof 
to the eye that the light is coming from
 the right  hand1 than the actual       
knowledge of the candle being on the    
left hand1  and therefore the cameo     
necessarily sinks into a cavity1 or the 
shadow  is now on the same side as the  
light4 ,this experiment will explain to 
us why on some occasions an acute       
observer will elude the deception1      
while every other person is subject to  
it4 ,let us suppose that a  particle of 
dust1 or a little bit of wax1 capable of
 giving a shadow1  is adhering to the   
surface of the seal1 an ordinary        
observer will  take no notice of this1  
or if he does1 he will probably not make
 it a  subject of consideration1 and    
will therefore see the head on the seal 
raised into a cameo2 but the attentive  
observer1 noticing the little           
protuberance1 and observing that its    
shadow lies to the left of it1  will    
instantly infer that the light comes in 

that direction1 and will  still see the 
seal hollow4    ,illustration3 ,fig4    
#ah4    ,i have already mentioned that  
in some cases even the sense of touch   
does not correct the erroneous          
perception4 ,we of course feel that the 
part of the hollow on which the finger  
is placed is actually hollow2  but if we
 look at the other part of the hollow it
 will still appear  raised4    ,by using
 two candles yielding different degrees 
of light1 and thus  giving an           
uncertainty to the direction of the     
light1 we may weaken the  illusion in   
any degree we choose1 so as to overpower
 it by touch1 or by  a process of       
reasoning4    ,i have had occasion to   
observe a series of analogous phenomena 
arising  from the same cause1 but       
produced without any instrument for     
inverting  the object4 ,if ,,ab1 for    
example1 is a plate of mother-of-pearl1 
and ,,lr  a circular or any other cavity
 7,fig4 #ai7 ground or turned in it1    
then  if this cavity is illuminated by a

 candle or a window at ,s1 in place of  
there being a shadow of the margin ,l of
 the hollow next the light1 as  there   
would have been had the body been       
opaque1 a quantity of bright  refracted 
light will appear where there would have
 been a shadow1 and  the rest of the    
cavity will be comparatively obscure1 as
 if it were  in shade4 ,the necessary   
consequence of this is1 that the cavity 
will  appear as an elevation when seen  
only by the naked eye1 as it is only  an
 elevated surface that could have its   
most luminous side at ,l4               
,illustration3 ,fig4 #ai4    ,similar   
illusions take place in certain pieces  
of polished wood1  chalcedony1 and      
mother-of-pearl1 where the surface is   
perfectly  smooth4 ,this arises from    
there being at that place a knot or     
growth1  or nodule1 of different        
transparency from the surrounding mass1 
and  the cause of it will be understood 
from ,fig4 #bj4 ,let m o be the  surface
 of a mahogany table1 m ,a o ,b a       

section of the table1 and  m n o a      
section of a knot more transparent than 
the rest of the  mass4 ,owing to the    
transparency of the thin edge at o1     
opposite to  the candle ,s1 the side o  
is illuminated1 while the rest of the   
knot  is comparatively dark1 so that1 on
 the principles already explained1  the 
spot m n o appears to be a hollow in the
 table4 ,from this cause  arises the    
appearance of dimples in certain plates 
of chalcedony1  called hammered         
chalcedony1 owing to its having the look
 of being  dimpled with a hammer4 ,the  
surface on which these cavities are seen
 is  a section of small spherical       
aggregations of siliceous matter1 which 
exhibit the same phenomena as the       
cavities in wood4 ,mother-of-pearl      
presents the very same phenomena1 and it
 is indeed so common in this  substance1
 that it is nearly impossible to find a 
mother-of-pearl  button or counter which
 seems to have its surface flat1        
although they  are perfectly so when    

examined by the touch4 ,owing to the    
different  refraction of the incident   
light by the different growths of the   
shell  cut in different directions by   
the artificial surface1 like the annual 
growth of wood in a dressed plank1 the  
surface has necessarily an  unequal and 
undulating appearance4    ,illustration3
 ,fig4 #bj4    ,among the wonders of    
science there are perhaps none more     
surprising  than the effects produced   
upon coloured objects by illuminating   
them with homogeneous light1 or light of
 one colour4 ,the light which  emanates 
from the sun1 and by which all the      
objects of the material  world are      
exhibited to us1 is composed of three   
different colours1  red1 yellow1 and    
blue1 by the mixture of which in        
different  proportions all the various  
hues of nature may be produced4 ,these  
three  colours1 when mixed in the       
proportion in which they occur in the   
sun's  rays1 compose a purely white     
light2 but if any body on which this    

white  light falls shall absorb1 or     
stop1 or detain within its substance any
  part of any one or more of these      
simple colours1 it will appear to the   
eye of that colour which arises from the
 mixture of all the rays which  it does 
not absorb1 or of that colour which     
white light would have if  deprived of  
the colours which are absorbed4 ,scarlet
 cloth1 for example1  absorbs most of   
the blue rays and many of the yellow1   
and hence appears  red4 ,yellow cloth   
absorbs most of the blue and many of the
 red rays1  and therefore appears       
yellow2 and blue cloth absorbs most of  
the yellow  and red rays4 ,if we were to
 illuminate the scarlet cloth with pure 
and unmixed yellow light1 it would      
appear yellow1 because the  scarlet     
cloth does not absorb all the yellow    
rays1 but reflects some  of them2 and if
 we illuminate blue cloth with yellow   
light1 it will  appear nearly black1    
because it absorbs all the yellow light1
 and  reflects almost none of it4 ,but  

whatever be the nature and colour of    
the bodies on which the yellow light    
falls1 the light which it reflects  must
 be yellow1 for no other light falls    
upon them1 and those which are  not     
capable of reflecting yellow light must 
appear absolutely black1  however       
brilliant be their colour in the light  
of day4    ,illustration3 ,fig4 #ba4    
,as the methods now discovered of       
producing yellow light in abundance     
were not known to the ancient conjurors1
 nor even to those of later  times1 they
 have never availed themselves of this  
valuable resource4 ,it  has been long   
known that salt thrown into the wick of 
a flame produces  yellow light1 but this
 light is mixed with blue and green     
rays1 and is1  besides1 so small in     
quantity1 that it illuminates objects   
only that  are in the immediate vicinity
 of the flame4 ,a method which ,i have  
found  capable of producing it in       
abundance is shown in ,fig4 #ba1 where  
,,ab is a  lamp1 containing at ,a a     

large quantity of alcohol and water1 or 
ardent  spirits1 which gradually        
descends into a platina or metallic cup 
,d4  ,this cup is strongly heated by a  
spirit-lamp ,l1 inclosed in a dark      
lantern1 and when the diluted alcohol in
 ,d is inflamed1 it will burn  with a   
fierce and powerful yellow flame4 ,if   
the flame should not be  perfectly      
yellow1 owing to an excess of alcohol1 a
 proportion of salt  thrown into the cup
 will answer the same purpose as a      
further dilution  of the alcohol4#ab    
#ab ,see ,edinburgh ,transactions1 vol4 
ix41 p4 #dce4    ,a monochromatic lamp  
for producing yellow light may be       
constructed most  effectually1 by       
employing a portable gas lamp1          
containing compressed  oil gas4 ,if we  
allow the gas to escape in a copious    
stream1 and set it  on fire1 it will    
form an explosive mixture with the      
atmospheric air1  and will no longer    
burn with a white flame1 but will emit a
 bluish  and reddish light4 ,the force  

of the issuing gas1 or any accidental   
current of air1 is capable of blowing   
out this flame1 so that it is  necessary
 to have a contrivance for sustaining   
it4 ,the method which ,i  used for this 
purpose is shown in ,fig4 #bb4 ,a small 
gas tube a b c1  arising from the main  
burner ,,mn of the gas lamp ,,pq1       
terminates above  the burner1 and has a 
short tube d e1 moveable up and down    
within it1  so as to be gas-tight4 ,this
 tube d e1 closed at e1 communicates    
with the hollow ring f g1 in the inside 
of which four apertures are  perforated 
in such a manner as to throw their jets 
of gas to the apex  of a cone1 of which 
f g is the base4 ,when we cause the gas 
to flow  from the burner ,m1 by opening 
the main cock ,a1 it will rush into the 
tube a b c d1 and issue in small flames 
at the four holes in the  ring f g4 ,the
 size of these flames is regulated by   
the cock b4  ,the inflammation1         
therefore1 of the ignited gas will be   
sustained by  these four subsidiary     

flames through which it passes1         
independent of  any agitation of the    
air1 or of the force with which it      
issues from  the burner4 ,on a          
projecting arm e h1 carrying a ring h1  
,i fixed a  broad collar1 made of coarse
 cotton wick1 which had been previously 
soaked in a saturated solution of common
 salt4 ,when the gas was allowed  to    
escape at ,m1 with such force as to     
produce a long and broad column  of an  
explosive mixture of gas and atmospheric
 air1 the bluish flame  occasioned by   
the explosion passes through the salted 
collar1 and is  converted by it into a  
mass of homogeneous yellow light4 ,this 
collar  will last a long time without   
any fresh supply of salt1 so that the   
gas  lamp will yield a permanent        
monochromatic yellow flame1 which will  
last as long as there is gas in the     
reservoir4 ,in place of a collar  of    
cotton wick1 a hollow cylinder of       
sponge1 with numerous projecting  tufts1
 may be used1 or a collar may be        

similarly constructed with  asbestos    
cloth1 and1 if thought necessary1 it    
might be supplied with a  saline        
solution from a capillary fountain4     
,illustration3 ,fig4 #bb4    ,having    
thus obtained the means of illuminating 
any apartment with  yellow light1 let   
the exhibition be made in a room with   
furniture of  various bright colours1   
with oil or water-coloured paintings on 
the  wall4 ,the party which is to       
witness the experiment should be dressed
  in a diversity of the gayest colours2 
and the brightest-coloured  flowers and 
highly-coloured drawings should be      
placed on the tables4  ,the room being  
at first lighted with ordinary lights1  
the bright and  gay colours of          
everything that it contains will be     
finely displayed4  ,if the white lights 
are now suddenly extinguished1 and the  
yellow  lamps lighted1 the most         
appalling metamorphosis will be         
exhibited4 ,the  astonished individuals 
will no longer be able to recognize each

 other4  ,all the furniture in the room1
 and all the objects which it contains1 
will exhibit only one colour4 ,the      
flowers will lose their hues4 ,the      
paintings and drawings will appear as if
 they were executed in ,china  ink2 and 
the gayest dresses1 the brightest       
scarlets1 the purest lilacs1  the       
richest blues1 and the most vivid       
greens1 will all be converted  into one 
monotonous yellow4 ,the complexions of  
the parties1 too1 will  suffer a        
corresponding change4 ,one pallid1      
death-like yellow1        ---- like the 
unnatural hue      ,which autumn paints 
upon the perished leaf1    will envelope
 the young and the old1 and the sallow  
faces will alone  escape from the       
metamorphosis4 ,each individual derives 
merriment from  the cadaverous          
appearance of his neighbour1 without    
being sensible that  he is himself one  
of the ghostly assemblage4    ,if1 in   
the midst of the astonishment which is  
thus created1 the white  lights are     

restored at one end of the room1 while  
the yellow lights are  taken to the     
other end1 one side of the dress of     
every person1 namely1  that next the    
white light1 will be restored to its    
original colours1  while the other side 
will retain its yellow hue4 ,one cheek  
will appear  in a state of health and   
colour1 while the other retains the     
paleness  of death2 and1 as the         
individuals change their position1 they 
will  exhibit the most extraordinary    
transformations of colour4    ,if1 when 
all the lights are yellow1 beams of     
white light are  transmitted through a  
number of holes1 like those in a sieve1 
each  luminous spot will restore the    
colour of the dress or furniture upon   
which it falls1 and the nankeen family  
will appear all mottled over  with every
 variety of tint4 ,if a magic lantern is
 employed to throw  upon the walls or   
upon the dresses of the company luminous
 figures of  flowers or animals1 the    
dresses will be painted with these      

figures  in the real colour of the dress
 itself4 ,those alone who appeared in   
yellow1 and with yellow complexions1    
will1 to a great degree1 escape  all    
these singular changes4    ,if red and  
blue light could be produced with the   
same facility and in  the same abundance
 as yellow light1 the illumination of   
the apartment  with these lights in     
succession would add to the variety and 
wonder of  the exhibition4 ,the red     
light might perhaps be procured in      
sufficient  quantity from the nitrate   
and other salts of strontian2 but it    
would  be difficult to obtain a blue    
flame of sufficient intensity for the   
suitable illumination of a large room4  
,brilliant white lights1 however1  might
 be used1 having for screens glass      
troughs containing a mass  one or two   
inches thick of a solution of the       
ammoniacal carbonate of  copper4 ,this  
solution absorbs all the rays of the    
spectrum but the  blue1 and the         
intensity of the blue light thus        

produced would increase  in the same    
proportion as the white light employed4 
,amongst the numerous experiments with  
which science astonishes and  sometimes 
even strikes terror into the ignorant1  
there is none more  calculated to       
produce this effect than that of        
displaying to the eye in  absolute      
darkness the legend or inscription upon 
a coin4 ,to do this1  take a silver coin
 7,i have always used an old one71 and  
after polishing  the surface as much as 
possible1 make the parts of it which are
 raised  rough by the action of an acid1
 the parts not raised1 or those which   
are to be rendered darkest1 retaining   
their polish4 ,if the coin thus         
prepared is placed upon a mass of       
red-hot iron1 and removed into a dark   
room1 the inscription upon it will      
become less luminous than the rest1  so 
that it may be distinctly read by the   
spectator4 ,the mass of red-hot  iron   
should be concealed from the observer's 
eye1 both for the purpose  of rendering 

the eye fitter for observing the effect1
 and of removing  all doubt that the    
inscription is really read in the dark1 
that is1  without receiving any light1  
direct or reflected1 from any other     
body4  ,if1 in place of polishing the   
depressed parts and roughening its      
raised  parts1 we make the raised parts 
polished and roughen the depressed      
parts1 the inscription will now be less 
luminous than the depressed  parts1 and 
we shall still be able to read it1 from 
its being as it were  written in black  
letters on a white ground4 ,the first   
time ,i made this  experiment1 without  
being aware of what would be the result1
 ,i used  a ,french shilling of ,louis  
,,xv41 and ,i was not a little surprised
 to  observe upon its surface1 in black 
letters1 the inscription ,,benedictum   
,,sit ,,nomen ,,dei4    ,the most       
surprising form of this experiment is   
when we use a coin  from which the      
inscription has been either wholly      
obliterated1 or  obliterated in such a  

degree as to be illegible4 ,when such a 
coin is  laid upon the red-hot iron1 the
 letters and figures become oxidated1   
and the film of oxide radiating more    
powerfully than the rest of the  coin1  
the illegible inscription may be now    
distinctly read1 to the  great surprise 
of the observer1 who had examined the   
blank surface of  the coin previous to  
its being placed upon the hot iron4 ,the
 different  appearances of the same     
coin1 according as the raised parts are 
polished or roughened1 are shown in     
,fig4 #bc and #bd4    ,in order to      
explain the cause of these remarkable   
effects1 we must  notice a method which 
has been long known1 though never       
explained1 of  deciphering the          
inscriptions on worn-out coins4 ,this is
 done by merely  placing the coin upon a
 hot iron2 an oxidation takes place over
 the  whole surface of the coin1 the    
film of oxide changing its tint with the
  intensity or continuance of the heat4 
,the parts1 however1 where the  letters 

of the inscription had existed1 oxidate 
at a different rate  from the           
surrounding parts1 so that these letters
 exhibit their shape1  and become       
legible in consequence of the film of   
oxide which covers  them having a       
different thickness1 and therefore      
reflecting a different  tint from that  
of the adjacent parts4 ,the tints thus  
developed  sometimes pass through many  
orders of brilliant colours1            
particularly  pink and green1 and settle
 in a bronze1 and sometimes a black     
tint1  resting upon the inscription     
alone4 ,in some cases the tint left on  
the  trace of the letters is so very    
faint that it can just be seen1 and may 
be entirely removed by a slight rub of  
the finger4    ,illustration3 ,fig4 #bc4
    ,illustration3 ,fig4 #bd4    ,when  
the experiment is often repeated with   
the same coin1 and the  oxidations      
successively removed after each         
experiment1 the film of  oxide continues
 to diminish1 and at last ceases to make

 its appearance4  ,it recovers the      
property1 however1 in the course of     
time4 ,when the  coin is put upon the   
hot iron1 and consequently when the     
oxidation  is the greatest1 a           
considerable smoke arises from the coin1
 and this  diminishes like the film of  
oxide by frequent repetition4 ,a coin   
which had ceased to emit this smoke1    
smoked slightly after having been       
exposed twelve hours to the air4 ,i have
 found1 from numerous trials1  that it  
is always the raised parts of the coin1 
and in modern coins the  elevated ledge 
round the inscription1 that become first
 oxidated4 ,in an  ,english shilling of 
#ahaf1 this ledge exhibited a brilliant 
yellow tint  before it appeared on any  
other part of the coin4    ,if we use a 
uniform and homogeneous disc of silver  
that has never been  hammered or        
compressed1 its surface will oxidate    
equally1 provided all  its parts are    
equally heated4 ,in the process of      
converting this disc  into a coin1 the  

sunk parts have obviously been most     
compressed  by the prominent parts of   
the die1 and the elevated parts least   
compressed1 the metal being in the      
latter left as it were in its  natural  
state4 ,the raised letters and figures  
on a coin have therefore  less density  
than the other parts1 and these parts   
oxidate sooner or  at a lower           
temperature4 ,when the letters of the   
legend are worn off by  friction1 the   
parts immediately below them have also  
less density than  the surrounding      
metal1 and the site as it were of the   
letters therefore  receives from heat a 
degree of oxidation1 and a colour       
different from  that of the surrounding 
surface4 ,hence we obtain an explanation
 of the  revival of the invisible       
letters by oxidation4    ,the same      
influence of difference of density may  
be observed in  the beautiful oxidations
 which are produced on the surface of   
highly-polished steel1 heated in contact
 with air1 at temperatures  between #dcj

 and #fcj of ,fahrenheit4#ac ,when the  
steel has hard  portions called pins by 
the workmen1 the uniform tint of the    
film of  oxide stops near these hard    
portions1 which always exhibit colours  
different from those of the rest of the 
mass4 ,these parts1 on account  of their
 increased density1 absorb the oxygen of
 atmospheric air less  copiously than   
the surrounding portions4 ,hence we see 
the cause why  steel expanded by heat   
absorbs oxygen1 which when united with  
the  metal1 forms the coloured          
superficial film4 ,as the heat          
increases1  a greater quantity of oxygen
 is absorbed1 and the film increases in 
thickness4     #ac ,see ,edinburgh      
,encyclopdia1 ,art4 ,,steel1 vol4       
xviii41 p4 #chg4    ,these observations 
enable us to explain the legibility of  
inscriptions  in the dark1 whether the  
coin is in a perfect state1 or the      
letters  of it worn off4 ,all black or  
rough surfaces radiate light more       
copiously than polished or smooth       

surfaces1 and hence the  inscription is 
luminous when it is rough1 and obscure  
when it is  polished1 and the letters   
covered with black oxide are more       
luminous  than the adjacent parts1 on   
account of the superior radiation of    
light  by the black oxide which covers  
them4    ,by the means now described1   
invisible writing might be conveyed by  
impressing it upon a metallic surface1  
and afterwards erasing it by  grinding  
and polishing that surface perfectly    
smooth4 ,when exposed to  a proper      
degree of heat1 the secret would display
 itself written in  oxidated letters4   
,many amusing experiments might be made 
upon the same  principle4    ,a series  
of curious and sometimes alarming       
deceptions1 arises from the             
representation of objects in perspective
 upon a plane surface4 ,one of  the most
 interesting of these depends on the    
principles which regulate  the apparent 
direction of the eyes in a portrait4    
,dr4 ,wollaston has  thought this       

subject of sufficient importance to be  
treated at some  length in the          
,philosophical ,transactions4 ,when we  
look at any person  we direct to them   
both our face and our eyes1 and in this 
position  the circular iris will be in  
the middle of the white of the eye ball1
  or1 what is the same thing1 there will
 be the same quantity of white  on each 
side of the iris4 ,if the eyes are now  
moved to either side1  while the head   
remains fixed1 we shall readily judge of
 the change of  their direction by the  
greater or less quantity of white on    
each side  of the iris4 ,this test1     
however1 accurate as it is1 enables us  
only to  estimate the extent to which   
the eyes deviate in direction from the  
direction of the face to which they     
belong4 ,but their direction in         
reference to the person who views them  
is entirely a different matter2  and    
,dr4 ,wollaston is of opinion1 that we  
are not guided by the eyes  alone1 but  
are unconsciously aided by the          

concurrent position of the  entire face4
    ,illustration3 ,fig4 #bf4    ,if a  
skilful painter draws a pair of eyes    
with great correctness  directed to the 
spectator1 and deviating from the       
general position of  the face as much as
 is usual in good portraits1 it is very 
difficult  to determine their direction1
 and they will appear to have different 
directions to different persons4 ,but   
what is very curious1 ,dr4  ,wollaston  
has shown that the same pair of eyes may
 be made to direct  themselves either to
 or from the spectator by the addition  
of other  features in which the position
 of the face is changed4 ,thus1 in ,fig4
  #be1 the pair of eyes are looking     
intently at the spectator1 and the  face
 has a corresponding direction2 but when
 we cover up the face in  ,fig4 #be with
 the face in ,fig4 #bf1 which looks to  
the right1 the eyes  change their       
direction1 and look to the right also4  
,in like manner1  eyes drawn originally 
to look a little to the right or the    

left of  the spectator1 may be made to  
look directly at him by adding suitable 
features4    ,illustration3 ,fig4 #be4  
,the nose is obviously the principal    
feature which produces this  change of  
direction1 as it is more subject to     
change of perspective  than any of the  
other features2 but ,dr4 ,wollaston has 
shown by a very  accurate experiment1   
that even a small portion of the nose   
introduced  with the features will carry
 the eyes along with it4 ,he obtained   
four  exact copies of the same pair of  
eyes looking at the spectator1 by       
transferring them upon copper from a    
steel plate1 and having added to  each  
of two pair of them a nose1 in one case 
directed to the right1  and in the other
 to the left1 and to each of the other  
two pair a very  small portion of the   
upper part of the nose1 all the four    
pair of eyes  lost their front          
direction1 and looked to the right or to
 the left1  according to the direction  
of the nose1 or of the portion of it    

which  was added4    ,but the effect    
thus produced is not limited1 as ,dr4   
,wollaston  remarks1 to the mere change 
in the direction of the eyes1 8for a    
total difference of character may be    
given to the same eyes by a due         
representation of the other features4 ,a
 lost look of devout abstraction  in an 
uplifted countenance1 may be exchanged  
for an appearance of  inquisitive       
archness in the leer of a younger face  
turned downwards and  obliquely towards 
the opposite side10 as in ,fig4 #bg1    
#bh4 ,this1 however1  is perhaps not an 
exact expression of the fact4 ,the new  
character  which is said to be given to 
the eyes is given only to the eyes in   
combination with the new features1 or1  
what is probably more correct1  the     
inquisitive archness is in the other    
features1 and the eye does not  belie   
it4    ,dr4 ,wollaston has not noticed  
the converse of these illusions1 in     
which  a change of direction is given to
 fixed features by a change in the      

direction of the eyes4 ,this effect is  
finely seen in some magic lantern       
sliders1 where a pair of eyes is made to
 move in the head of a figure1  which   
invariably follows the motion of the    
eyeballs4    ,illustration3 ,fig4 #bh4  
,illustration3 ,fig4 #bg4    ,having    
thus determined the influence which the 
general perspective of  the face has    
upon the apparent direction of the eyes 
in a portrait1 ,dr4  ,wollaston applies 
it to the explanation of the well-known 
fact1 that  when the eyes of a portrait 
look at a spectator in front of it they 
will follow him1 and appear to look at  
him in every other direction4  ,this    
curious fact1 which has received less   
consideration than it  merits1 has been 
often skilfully employed by the         
novelist1 in alarming  the fears or     
exciting the courage of his hero4 ,on   
returning to the  hall of his ancestors1
 his attention is powerfully fixed on   
the grim  portraits which surround him4 
,the parts which they have respectively 

performed in the family history rise to 
his mind3 his own actions1  whether good
 or evil1 are called up in contrast1 and
 as the preserver  or the destroyer of  
his line1 he stands1 as it were1 in     
judgment before  them4 ,his imagination1
 thus excited by conflicting feelings1  
transfers  a sort of vitality to the    
canvas1 and if the personages do not    
8start  from their frames10 they will at
 least bend upon him their frowns or    
their approbation4 ,it is in vain that  
he tries to evade their scrutiny4       
,wherever he goes their eyes eagerly    
pursue him2 they will seem even to  look
 at him over their shoulders1 and he    
will find it impossible to  shun their  
gaze but by quitting the apartment4     
,as the spectator in this case changes  
his position in a horizontal  plane1 the
 effect which we have described is      
accompanied by an apparent  diminution  
in the breadth of the human face1 from  
only seven or eight  inches till it     
disappears at a great obliquity4 ,in    

moving1 therefore1  from a front view to
 the most oblique view of the face1 the 
change in  its apparent breadth is so   
slow that the apparent motion of the    
head of  the figure is scarcely         
recognized as it follows the spectator4 
,but if  the perspective figure has a   
great breadth in a horizontal plane1    
such  as a soldier firing his musket1 an
 artilleryman his piece of ordnance1  a 
bowman drawing his bow1 or a lancer     
pushing his spear1 the apparent  breadth
 of the figure will vary from five to   
six feet or upwards till  it disappears1
 and therefore the change of apparent   
magnitude is  sufficiently rapid to give
 the figure the dreaded appearance of   
turning  round1 and following the       
spectator4 ,one of the best examples of 
this  must have been often observed in  
the foreshortened figure of a dead  body
 lying horizontally1 which has the      
appearance of following the  observer   
with great rapidity1 and turning round  
upon the head as the  centre of motion4 

,the cause of this phenomenon is easily 
explained4 ,let us suppose a  portrait  
with its face and its eyes directed     
straight in front1 so as  to look at the
 spectator4 ,let a straight line be     
drawn through the  tip of the nose and  
half way between the eyes1 which we     
shall call the  middle line4 ,on each   
side of this middle line there will be  
the same  breadth of head1 of cheek1 of 
chin1 and of neck1 and each iris will be
  in the middle of the white of the eye4
 ,if we now go to one side1 the         
apparent horizontal breadth of every    
part of the head and face will  be      
diminished1 but the parts on each side  
of the middle line will be  diminished  
equally1 and at any position1 however   
oblique1 there will be  the same breadth
 of face on each side of the middle     
line1 and the iris  will be in the      
centre of the white of the eyeball1 so  
that the portrait  preserves all the    
characters of a figure looking at the   
spectator1 and  must necessarily do so  

wherever he stands4    ,this explanation
 might be illustrated by a picture which
 represents  three artillerymen1 each   
firing a piece of ordnance in parallel  
directions4 ,let the gun of the middle  
one be pointed accurately to the  eye of
 the spectator1 so that he sees neither 
its right side nor its  left1 nor its   
upper nor its under side1 but directly  
down its muzzle1  so that if there was  
an opening in the breech he would see   
through  it4 ,in like manner the        
spectator will see the left side of the 
gun on  his left hand1 and the right    
side of the gun on his right hand4 ,if  
the spectator now changes his place1 and
 takes ever such an oblique  position1  
either laterally or vertically1 he must 
still see the same  thing2 because      
nothing else is presented to his view4  
,the gun of the  middle soldier must    
always point to his eye1 and the other  
guns to the  right and left of him4     
,they must therefore all three seem to  
move as  he moves1 and follow his eye in

 all its changes of place4 ,the same    
observations are of course applicable to
 buildings and streets seen in          
perspective4    ,in common portraits the
 apparent motion of the head is         
generally  rendered indistinct by the   
canvas being imperfectly stretched1 as  
the slightest concavity or convexity    
entirely deforms the face when  the     
obliquity is considerable4 ,the         
deception is therefore best seen  when  
the painting is executed on a very flat 
board1 and in colours  sufficiently     
vivid to represent every line in the    
face with tolerable  distinctness at    
great obliquities4 ,this distinctness of
 outline is  indeed necessary to a      
satisfactory exhibition of this optical 
illusion4  ,the most perfect exhibition1
 indeed1 that ,i ever saw of it was in  
the  case of a painting of a ship upon a
 sign-board executed in strongly  gilt  
lines4 ,it contained a view of the stern
 and side of a ship in the  stocks1 and1
 owing to the flatness of the board and 

the brightness of  the lines1 the       
gradual development of the figure1 from 
the most violent  foreshortening at     
great obliquities till it attained its  
perfect form1  was an effect which      
surprised every person that saw it4     
,illustration3 ,fig4 #bi4    ,the only  
other optical illusion which our limits 
will permit us to  explain1 is the very 
remarkable experiment of what may be    
truly called  breathing light or        
darkness4 ,let ,s be a candle whose     
light falls at  an angle of #ef #de upon
 two glass plates ,a1 ,b1 placed close  
to each  other1 and let the reflected   
rays ,,ac1 ,,bd1 fall at the same angle 
upon  two similar plates1 ,c1 ,d1 but so
 placed that the plane of reflexion     
from the latter is at right angles to   
the plane of reflexion from the  former4
 ,an eye placed at ,e1 and looking at   
the same time into the two  plates ,c   
and ,d1 will see very faint images of   
the candle ,s1 which by a  slight       
adjustment of the plates1 may be made to

 disappear almost wholly  allowing the  
plate ,c to remain as it is1 change the 
position of ,d1 till  its inclination to
 the ray ,,bd is diminished about #c1 or
 made nearly  #ec #aa4 ,when this is    
done1 the image that had disappeared on 
looking  into ,d will be restored1 so   
that the spectator at ,e1 upon looking  
into  the two mirrors ,c1 ,d1 will see  
no light in ,c1 because the candle has  
nearly disappeared1 while the candle is 
distinctly seen in ,d4 ,if1 while  the  
spectator is looking into these two     
mirrors1 either he or another  person   
breathes upon them gently and quickly1  
the breath will revive  the extinguished
 image in ,c1 and will extinguish the   
visible image  in ,d4 ,the following is 
the cause of this singular result4 ,the 
light  ,,ac1 ,,bd1 is polarized by      
reflexion from the plates ,a1 ,b1       
because it is  incident at the          
polarizing angle of #ef #de for glass4  
,when we breathe  upon the plates ,c1   
,d1 we form upon their surface a thin   

film of water1  whose polarizing angle  
is #ec #aa1 so that if the polarized    
rays ,,ac1  ,,bd1 fell upon the plates  
,c1 ,d1 at an angle of #ec #aa1 the     
candle from  which they proceeded would 
not be visible1 or they would not suffer
  reflexion from the plates ,c1 ,d4 ,at 
all other angles the light would  be    
reflected and the candles visible4 ,now 
the plate ,d is placed at an  angle of  
#ec #aa and ,c at an angle of #ef #de1  
so that when a film  of water is        
breathed upon them the light will be    
reflected from the  latter1 and none    
from the former2 that is1 the act of    
breathing upon  the plates will restore 
the invisible and extinguish the visible
 image4          ,,letter ,,vi4         
,natural phenomena marked with the      
marvellous--,spectre of the   ,brocken  
described--,analogous phenomena--,arial 
spectres seen in   ,cumberland--,fata   
,morgana in the ,straits of             
,messina--,objects below the   horizon  
raised and magnified by                 

refraction--,singular example seen at   
,hastings--,dover ,castle seen through  
the hill on which it stands--,erect     
and inverted images of distant ships    
seen in the air--,similar   phenomena   
seen in the ,arctic regions--,enchanted 
coast--,mr4   ,scoresby recognizes his  
father's ship by its arial              
image--,images   of cows seen in the    
air--,inverted image of horses seen in  
,south   ,america--,lateral images      
produced by refraction--,arial spectres 
by   reflexion--,explanation of the     
preceding phenomena4      ,among the    
wonders of the natural world which are  
every day presented  to us1 without     
either exciting our surprise or         
attracting our notice1  some are        
occasionally displayed which possess all
 the characters of  supernatural        
phenomena4 ,in the names by which they  
are familiarly  known1 we recognize the 
terror which they inspired1 and even    
now1  when science has reduced them to  
the level of natural phenomena1 and     

developed the causes from which they    
arise1 they still retain their          
primitive importance1 and are watched by
 the philosopher with as  intense an    
interest as when they were deemed the   
immediate effects  of ,divine power4    
,among these phenomena we may enumerate 
the ,spectre  of the ,brocken1 the ,fata
 ,morgana of the ,straits of ,messina1  
the  ,spectre ,ships which appear in the
 air1 and the other extraordinary       
effects of the ,mirage4#ad     #ad ,in  
the ,sanscrit1 says ,baron ,humboldt1   
the phenomenon of the   ,mirage is      
called ,mriga ,trichna1 8thirst or      
desire of the antelope10   no doubt     
because this animal ,mriga1 compelled by
 thirst1 ,trichna1   approaches those   
barren plains where1 from the effect of 
unequal   refraction1 he thinks he      
perceives the undulating surface of the 
waters4--,personal ,narrative1 vol4     
iii41 p4 #eed4    ,the ,brocken is the  
name of the loftiest of the ,hartz      
mountains1 a  picturesque range which   

lies in the kingdom of ,hanover4 ,it is 
elevated  #c1cjj feet above the sea1 and
 commands the view of a plain seventy   
leagues in extent1 occupying nearly the 
two-hundredth part of the  whole of     
,europe1 and animated with a population 
of above five millions  of inhabitants4 
,from the earliest periods of authentic 
history1 the  ,brocken has been the seat
 of the marvellous4 ,on its summits are 
still  seen huge blocks of granite      
called the ,sorcerer's ,chair and the   
,altar4  ,a spring of pure water is     
known by the name of the ,magic         
,fountain1  and the ,anemone of the     
,brocken is distinguished by the title  
of the  ,sorcerer's ,flower4 ,these     
names are supposed to have originated in
 the  rites of the great idol ,cortho1  
whom the ,saxons worshipped in secret   
on the summit of the ,brocken1 when     
,christianity was extending her         
benignant sway over the subjacent       
plains4    ,as the locality of these    
idolatrous rites1 the ,brocken must have

 been  much frequented1 and we can      
scarcely doubt that the spectre which   
now  so often haunts it at sunrise must 
have been observed from the earliest    
times2 but it is nowhere mentioned that 
this phenomenon was in any  way         
associated with the objects of their    
idolatrous worship4 ,one of  the best   
accounts of the spectre of the ,brocken 
is that which is given  by ,m4 ,haue1   
who saw it on the #bcrd of ,may1 #agig4 
,after having been on  the summit of the
 mountain no less than thirty times1 he 
had at last  the good fortune of        
witnessing the object of his curiosity4 
,the sun  rose about four o'clock in the
 morning through a serene atmosphere4   
,in the south-west1 towards             
,achtermannshohe1 a brisk west wind     
carried  before it the transparent      
vapours1 which had not yet been         
condensed  into thick heavy clouds4     
,about a quarter past four he went      
towards the  inn1 and looked round to   
see whether the atmosphere would afford 

him a  free prospect towards the        
south-west1 when he observed at a very  
great  distance1 towards                
,achtermannshohe1 a human figure of a   
monstrous size4  ,his hat having been   
almost carried away by a violent gust of
 wind1  he suddenly raised his hand to  
his head to protect his hat1 and the    
colossal figure did the same4 ,he       
immediately made another movement by    
bending his body1--an action which was  
repeated by the spectral figure4  ,m4   
,haue was desirous of making further    
experiments1 but the figure             
disappeared4 ,he remained1 however1 in  
the same position1 expecting  its       
return1 and in a few minutes it again   
made its appearance on the              
,achtermannshohe1 when it mimicked his  
gestures as before4 ,he then  called the
 landlord of the inn1 and having both   
taken the same position  which he had   
before1 they looked towards the         
,achtermannshohe1 but saw  nothing4 ,in 
a very short space of time1 however1 two

 colossal figures  were formed over the 
above eminence1 and after bending their 
bodies  and imitating the gestures of   
the two spectators1 they disappeared4   
,retaining their position1 and keeping  
their eyes still fixed upon the  same   
spot1 the two gigantic spectres again   
stood before them1 and were  joined by a
 third4 ,every movement that they made  
was imitated by the  three figures1 but 
the effect varied in its intensity1     
being sometimes  weak and faint1 and at 
other times strong and well defined4    
,illustration3 ,fig4 #cj4    ,in the    
year #agih1 ,m4 ,jordan saw the same    
phenomenon at sunrise1 and  under       
similar circumstances1 but with less    
distinctness1 and without  any          
duplication of the figures4#ae     #ae  
,see ,j4 ,f4 ,gmelin's ,gottingischen   
,journal der ,wissenchaften1   vol4 i41 
part iii41 #agih4    ,phenomena         
perfectly analogous to the preceding1   
though seen under less  imposing        
circumstances1 have been often          

witnessed4 ,when the spectator  sees his
 own shadow opposite to the sun upon a  
mass of thin fleecy  vapour passing near
 him1 it not only imitates all his      
movements1 but  its head is distinctly  
encircled with a halo of light4 ,the    
arial  figure is often not larger than  
life1 its size and its apparent         
distance depending1 as we shall         
afterwards see1 upon particular causes4 
,i have often seen a similar shadow when
 bathing in a bright summer's  day in an
 extensive pool of deep water4 ,when the
 fine mud deposited  at the bottom of   
the pool is disturbed by the feet of the
 bather1 so  as to be disseminated      
through the mass of water in the        
direction of  his shadow1 his shadow is 
no longer a shapeless mass formed upon  
the  bottom1 but is a regular figure    
formed upon the floating particles of   
mud1 and having the head surrounded with
 a halo1 not only luminous1 but         
consisting of distinct radiations4      
,one of the most interesting accounts of

 arial spectres with which we  are      
acquainted has been given by ,mr4 ,james
 ,clarke1 in his ,survey of the  ,lakes 
of ,cumberland1 and the accuracy of this
 account was confirmed by  the          
attestations of two of the persons by   
whom the phenomena were first  seen4 ,on
 a summer's evening1 in the year #agdc1 
when ,daniel ,stricket1  servant to     
,john ,wren1 of ,wilton ,hall1 was      
sitting at the door along  with his     
master1 they saw the figure of a man    
with a dog pursuing some  horses along  
,souterfell-side1 a place so extremely  
steep1 that a horse  could scarcely     
travel upon it at all4 ,the figures     
appeared to run at  an amazing pace1    
till they got out of sight at the lower 
end of the  ,fell4 ,on the following    
morning1 ,stricket and his master       
ascended the  steep side of the         
mountain1 in the full expectation of    
finding the man  dead1 and of picking up
 some of the shoes of the horses1 which 
they  thought must have been cast while 

galloping at such a furious rate4       
,their expectations1 however1 were      
disappointed4 ,no traces1 either of  man
 or horse1 could be found1 and they     
could not even discover upon the  turf  
the single mark of a horse's hoof4      
,these strange appearances seen  at the 
same time by two different persons in   
perfect health1 could not  fail to make 
a deep impression on their minds4 ,they 
at first concealed  what they had seen1 
but they at length disclosed it1 and    
were laughed  at for their credulity4   
,in the following year1 on the #bcrd    
,june1 #agdd1 ,daniel ,stricket1 who    
was then servant to ,mr4 ,lancaster1 of 
,blakehills1 7a place near  ,wilton     
,hall1 and both of which places are only
 about half a mile  from ,souterfell17  
was walking1 about seven o'clock in the 
evening1  a little above the house1 when
 he saw a troop of horsemen riding  on  
,souterfell-side1 in pretty close ranks1
 and at a brisk pace4  ,recollecting the
 ridicule that had been cast upon him   

the preceding  year1 he continued to    
observe the figures for some time in    
silence2  but being at last convinced   
that there could be no deception in the 
matter1 he went to the house1 and       
informed his master that he had         
something curious to show him4 ,they    
accordingly went out together2 but      
before ,stricket had pointed out the    
place1 ,mr4 ,lancaster's son had        
discovered the arial figures4 ,the      
family was then summoned to the  spot1  
and the phenomena were seen alike by    
them all4 ,the equestrian  figures      
seemed to come from the lowest parts of 
,souterfell1 and became  visible at a   
place called ,knott4 ,they then advanced
 in regular troops  along the side of   
the ,fell1 till they came opposite to   
,blakehills1 when  they went over the   
mountain1 after describing a kind of    
curvilineal  path4 ,the pace at which   
the figures moved was a regular swift   
walk1  and they continued to be seen for
 upwards of two hours1 the approach  of 

darkness alone preventing them from     
being visible4 ,many troops  were seen  
in succession2 and frequently the last  
but one in a troop  quitted his         
position1 galloped to the front1 and    
took up the same pace  with the rest4   
,the changes in the figures were seen   
equally by all  the spectators1 and the 
view of them was not confined to the    
farm of  ,blakehills only1 but they were
 seen by every person at every cottage  
within the distance of a mile1 the      
number of persons who saw them          
amounting to about twenty-six4 ,the     
attestation of these facts1 signed  by  
,lancaster and ,stricket1 bears the date
 of the #bast ,july1 #aghe4    ,these   
extraordinary sights were received not  
only with distrust1 but  with absolute  
incredulity4 ,they were not even        
honoured with a place in  the records of
 natural phenomena1 and the philosophers
 of the day were  neither in possession 
of analogous facts1 nor were they       
acquainted with  those principles of    

atmospherical refraction upon which they
 depend4  ,the strange phenomena1       
indeed1 of the ,fata ,morgana1 or the   
,castles  of the ,fairy ,morgana1 had   
been long before observed1 and had been 
described by ,kircher in the #agth      
century1 but they presented nothing  so 
mysterious as the arial troopers of     
,souterfell2 and the general  characters
 of the two phenomena were so unlike1   
that even a philosopher  might have been
 excused for ascribing them to different
 causes4    ,this singular exhibition   
has been frequently seen in the straits 
of  ,messina1 between ,sicily and the   
coast of ,italy1 and whenever it takes  
place1 the people1 in a state of        
exultation1 as if it were not only  a   
pleasing but a lucky phenomenon1 hurry  
down to the sea1 exclaiming  ,morgana1  
,morgana6 ,when the rays of the rising  
sun form an angle  of #de on the sea of 
,reggio1 and when the surface of the    
water is  perfectly unruffled1 either by
 the wind or the current1 a spectator   

placed upon an eminence in the city1 and
 having his back to the sun  and his    
face to the sea1 observes upon the      
surface of the water superb  palaces1   
with their balconies and windows1 lofty 
towers1 herds and  flocks grazing in    
wooded valleys and fertile plains2      
armies of men  on horseback and on foot1
 with multiplied fragments of buildings1
  such as columns1 pilasters1 and       
arches4 ,these objects pass rapidly in  
succession along the surface of the sea 
during the brief period of  their       
appearance4 ,the various objects thus   
enumerated are pictures  of palaces and 
buildings actually existing on shore1   
and the living  objects are of course   
only seen when they happen to form a    
part of the  general landscape4    ,if1 
at the time that these phenomena are    
visible1 the atmosphere is  charged with
 vapour or dense exhalations1 the same  
objects which are  depicted upon the sea
 will be seen also in the air1 occupying
 a space  which extends from the surface

 to the height of twenty-five feet4     
,these  images1 however1 are less       
distinctly delineated than the former4  
,if the air is in such a state as to    
deposit dew1 and is capable of  forming 
the rainbow1 the objects will be seen   
only on the surface of  the sea2 but    
they all appear fringed with red1       
yellow1 and blue light1  as if they were
 seen through a prism4    ,in our own   
country1 and in our own times1 facts    
still more  extraordinary have been     
witnessed4 ,from ,hastings1 on the coast
 of  ,sussex1 the cliffs on the ,french 
coast are fifty miles distant1  and they
 are actually hid by the convexity of   
the earth2 that is1  a straight line    
drawn from ,hastings to the ,french     
coast would pass  through the sea4 ,on  
,wednesday1 the #bfth of ,july1 #agih1  
about five  o'clock in the afternoon1   
,mr4 ,latham1 a ,fellow of the ,royal   
,society1  then residing at ,hastings1  
was surprised to see a crowd of people  
running to the sea-side4 ,upon inquiry  

into the cause of this1 he  learned that
 the coast of ,france could be seen by  
the naked eye1 and  he immediately went 
down to witness so singular a sight4 ,he
 distinctly  saw the cliffs extending   
for some leagues along the ,french      
coast1 and  they appeared as if they    
were only a few miles off4 ,they        
gradually  appeared more and more       
elevated1 and seemed to approach nearer 
to the  eye4 ,the sailors with whom ,mr4
 ,latham walked along the waters edge   
were  at first unwilling to believe in  
the reality of the appearance2 but  they
 soon became so thoroughly convinced of 
it1 that they pointed out  and named to 
him the different places which they had 
been accustomed to  visit1 and which    
they conceived to be as near as if they 
were sailing  at a small distance into  
the harbour4 ,these appearances         
continued for  nearly an hour1 the      
cliffs sometimes appearing brighter and 
nearer1 and  at other times fainter and 
more remote4 ,mr4 ,latham then went upon

 the  eastern cliff or hill1 which is of
 considerable height1 when1 as he       
remarks1 a most beautiful scene         
presented itself to his view4 ,he beheld
  at once ,dungeness1 ,dover cliffs1 and
 the ,french coast all along from       
,calais1 ,boulogne1 c41 to ,st4         
,vallery1 and1 as some of the fishermen 
affirmed1 as far west as ,dieppe4 ,with 
the help of a telescope1 the  ,french   
fishing-boats were plainly seen at      
anchor1 and the different  colours of   
the land upon the heights1 together with
 the buildings1 were  perfectly         
discernible4 ,mr4 ,latham likewise      
states that the cape of land  called    
,dungeness1 which extends nearly two    
miles into the sea1 and is  about       
sixteen miles in a straight line from   
,hastings1 appeared as if  quite close  
to it1 and the vessels and fishing-boats
 which were sailing  between the two    
places appeared equally near1 and were  
magnified to  a high degree4 ,these     
curious phenomena continued 8in the     

highest  splendour0 till past eight     
o'clock1 although a black cloud had for 
some  time totally obscured the face of 
the sun4    ,a phenomenon no less       
marvellous was seen by ,professor       
,vince1 of  ,cambridge1 and another     
gentleman1 on the #fth of ,august1      
#ahjf1 at  ,ramsgate4 ,the summits v w x
 y of the four turrets of ,dover ,castle
  are usually seen over the hill ,,ab1  
upon which it stands1 lying between     
,ramsgate and ,dover2 but on the day    
above-mentioned1 at seven o'clock in    
the evening1 when the air was very still
 and a little hazy1 not only  were the  
tops v w x y of the four towers of      
,dover ,castle seen over  the adjacent  
hill ,,ab1 but the whole of the ,castle1
 m n r s1 appeared  as if it were       
situated on the side of the hill next   
,ramsgate1 and  rising above the hill as
 much as usual4 ,this phenomenon was so 
very  singular and unexpected1 that at  
first sight ,dr4 ,vince thought it an   
illusion2 but upon continuing his       

observations1 he became satisfied  that 
it was a real image of the ,castle4     
,upon this he gave a telescope  to a    
person present1 who1 upon attentive     
examination1 saw also a  very clear     
image of the ,castle as the ,doctor had 
described it4 ,he  continued to observe 
it for about twenty minutes1 during     
which time the  appearance remained     
precisely the same2 but rain coming on1 
they were  prevented from making any    
further observations4 ,between the      
observers  and the land from which the  
hill rises there was about six miles of 
sea1 and from thence to the top of the  
hill there was about the same  distance4
 ,their own height above the surface of 
the water was about  seventy feet4      
,illustration3 ,fig4 #ca4    ,this      
illusion derived great force from the   
remarkable circumstance1  that the hill 
itself did not appear through the image1
 as it might have  been expected to do4 
,the image of the castle was very strong
 and well  defined1 and though the rays 

from the hill behind it must undoubtedly
  have come to the eye1 yet the strength
 of the image of the castle so  far     
obscured the background1 that it made no
 sensible impression on the  observers4 
,their attention was of course          
principally directed to the  image of   
the castle2 but if the hill behind had  
been at all visible1  ,dr4 ,vince       
conceives that it could not have escaped
 their observation1  as they continued  
to look at it for a considerable time   
with a good  telescope4                 
,illustration3 ,fig4 #cb4    ,hitherto  
our arial visions have been seen only in
 their erect and  natural positions1    
either projected against the ground or  
elevated  in the air2 but cases have    
occurred in which both erect and        
inverted  images of objects have been   
seen in the air1 sometimes singly1      
sometimes combined1 sometimes when the  
real object was invisible1 and          
sometimes when a part of it had begun to
 show itself to the spectator4    ,in   

the year #agic1 ,mr4 ,huddart1 when     
residing at ,allonby1 in ,cumberland1   
perceived the inverted image of a ship  
beneath the image1 as shown  in ,fig4   
#cb2 but ,dr4 ,vince1 who afterwards    
observed this phenomenon  under a       
greater variety of forms1 found that the
 ship1 which was here  considered the   
real one1 was only an erect image of the
 real ship1  which was at that time     
beneath the horizon1 and wholly         
invisible4    ,illustration3 ,fig4 #cc4 
,in ,august1 #agih1 ,dr4 ,vince observed
 a great variety of these arial  images 
of vessels approaching the horizon4     
,sometimes there was seen  only one     
inverted image above the real ship1 and 
this was generally the  case when the   
real ship was full in view4 ,but when   
the real ship was  just begin beginning 
to show its top-mast above the horizon1 
as at ,a1  ,fig4 #cc1 two arial images  
of it were seen1 one at ,b inverted1 and
 the  other in its natural position at  
,c4 ,in this case the sea was distinctly

  visible between the erect and inverted
 images1 but in other cases the  hull of
 the one image was immediately in       
contact with the hull of the  other4    
,analogous phenomena were seen by       
,captain ,scoresby when navigating  with
 the ship ,baffin the icy sea in the    
immediate neighbourhood of  ,west       
,greenland4 ,on the #bhth of ,june1     
#ahbj1 he observed about eighteen  sail 
of ships at the distance of ten or      
fifteen miles4 ,the sun had  shone      
during the day without the interposition
 of a cloud1 and its  rays were         
peculiarly powerful4 ,the intensity of  
its light occasioned a  painful         
sensation in the eyes1 while its heat   
softened the tar in the  rigging of the 
ship1 and melted the snow on the        
surrounding ice with  such rapidity that
 pools of fresh water were formed on    
almost every  place1 and thousands of   
rills carried the excess into the sea4  
,there  was scarcely a breath of wind3  
the sea was as smooth as a mirror4 ,the 

surrounding ice was crowded together1   
and exhibited every variety1 from  the  
smallest lumps to the most magnificent  
sheets4 ,bears traversed the  fields and
 floes in unusual numbers1 and many     
whales sported in the  recesses and     
openings among the drift ice4 ,about six
 in the evening1 a  light breeze at     
,n4,w4 having sprung up1 a thin stratus 
or 8fog bank10  at first considerably   
illuminated by the sun1 appeared in the 
same  quarter1 and gradually rose to the
 altitude of about a quarter of a       
degree4 ,at this time most of the ships 
navigating at the distance  of ten or   
fifteen miles began to change their form
 and magnitude1  and when examined by a 
telescope from the mast-head1 exhibited 
some  extraordinary appearances1 which  
differed at almost every point of the   
compass4 ,one ship had a perfect image1 
as dark and distinct as the  original1  
united to its mast-head in a reverse    
position4 ,two others  presented two    
distinct inverted images in the air1 one

 of them a  perfect figure of the       
original1 and the other wanting the     
hull4 ,two  or three more were strangely
 distorted1 their masts appearing of at 
least twice their proper height1 the    
top-gallant mast forming one-half  of   
the total elevation2 and other vessels  
exhibited an appearance  totally        
different from all the preceding1 being 
as it were compressed1  in place of     
elongated4 ,their masts seemed to be    
scarcely one-half of  their proper      
altitude1 in consequence of which one   
would have supposed  that they were     
greatly heeled-to one side1 or in the   
position called  careening4 ,along with 
all the images of the ships a reflexion 
of the  ice1 sometimes in two strata1   
also appeared in the air1 and these     
reflexions suggested the idea of cliffs 
composed of vertical columns of         
alabaster4    ,on the #aeth1 #afth1 and 
#agth of the same month1 ,mr4 ,scoresby 
observed  similar phenomena1 sometimes  
extending continuously through half the 

circumference of the horizon1 and at    
other times appearing only in  detached 
spots in various quarters4 ,the inverted
 images of distant  vessels were often  
seen in the air1 while the ships        
themselves were  far beyond the reach of
 vision4 ,some ships were elevated to   
twice  their proper height1 while others
 were compressed almost to a line4      
,hummocks of ice were surprisingly      
enlarged1 and every prominent object  in
 a proper position was either magnified 
or distorted4    ,but of all the        
phenomena witnessed by ,mr4 ,scoresby1  
that of the  ,enchanted ,coast1 as it   
may be called1 must have been the most  
remarkable4 ,this singular effect was   
seen on the #ahth of ,july1 when  the   
sky was clear1 and a tremulous and      
perfectly transparent vapour  was       
particularly sensible and profuse3 at   
nine o'clock in the morning1  when the  
phenomenon was first seen1 the          
thermometer stood at #db  ,fahr42 but in
 the preceding evening it must have been

 greatly lower1  as the sea was in many 
places covered with a considerable      
pellicle  of new ice1--a circumstance1  
which1 in the very warmest time of the  
year1 must be considered as quite       
extraordinary1 especially when it  is   
known that #aj farther to the north no  
freezing of the sea at  this season had 
ever before been observed4 ,having      
approached on this  occasion so near the
 unexplored shore of ,greenland that the
 land  appeared distinct and bold1 ,mr4 
,scoresby was anxious to obtain a       
drawing of it2 but on making the attempt
 he found that the outline  was         
constantly changing1 and he was induced 
to examine the coast with  a telescope1 
and to sketch the various appearances   
which presented  themselves4 ,these are 
shown1 without any regard to their      
proper order1  in ,fig4 #cd1 which we   
shall describe in ,mr4 ,scoresby's own  
words3 8,the  general telescopic        
appearance of the coast was that of an  
extensive  ancient city abounding with  

the ruins of castles1 obelisks1         
churches1  and monuments1 with other    
large and conspicuous buildings4 ,some  
of  the hills seemed to be surmounted by
 turrets1 battlements1 spires1  and     
pinnacles2 while others1 subjected to   
one or two reflexions1  exhibited large 
masses of rock1 apparently suspended in 
the air1 at a  considerable elevation   
above the actual termination of the     
mountains to  which they referred4 ,the 
whole exhibition was a grand            
phantasmagoria4  ,scarcely was any      
particular portion sketched before it   
changed its  appearance1 and assumed the
 form of an object totally different4   
,it  was perhaps alternately a castle1 a
 cathedral1 or an obelisk2 then         
expanding horizontally1 and coalescing  
with the adjoining hills1 united  the   
intermediate valleys1 though some miles 
in width1 by a bridge  of a single arch1
 of the most magnificent appearance and 
extent4  ,notwithstanding these repeated
 changes1 the various figures           

represented  in the drawing had all the 
distinctness of reality2 and not only   
the  different strata1 but also the     
veins of the rocks1 with the wreaths of 
snow occupying ravines and fissures1    
form sharp and distinct lines1  and     
exhibited every appearance of the most  
perfect solidity40    ,illustration3    
,fig4 #cd4    ,one of the most          
remarkable facts respecting arial images
 presented  itself to ,mr4 ,scoresby in 
a later voyage which he performed to the
  coast of ,greenland in #ahbb4 ,having 
seen an inverted image of a ship  in the
 air1 he directed to it his telescope2  
he was able to discover  it to be his   
father's ship1 which was at the time    
below the horizon4  8,it was10 says he1 
8so well defined1 that ,i could         
distinguish by a  telescope every sail1 
the general rig of the ship1 and its    
particular  character2 insomuch1 that ,i
 confidently pronounced it to be my     
father's  ship1 the ,fame1 which it     
afterwards proved to be2 though1 on     

comparing notes with my father1 ,i found
 that our relative position1 at  the    
time1 gave a distance from one another  
very nearly thirty miles1  being about  
seventeen miles beyond the horizon1 and 
some leagues beyond  the limit of direct
 vision4 ,i was so struck with the      
peculiarity of  the circumstance1 that  
,i mentioned it to the officer of the   
watch1  stating my full conviction that 
the ,fame was then cruising in the      
neighbouring inlet40    ,several curious
 effects of the mirage were observed by 
,baron ,humboldt  during his travels in 
,south ,america4 ,when he was residing  
at ,cumana1  he frequently saw the      
islands of ,picuita and ,boracha        
suspended in the  air1 and sometimes    
with an inverted image4 ,on one occasion
 he observed  small fishing-boats       
swimming in the air1 during more than   
three or  four minutes1 above the       
well-defined horizon of the sea2 and    
when they  were viewed through a        
telescope1 one of the boats had an      

inverted  image accompanying it in its  
movements4 ,this distinguished traveller
  observed similar phenomena in the     
barren steppes of the ,caraccas1 and  on
 the borders of the ,orinoco1 where the 
river is surrounded by sandy  plains4   
,little hills and chains of hills       
appeared suspended in the  air1 when    
seen from the steppes1 at three or four 
leagues' distance4  ,palm-trees standing
 single in the ,llanos appeared to be   
cut off at  bottom1 as if a stratum of  
air separated them from the ground2 and1
 as  in the ,african desert1 plains     
destitute of vegetation appeared to be  
rivers or lakes4 ,at the ,mesa de       
,pavona ,m4 ,humboldt and ,m4 ,bonpland 
saw  cows suspended in the air at the   
distance of #ajjj toises1 and having    
their feet elevated #c' #bj0 above the  
soil4 ,in this case the images were     
erect1 but the travellers learned from  
good authority that inverted  images of 
horses had been seen suspended in the   
air near ,calabozo4    ,in all these    

cases of arial spectres1 the images were
 directly above  the real object2 but a 
curious case was observed by ,messrs4   
,jurine and  ,soret on the #agth        
,september1 #ahah1 where the image of   
the vessel was  on one side of the real 
one4 ,about #aj ,p4,m4 a barque at the  
distance  of about #djjj toises from    
,bellerive1 on the lake of ,geneva1 was 
seen  approaching to ,geneva by the left
 bank of the lake1 and at the same  time
 an image of the sails was observed     
above the water1 which1 instead  of     
following the direction of the barque1  
separated from it1 and  appeared to     
approach ,geneva by the right bank of   
the lake1 the image  moving from east to
 west1 while the barque moved from north
 to  south4 ,when the image first       
separated from the barque they had both 
the same magnitude1 but the image       
diminished as it receded from it1  and  
was reduced to one-half when the        
phenomenon disappeared4    ,a very      
unusual example of arial spectres       

occurred to ,dr4 ,a4 ,p4 ,buchan  while 
walking on the cliff about a mile to the
 east of ,brighton1 on the  morning of  
the #bhth of ,november1 #ahjd4 8,while  
watching the rising of  the sun10 says  
he1 8,i turned my eyes directly towards 
the sea1 just as  the solar disk emerged
 from the surface of the water1 and saw 
the face  of the cliff on which ,i was  
standing represented precisely opposite 
to  me at some distance on the ocean4   
,calling the attention of my companion  
to this appearance1 we discerned our own
 figures standing on the summit  of the 
apparent opposite cliff1 as well as the 
representation of the  windmill near at 
hand4    8,the reflected images were    
most distinct precisely opposite to     
where  we stood1 and the false cliff    
seemed to fade away1 and to draw near   
to the real one1 in proportion as it    
receded towards the west4 ,this         
phenomenon lasted about ten minutes1 or 
till the sun had risen nearly  his own  
diameter above the surface of the ocean4

 ,the whole then seemed  to be elevated 
into the air1 and successively          
disappeared1 giving an  impression very 
similar to that which is produced by the
 drawing up of  a drop-scene in a       
theatre4 ,the horizon was cloudy1 or    
perhaps it might  with more propriety be
 said that the surface of the sea was   
covered  with a dense fog of many yards 
in height1 and which gradually receded  
before the rays of the sun40    ,an     
illusion of a different kind1 though not
 less interesting1 is  described by the 
,rev4 ,mr4 ,hughes in his ,travels in   
,greece1 as seen  from the summit of    
,mount tna4 8,i must not forget to      
mention10 says  he1 8one extraordinary  
phenomenon1 which we observed1 and for  
which ,i  have searched in vain for a   
satisfactory solution4 ,at the extremity
  of the vast shadow which tna projects 
across the island1 appeared a  perfect  
and distinct image of the mountain      
itself elevated above the  horizon1 and 
diminished as if viewed in a concave    

mirror4 ,where or what  the reflector   
could be which exhibited this image1 ,i 
cannot conceive2  we could not be       
mistaken in its appearance1 for all our 
party observed  it1 and we had been     
prepared for it beforehand by our       
,catanian friends4  ,it remained visible
 about ten minutes1 and disappeared as  
the shadow  decreased4 ,mr4 ,jones      
observed the same phenomenon1 as well as
 some  other friends with whom ,i       
conversed upon the subject in ,england40
    ,it is impossible to study the      
preceding phenomena without being       
impressed with the conviction1 that     
nature is full of the marvellous1  and  
that the progress of science and the    
diffusion of knowledge  are alone       
capable of dispelling the fears which   
her wonders must  necessarily excite    
even in enlightened minds4 ,when a      
spectre haunts  the couch of the sick1  
or follows the susceptible vision of the
  invalid1 a consciousness of           
indisposition divests the apparition of 

much of its terror1 while its           
invisibility to surrounding friends     
soon stamps it with the impress of a    
false perception4 ,the spectres  of the 
conjuror1 too1 however skilfully they   
may be raised1 quickly  lose their      
supernatural character2 and even the    
most ignorant beholder  regards the     
modern magician as but an ordinary man1 
who borrows from  the sciences the best 
working implements of his art4 ,but     
when1 in the  midst of solitude1 and in 
situations where the mind is undisturbed
  by sublunary cares1 we see our own    
image delineated in the air1 and        
mimicking in gigantic perspective the   
tiny movements of humanity2--when  we   
see troops in military array performing 
their evolutions on the very  face of an
 almost inaccessible precipice--when1 in
 the eye of day1 a  mountain seems to   
become transparent1 and exhibits on one 
side of it a  castle which we know to   
exist only on the other2 when distant   
objects1  concealed by the roundness of 

the earth1 and beyond the cognisance of 
the telescope1 are actually transferred 
over the intervening convexity  and     
presented in distinct and magnified     
outline to our accurate                 
examination2--when such varied and      
striking phantasms are seen also by  all
 around us1 and therefore appear in the 
character of real phenomena  of nature1 
our impressions of supernatural agency  
can only be removed  by a distinct and  
satisfactory knowledge of the causes    
which gave them  birth4    ,it is only  
within the last forty years that science
 has brought these  atmospherical       
spectres within the circle of her       
dominion2 and not only  are all their   
phenomena susceptible of distinct       
explanation1 but we can  even reproduce 
them on a small scale with the simplest 
elements of our  optical apparatus4     
,illustration3 ,fig4 #ce4    ,in order  
to convey a general idea of the causes  
of these phenomena1 let  ,,abcd1 ,fig4  
#ce1 be a glass trough filled with      

water1 and let a small  ship be placed  
at ,s4 ,an eye situated about ,e1 will  
see the top-mast  of the ship ,s1       
directly through the plate of glass     
,,bd4 ,fix a convex  lens a of short    
focus upon the plate of glass ,,bd1 and 
a little above  a straight line ,,se    
joining the ship and the eye2 and       
immediately above  the convex lens a    
place a concave one b4 ,the eye will now
 see1  through the convex lens a1 an    
inverted image of the ship at ,s1  and  
through the concave lens b1 an erect    
image of the ship at ,s1  representing  
in a general way the phenomena shown in 
,fig4 #cc4 ,but it  will be asked1 where
 are the lenses in nature to produce    
these effects8  ,this question is easily
 answered4 ,if we take a tin tube with  
glass  plates at each end1 and fill it  
with water1 and if we cool it on the    
outside with ice1 it will act like a    
concave lens when the cooling  effect   
has reached the axis2 and1 on the other 
hand1 if we heat the  same tube filled  

with water1 on the outside1 it will act 
as a convex  glass4 ,in the first case  
the density of the water diminishes     
towards  the centre1 and in the second  
it increases towards the centre4 ,the   
very same effects are produced in the   
air1 only a greater tract of air  is    
necessary for showing the effect        
produced1 by heating and cooling it     
unequally4 ,if we now remove the lenses 
a1 b1 and hold a heated iron            
horizontally above the water in the     
trough ,,abc1 the heat will gradually   
descend1 expanding or rendering rarer   
the upper portions of the fluid4  ,if1  
when the heat has reached within a      
little of the bottom1 we look  through  
the trough at the ship ,s in the        
direction ,,es1 we shall see  an        
inverted image at ,s1 and an erect one  
at ,s2 and if we hide from  the eye at  
,e all the ship ,s1 excepting the       
top-mast1 we shall have an  exact       
representation of the phenomenon in     
,fig4 #cc4 ,the experiment will  succeed

 better with oil in place of water2 and 
the same result may be  obtained without
 heat1 by pouring clear syrup into the  
glass trough  till it is nearly         
one-third full1 and then filling it up  
with water4  ,the water will gradually  
incorporate with the syrup1 and produce1
 as  ,dr4 ,wollaston has shown1 a       
regular gradation of density1           
diminishing  from that of the pure syrup
 to that of the pure water4 ,similar    
effects  may be obtained by using masses
 of transparent solids1 such as glass1  
rock-salt1 c4    ,now it is easy to     
conceive how the changes of density     
which we can  thus produce artificially 
may be produced in nature4 ,if1 in      
serene  weather1 the surface of the sea 
is much colder than the air of the      
atmosphere1 as it frequently is1 and as 
it was to a very great degree  during   
the phenomena described by ,mr4         
,scoresby1 the air next the sea  will   
gradually become colder and colder1 by  
giving out its heat to  the water2 and  

the air immediately above will give out 
its heat to  the cooler air immediately 
below it1 so that the air from the      
surface  of the sea1 to a considerable  
height upwards1 will gradually diminish 
in density1 and therefore must produce  
the very phenomena we have  described4  
,illustration3 ,fig4 #cf4    ,the       
phenomenon of ,dover ,castle seen on the
 ,ramsgate side of the hill1  was       
produced by the air being more dense    
near the ground and above the  sea than 
at greater heights1 and hence the rays  
proceeding from the  castle reached the 
eye in curve lines1 and the cause of its
 occupying  its natural position on the 
hill1 and not being seen in the air1 was
  that the top of the hill itself1 in   
consequence of being so near the        
castle1 suffered the same change from   
the varying density of the  air1 and    
therefore the castle and the hill were  
equally elevated and  retained their    
relative positions4 ,the reason why the 
image of the  castle and hill appeared  

erect was1 that the rays from the top   
and  bottom of the castle had not       
crossed before they reached ,ramsgate2  
but  as they met at ,ramsgate1 an eye at
 a greater distance from the castle1    
and in the path of the rays1 would have 
seen the image inverted4 ,this  will be 
better understood from the preceding    
diagram1 which represents  the actual   
progress of the rays1 from a ship ,,sp1 
concealed from the  observer at ,e by   
the convexity of the earth ,,pqe4 ,a ray
 proceeding from  the keel of the ship  
,p is refracted into the curve line ,p c
 x c ,e1  and a ray proceeding from the 
top-mast ,s1 is refracted in the        
direction  ,s d x d ,e1 the two rays    
crossing at x1 and proceeding to the eye
  ,e with the ray from the keel ,p      
uppermost2 hence the ship must appear   
inverted as at s p4 ,now if the eye ,e  
of the observer had been placed  nearer 
the ship as at x1 before the rays       
crossed1 as was the case at  ,ramsgate1 
it would have seen an erect image of the

 ship raised a little  above the real   
ship ,,sp4 ,rays ,s m1 ,s n1 proceeding 
higher up in the  air1 are refracted in 
the directions ,s m m ,e1 ,s n n ,e1 but
 do not  cross before they reach the    
eye1 and therefore they afford the erect
  image of the ship shown at s p4       
,the arial troopers seen at ,souterfell 
were produced by the very  same process 
as the spectre of ,dover ,castle1 having
 been brought by  unequal refraction    
from one side of the hill to the other4 
,it is not  our business to discover how
 a troop of soldiers came to be         
performing  their evolutions on the     
other side of ,souterfell2 but if there 
was then  no road along which they could
 be marching1 it is highly probable that
  they were troops exercising among the 
hills in secret1 previously to  the     
breaking out of the rebellion in #agde4 
,the image of the ,genevese barque which
 was seen sailing at a distance  from   
the real one1 arose from the same cause 
as the images of ships in  the air2 with

 this difference only1 that in this case
 the strata of  equal density were      
vertical or perpendicular to the water1 
whereas1  in the former cases they were 
horizontal or parallel to the water4    
,the state of the air which produced the
 lateral image may be produced  by a    
headland or island1 or even rocks1 near 
the surface1 and covered  with water4   
,these headlands1 islands1 or sunken    
rocks being powerfully  heated by the   
sun in the daytime1 will heat the air   
immediately above  them1 while the      
adjacent air over the sea will retain   
its former  coolness and density4 ,hence
 there will necessarily arise a         
gradation  of density varying in the    
same horizontal direction1 or where the 
lines of equal density are vertical4 ,if
 we suppose the very same state  of the 
air to exist in a horizontal plane which
 exists in a vertical  plane1 in ,fig4  
#cf1 then the same images would be seen 
in a horizontal  line1 viz41 an inverted
 one at s p1 and an erect one at sp4 ,in

  the case of the ,genevese barque1 the 
rays had not crossed before they        
reached the eye1 and therefore the image
 was an erect one4 ,had the  real       
,genevese barque been concealed by some 
promontory or other cause  from the     
observation of ,messrs4 ,jurine and     
,soret1 they might have  attached a     
supernatural character to the spectral  
image1 especially if  they had seen it  
gradually decay1 and finally disappear  
on the still  and unbroken surface of   
the lake4 ,no similar fact had been     
previously  observed1 and there were no 
circumstances in the case to have       
excited  the suspicion that it was the  
spectre of a real vessel produced by    
unequal refraction4    ,the spectre of  
the ,brocken and other phenomena of the 
same kind1 have  essentially a different
 origin from those which arise from     
unequal  refraction4 ,they are merely   
shadows of the observer projected on    
dense  vapour or thin fleecy clouds1    
which have the power of reflecting much 

light4 ,they are seen most frequently at
 sunrise1 because it is at that  time   
that the vapours and clouds necessary   
for their production are  most likely to
 be generated2 and they can be seen only
 when the sun  is throwing his rays     
horizontally1 because the shadow of the 
observer  would otherwise be thrown     
either up in the air1 or down upon the  
ground4 ,if there are two persons       
looking at the phenomenon1 as when  ,m4 
,haue and the landlord saw it together1 
each observer will see his  own image   
most distinctly1 and the head will be   
more distinct than the  rest of the     
figure1 because the rays of the sun will
 be more copiously  reflected at a      
perpendicular incidence3 and as1 from   
this cause1 the  light reflected from   
the vapour or cloud becomes fainter     
farther from  the shadow1 the appearance
 of a halo round the head of the        
observer is  frequently visible4 ,m4    
,haue mentions the extraordinary        
circumstance  of the two spectres of him

 and the landlord being joined by a     
third  figure1 but he unfortunately does
 not inform us which of the two  figures
 was doubled1 for it is impossible that 
a person could have  joined their party 
unobserved4 ,it is very probable that   
the new spectre  forms a natural        
addition to the group1 as we have       
represented it in  ,fig4 #cj2 and1 if   
this was the case1 it could only have   
been produced by  a duplication of one  
of the figures produced by unequal      
refraction4    ,the reflected spectre of
 ,dr4 ,buchan standing upon the cliff at
  ,brighton1 arose from a cause to which
 we have not yet adverted4 ,it was      
obviously no shadow1 for it is certain1 
from the locality1 that the  rays of the
 sun fell upon the face of the cliff and
 upon his person at  an angle of about  
#gc from the perpendicular1 so as to    
illuminate them  strongly4 ,now1 there  
are two ways in which such an image may 
have been  reflected1 namely1 either    
from strata of air of variable density1 

or  from a vertical stratum of vapour1  
consisting of exceedingly minute        
globules of water4 ,whenever light      
suffers refraction1 either in passing   
at once from one medium into another1 or
 from one part of the same  medium into 
another of different density1 a portion 
of it suffers  reflexion4 ,if an object1
 therefore1 were strongly illuminated1 a
  sufficiently distinct image1 or rather
 shadow of it1 might be seen by         
reflexion from strata of air of         
different density4 ,as the temperature  
at which moisture is deposited in the   
atmosphere varies with the  density of  
the air1 then at the same temperature   
moisture might be  depositing in a      
stratum of one density1 while no        
deposition is taking  place in the      
adjacent stratum of a different density4
 ,hence there would  exist1 as it were  
in the air1 a vertical wall or stratum  
of minute  globules of water1 from the  
surface of which a sufficiently distinct
  image of a highly illuminated object  

might be reflected4 ,that this  is      
possible may be proved by breathing upon
 glass4 ,if the particles  deposited    
upon the glass are large1 then no       
distinct reflection will  take place2   
but if the particles be very small1 we  
shall see a distinct  image formed by   
the surface of the aqueous film4    ,the
 phenomena of the ,fata ,morgana have   
been too imperfectly described  to      
enable us to offer a satisfactory       
explanation of them4 ,the arial  images 
are obviously those formed by unequal   
refraction4 ,the pictures  seen on the  
sea may be either the arial images      
reflected from its  surface1 or from a  
stratum of dense vapour1 or they may be 
the direct  reflexions from the objects 
themselves4 ,the coloured images1 as    
described by ,minasi1 have never been   
seen in any analogous phenomena1  and   
require to be better described before   
they can be submitted to  scientific    
examination4    ,the representation of  
ships in the air by unequal refraction  

has no  doubt given rise in early times 
to those superstitions which have       
prevailed in different countries        
respecting 8phantom ships10 as ,mr4     
,washington ,irving calls them1 which   
always sail in the eye of the  wind1 and
 plough their way through the smooth    
sea1 where there is  not a breath of    
wind upon its surface4 ,in his beautiful
 story of the  storm ship1 which makes  
its way up the ,hudson against wind and 
tide1  this elegant writer has finely   
embodied one of the most interesting    
superstitions of the early ,american    
colonists4 ,the ,flying ,dutchman had1  
in all probability1 a similar origin2   
and the wizard beacon-keeper of  the    
,isle of ,france1 who saw in the air the
 vessels bound to the island  long      
before they appeared in the offing1 must
 have derived his power  from a diligent
 observation of the phenomena of nature4
          ,,letter ,,vii4     ,illusions
 depending on the ear--,practised by the
 ancients--,speaking   and singing heads

 of the ancients--,exhibition of the    
,invisible ,girl   described and        
explained--,illusions arising from the  
difficulty   of determining the         
direction of sounds--,singular example  
of this   illusion--,nature of          
ventriloquism--,exhibitions of some of  
the   most celebrated                   
ventriloquists--,m4 ,st4 ,gille--,louis 
,brabant--,m4   ,alexandre--,capt4      
,lyon's account of ,esquimaux           
ventriloquists4      ,next to the eye1  
the ear is the most fertile source of   
our illusions1  and the ancient         
magicians seem to have been very        
successful in turning  to their purposes
 the doctrines of sound4 ,in the        
,labyrinth of ,egypt1  which contained  
twelve palaces and #aejj subterraneous  
apartments1 the  gods were made to speak
 in a voice of thunder2 and ,pliny1 in  
whose  time this singular structure     
existed1 informs us1 that some of the   
palaces were so constructed that their  
doors could not be opened  without      

permitting the peals of thunder to be   
heard in the interior4  ,when ,darius   
,hystaspes ascended the throne1 and     
allowed his subjects to  prostrate      
themselves before him as a god1 the     
divinity of his character  was impressed
 upon his worshippers by the bursts of  
thunder and flashes  of lightning which 
accompanied their devotion4 ,history has
 of course  not informed us how these   
effects were produced2 but it is        
probable  that1 in the subterraneous and
 vaulted apartments of the ,egyptian    
labyrinth1 the reverberated sounds      
arising from the mere opening and       
shutting of the doors themselves        
afforded a sufficient imitation of      
ordinary thunder4 ,in the palace of the 
,persian king1 however1 a more          
artificial imitation is likely to have  
been employed1 and it is not  improbable
 that the method used in our modern     
theatres was known to  the ancients4 ,a 
thin sheet of iron1 three or four feet  
long1 such as  that used for ,german    

stoves1 is held by one corner between   
the finger  and the thumb1 and allowed  
to hang freely by its own weight4 ,the  
hand  is then moved or shaken           
horizontally1 so as to agitate the      
corner in a  direction at right angles  
to the surface of the sheet4 ,by this   
simple  process a great variety of      
sounds may be produced1 varying from the
  deep growl of distant thunder to those
 loud and explosive bursts which  rattle
 in quick succession from clouds        
immediately over our heads4  ,the       
operator soon acquires great power over 
this instrument1 so as  to be able to   
produce from it any intensity and       
character of sound  that may be         
required4 ,the same effect may be       
produced by sheets of  tin-plate1 and by
 thin plates of mica2 but1 on account of
 their small  size1 the sound is shorter
 and more acute4 ,in modern exhibitions 
an  admirable imitation of lightning is 
produced by throwing the powder of      
rosin1 or the dust of lycopodium1       

through a flame2 and the rattling       
showers of rain which accompany these   
meteors are well imitated by a          
well-regulated shower of peas4    ,the  
principal pieces of acoustic mechanism  
used by the ancients were  speaking or  
singing heads1 which were constructed   
for the purpose  of representing the    
gods1 or of uttering oracular responses4
 ,among  these1 the speaking head of    
,orpheus1 which uttered its responses   
at ,lesbos1 is one of the most famous4  
,it was celebrated not only  throughout 
,greece1 but even in ,persia2 and it had
 the credit of  predicting1 in the      
equivocal language of the heathen       
oracles1 the  bloody death which        
terminated the expedition of ,cyrus the 
,great into  ,scythia4 ,odin1 the mighty
 magician of the ,north1 who imported   
into  ,scandinavia the magical arts of  
the ,east1 possessed a speaking head1   
said to be that of the sage ,minos1     
which he had enchased in gold1  and     
which uttered responses that had all the

 authority of a divine  revelation4 ,the
 celebrated mechanic ,gerbert1 who      
filled the papal chair  ,a4,d4 #ajjj1   
under the name of ,sylvester ,,ii41     
constructed a speaking  head of brass4  
,albertus ,magnus is said to have       
executed a head in  the thirteenth      
century1 which not only moved but spoke4
 ,it was made  of earthenware1 and      
,thomas ,aquinas is said to have been so
 terrified  when he saw it1 that he     
broke it in pieces2 upon which the      
mechanist  exclaimed1 8,there goes the  
labour of thirty years60    ,it has been
 supposed by some authors1 that in the  
ancient  speaking-machines the deception
 is effected by means of ventriloquism1 
the voice issuing from the juggler      
himself2 but it is more probable  that  
the sound was conveyed by pipes from a  
person in another apartment  to the     
mouth of the figure4 ,lucian1 indeed1   
expressly informs us1  that the impostor
 ,alexander made his figure of sculapius
 speak1 by  transmitting his voice      

through the gullet of a crane to the    
mouth of  the statue2 and that this     
method was general appears from a       
passage in  ,theodoretus1 who assures   
us1 that in the fourth century1 when    
,bishop  ,theophilus broke to pieces the
 statues at ,alexandria1 he found some  
which were hollow1 and which were so    
placed against a wall1 that the  priest 
could conceal himself behind them2 and  
address the ignorant  spectators through
 their mouths4    ,even in modern times1
 speaking-machines have been constructed
 on this  principle4 ,the figure is     
frequently a mere head placed upon a    
hollow  pedestal1 which1 in order to    
promote the deception1 contains a pair  
of  bellows1 a sounding-board1 a        
cylinder and pipes supposed to represent
  the organs of speech4 ,in other cases 
these are dispensed with1 and a  simple 
wooden head utters its sounds through a 
speaking trumpet4 ,at the  court of     
,charles ,,ii41 this deception was      
exhibited with great effect by  one     

,thomas ,irson1 an ,englishman2 and when
 the astonishment had become  very      
general1 a popish priest was discovered 
by one of the pages in  an adjoining    
apartment4 ,the questions had been      
proposed to the wooden  figure by       
whispering into its ear1 and this       
learned personage had  answered them all
 with great ability1 by speaking through
 a pipe in the  same language in which  
the questions were proposed4 ,professor 
,beckmann  informs us that children and 
women were generally concealed either in
  the juggler's box or in the adjacent  
apartment1 and that the juggler  gave   
them every assistance by means of signs 
previously agreed upon4  ,when one of   
these exhibitions was shown at          
,gttingen1 the ,professor  was allowed1 
on the promise of secrecy1 to witness   
the process of  deception4 ,he saw the  
assistant in another room1 standing     
before the  pipe with a card in his     
hand1 upon which the signs agreed upon  
had  been marked1 and he had been       

introduced so privately into the house  
that even the landlady was ignorant of  
his being there4    ,an exhibition of   
the very same kind has been brought     
forward in our  own day1 under the name 
of the ,invisible ,girl2 and as the     
mechanism  employed was extremely       
ingenious1 and is well fitted to convey 
an idea  of this class of deceptions1 we
 shall give a detailed description of   
it4    ,illustration3 ,fig4 #cg4    ,the
 machinery1 as constructed by ,m4       
,charles1 is shown in fig4 #cg in       
perspective1 and a plan of it in ,fig4  
#ch4 ,the four upright posts ,a1 ,a1    
,a1 ,a1 are united at top by a cross    
rail ,b1 ,b1 and by two similar rails   
at bottom4 ,four bent wires a1 a1 a1 a1 
proceeded from the top  of these posts1 
and terminated at c4 ,a hollow copper   
ball ,m1 about  a foot in diameter1 was 
suspended from these wires by four      
slender  ribands b1 b1 b1 b1 and into   
the copper ball were fixed the          
extremities of four trumpets ,t1 ,t1 ,t1

 ,t1 with their mouths outwards4        
,illustration3 ,fig4 #ch4    ,the       
apparatus now described was all that was
 visible to the spectator2  and though  
fixed in one spot1 yet it had the       
appearance of a piece of  separate      
machinery1 which might have occupied any
 other part of the  room4 ,when one of  
the spectators was requested by the     
exhibitor to  propose some question1 he 
did it by speaking into one of the      
trumpets  at ,t4 ,an appropriate answer 
was then returned from all the trumpets1
  and the sound issued with sufficient  
intensity to be heard by an ear  applied
 to any of them1 and yet it was so weak 
that it appeared to come  from a person 
of very diminutive size4 ,hence the     
sound was supposed to  come from an     
invisible girl1 though the real speaker 
was a full-grown  woman4 ,the invisible 
lady conversed in different languages1  
sang  beautifully1 and made the most    
lively and appropriate remarks on the   
persons in the room4    ,this exhibition

 was obviously far more wonderful than  
the speaking  heads which we have       
described1 as the latter invariably     
communicated  with a wall1 or with a    
pedestal through which pipes could be   
carried  into the next apartment4 ,but  
the ball ,m and its trumpets            
communicated  with nothing through which
 sound could be conveyed4 ,the spectator
  satisfied himself by examination that 
the ribands b1 b1 were real  ribands1   
which concealed nothing1 and which could
 convey no sound2 and  as he never      
conceived that the ordinary piece of    
frame-work ,,ab could  be of any other  
use than its apparent one of supporting 
the sphere ,m1  and defending it from   
the spectators1 he was left in utter    
amazement  respecting the origin of the 
sound1 and his surprise was increased   
by the difference between the sounds    
which were uttered and those of         
ordinary speech4    ,though the         
spectators were thus deceived by their  
own reasoning1  yet the process of      

deception was a very simple one4 ,in two
 of the  horizontal railings ,a1 ,a1    
,fig4 #ch1 opposite the trumpet mouths  
,t1  there was an aperture communicating
 with a pipe or tube which went  to the 
vertical post ,b1 and descending it1 as 
shown at ,,taa1 ,fig4 #ci1  went beneath
 the floor f f1 in the direction p p1   
and entered the  apartment ,n1 where the
 invisible lady sat4 ,on the side of the
 partition  about h1 there was a small  
hole through which the lady saw what was
  going on in the exhibition-room1 and  
communications were no doubt made  to   
her by signals from the person who      
attended the machine4 ,when one of  the 
spectators asked a question by speaking 
into one of the trumpets  ,t1 the sound 
was reflected from the mouth of the     
trumpet back to the  aperture at ,a1 in 
the horizontal rail1 ,fig4 #ch1 and was 
distinctly  conveyed along the closed   
tube into the apartment ,n4 ,in like    
manner the  answer issued from the      
aperture ,a1 and being reflected back to

 the ear  of the spectator by the       
trumpet1 he heard the sounds with that  
change  of character which they receive 
when transmitted through a tube and     
then reflected to the ear4              
,illustration3 ,fig4 #ci4    ,the       
surprise of the auditors was greatly    
increased by the circumstance1  that an 
answer was returned to questions put in 
a whisper1 and also  by the conviction  
that nobody but a person in the middle  
of the  audience could observe the      
circumstances to which the invisible    
figure  frequently adverted4            
,although the performances of speaking  
heads were generally effected  by the   
methods now described1 yet there is     
reason to think that the  ventriloquist 
sometimes presided at the exhibition1   
and deceived the  audience by his       
extraordinary powers of illusion4 ,there
 is no species  of deception more       
irresistible in its effects than that   
which arises  from the uncertainty with 
which we judge of the direction and     

distance  of sounds4 ,every person must 
have noticed how a sound in their own   
ears  is often mistaken for some loud   
noise moderated by the distance from    
which it is supposed to come2 and the   
sportsman must have frequently  been    
surprised at the existence of musical   
sounds humming remotely in  the extended
 heath1 when it was only the wind       
sounding in the barrel  of his gun4 ,the
 great proportion of apparitions that   
haunt old castles  and apartments       
associated with death1 exist only in the
 sounds which  accompany them4 ,the     
imagination even of the boldest inmate  
of a place  hallowed by superstition1   
will transfer some trifling sound near  
his  own person to a direction and to a 
distance very different from the  truth1
 and the sound which otherwise might    
have no peculiar complexion  will derive
 another character from its new         
locality4 ,spurning the idea  of a      
supernatural origin1 he determines to   
unmask the spectre1 and  grapple with it

 in its den4 ,all the inmates of the    
house are found  to be asleep--even the 
quadrupeds are in their lair--there is  
not a  breath of wind to ruffle the lake
 that reflects through the casement  the
 reclining crescent of the night2 and   
the massive walls in which he  is       
enclosed forbid the idea that he has    
been disturbed by the warping  of       
panelling or the bending of partitions4 
,his search is vain2 and  he remains    
master of his own secret1 till he has   
another opportunity  of investigation4  
,the same sound again disturbs him1 and1
 modified  probably by his own position 
at the time1 it may perhaps appear to   
come in a direction slightly different  
from the last4 ,his searches are        
resumed1 and he is again disappointed4  
,if this incident should recur  night   
after night with the same result--if the
 sound should appear to  depend upon his
 own motions1 or be any how associated  
with himself1  with his present         
feelings1 or with his past history1 his 

personal  courage will give way2 a      
superstitious dread1 at which he himself
  perhaps laughs1 will seize his mind2  
and he will rather believe that  the    
sounds have a supernatural origin1 than 
that they could continue to  issue from 
a spot where he knows there is no       
natural cause for their  production4    
,i have had occasion to have personal   
knowledge of a case much  stronger than 
that which has now been put4 ,a         
gentleman1 devoid of all  superstitious 
feelings1 and living in a house free    
from any gloomy  associations1 heard    
night after night in his bed-room a     
singular noise1  unlike any ordinary    
sound to which he was accustomed4 ,he   
had slept in  the same room for years   
without hearing it1 and he attributed it
 at  first to some change of            
circumstances in the roof or in the     
walls of  the room1 but after the       
strictest examination no cause could be 
found  for it4 ,it occurred only once in
 the night2 it was heard almost every   

night1 with few interruptions4 ,it was  
over in an instant1 and it never  took  
place till after the gentleman had gone 
to bed4 ,it was always  distinctly heard
 by his companion1 to whose time of     
going to bed it had  no relation4 ,it   
depended on the gentleman alone1 and it 
followed him  into another apartment    
with another bed1 on the opposite side  
of the  house4 ,accustomed to such      
investigations1 he made the most        
diligent  but fruitless search into its 
cause4 ,the consideration that the sound
  had a special reference to him alone1 
operated upon his imagination1  and he  
did not scruple to acknowledge that the 
recurrence of the  mysterious sound     
produced a superstitious feeling at the 
moment4 ,many  months afterwards it was 
found that the sound arose from the     
partial  opening of the door of a       
wardrobe which was within a few feet of 
the  gentleman's head1 and which had    
been taken into the other apartment4    
,this wardrobe was almost always opened 

before he retired to bed1 and  the door 
being a little too tight1 it gradually  
forced itself open  with a sort of dull 
sound1 resembling the note of a drum4   
,as the door  had only started half an  
inch out of its place1 its change of    
position  never attracted attention4    
,the sound1 indeed1 seemed to come in a 
different direction1 and from a greater 
distance4    ,when sounds so mysterious 
in their origin are heard by persons    
predisposed to a belief in the          
marvellous1 their influence over the    
mind must be very powerful4 ,an inquiry 
into their origin1 if it is made  at    
all1 will be made more in the hope of   
confirming than of removing  the        
original impression1 and the unfortunate
 victim of his own fears  will also be  
the willing dupe of his own judgment4   
,this uncertainty with respect to the   
direction of sound is the  foundation of
 the art of ventriloquism4 ,if we place 
ten men in a row  at such a distance    
from us that they are included in the   

angle within  which we cannot judge of  
the direction of sound1 and if in a calm
 day  each of them speaks in succession1
 we shall not be able with closed  eyes 
to determine from which of the ten men  
any of the sounds proceed1  and we shall
 be incapable of perceiving that there  
is any difference  in the direction of  
the sounds emitted by the two outermost4
 ,if a man  and a child are placed      
within the same angle1 and if the man   
speaks  with the accent of a child      
without any corresponding motion in his 
mouth or face1 we shall necessarily     
believe that the voice comes from  the  
child2 nay1 if the child is so distant  
from the man that the voice  actually   
appears to us to come from the man1 we  
shall still continue  in the belief that
 the child is the speaker2 and this     
conviction would  acquire additional    
strength if the child favoured the      
deception1 by  accommodating its        
features and gestures to the words      
spoken by the  man4 ,so powerful1       

indeed1 is the influence of this        
deception1 that if  a jack-ass1 placed  
near the man1 were to open its mouth1   
and shake  its head responsive to the   
words uttered by his neighbour1 we      
should  rather believe that the ass     
spoke than that the sounds proceeded    
from  a person whose mouth was shut1 and
 the muscles of whose face were in      
perfect repose4 ,if our imagination were
 even directed to a marble  statue or a 
lump of inanimate matter1 as the source 
from which we were  to expect the sounds
 to issue1 we would still be deceived1  
and would  refer the sounds even to     
these lifeless objects4 ,the illusion   
would be  greatly promoted1 if the voice
 were totally different in its tone and 
character from that of the man from whom
 it really comes2 and if he             
occasionally speaks in his own full and 
measured voice1 the belief will  be     
irresistible that the assumed voice     
proceeds from the quadruped or  from the
 inanimate object4    ,when the sounds  

which are required to proceed from any  
given object  are such as they are      
actually calculated to yield1 the       
process of  deception is extremely easy2
 and it may be successfully executed1   
even  if the angle between the real and 
the supposed direction of the sound  is 
much greater than the angle of          
uncertainty4 ,mr4 ,dugald ,stewart  has 
stated some cases in which deceptions of
 this kind were very  perfect4 ,he      
mentions his having seen a person who1  
by counterfeiting  the gesticulations of
 a performer on the violin1 while he    
imitated the  music by his voice1       
riveted the eyes of his audience on the 
instrument1  though every sound they    
heard proceeded from his own mouth4 ,the
 late  ,savile ,carey1 who imitated the 
whistling of the wind through a narrow  
chink1 told ,mr4 ,stewart that he had   
frequently practised this deception  in 
the corner of a coffee-house1 and that  
he seldom failed to see some  of the    
company rise to examine the tightness of

 the windows1 while  others1 more intent
 on their newspapers1 contented         
themselves with  putting on their hats  
and buttoning their coats4 ,mr4 ,stewart
 likewise  mentions an exhibition       
formerly common in some of the          
continental  theatres1 where a performer
 on the stage displayed the dumb-show of
  singing with his lips and eyes and    
gestures1 while another person  unseen  
supplied the music with his voice4 ,the 
deception in this case  he found to be  
at first so complete as to impose upon  
the nicest ear  and the quickest eye2   
but in the progress of the              
entertainment1 he  became distinctly    
sensible of the imposition1 and         
sometimes wondered  that it should have 
misled him for a moment4 ,in this case  
there  can be no doubt that the         
deception was at first the work of the  
imagination1 and was not sustained by   
the acoustic principle4 ,the real  and  
the mock singer were too distant1 and   
when the influence of the  imagination  

subsided1 the true direction of the     
sound was discovered4  ,this detection  
of the imposture1 however1 may have     
arisen from another  cause4 ,if the mock
 singer happened to change the position 
of his head1  while the real singer made
 no corresponding change in his voice1  
the  attentive spectator would at once  
notice this incongruity1 and discover   
the imposition4    ,in many of the feats
 of ventriloquism the performer         
contrives1 under  some pretence or      
other1 to conceal his face1 but         
ventriloquists of  great distinction1   
such as ,m4 ,alexandre1 practise their  
art without any  such concealment4      
,ventriloquism loses its distinctive    
character if its imitations are  not    
performed by a voice from the belly4    
,the voice1 indeed1 does not  actually  
come from that region2 but when the     
ventriloquist utters  sounds from the   
larynx without moving the muscles of his
 face1 he  gives them strength by a     
powerful action of the abdominal        

muscles4  ,hence he speaks by means of  
his belly1 although the throat is the   
real  source from whence the sounds     
proceed4 ,mr4 ,dugald ,stewart has      
doubted  the fact1 that ventriloquists  
possess the power of fetching a voice   
from within3 he cannot conceive what aid
 could be derived from such  an         
extraordinary power2 and he considers   
that the imagination1 when  seconded by 
such powers of imitation as some mimics 
possess1 is quite  sufficient to account
 for all the phenomena of ventriloquism 
which he  has heard4 ,this opinion1     
however1 is strongly opposed by the     
remark  made to ,mr4 ,stewart himself by
 a ventriloquist1 8that his art would   
be perfect1 if it were possible only to 
speak distinctly without any  movement  
of the lips at all40 ,but1 independent  
of this admission1 it is  a matter of   
absolute certainty1 that this internal  
power is exercised  by the true         
ventriloquist4 ,in the account which the
 ,abb ,chapelle  has given of the       

performances of ,m4 ,st4 ,gille and     
,louis ,brabant1 he  distinctly states  
that ,m4 ,st4 ,gille appeared to be     
absolutely mute  while he was exercising
 his art1 and that no change in his     
countenance  could be discovered4#af ,he
 affirms1 also1 that the countenance of 
,louis ,brabant exhibited no change1 and
 that his lips were close and  inactive4
 ,m4 ,richerand1 who attentively watched
 the performances  of ,m4 ,fitz-,james1 
assures us that during his exhibition   
there was  a distention in the          
epigastric region1 and that he could not
 long  continue the exertion without    
fatigue4     #af ,edinburgh ,journal of 
,science1 ,no4 xviii41 p4 #bed4    ,the 
influence over the human mind which the 
ventriloquist derives from  the skilful 
practice of his art is greater than that
 which is exercised  by any other       
species of conjuror4 ,the ordinary      
magician requires his  theatre1 his     
accomplices1 and the instruments of his 
art1 and he enjoys  but a local         

sovereignty within the precincts of his 
own magic circle4  ,the ventriloquist1  
on the contrary1 has the supernatural   
always at  his command4 ,in the open    
fields as well as in the crowded city1  
in  the private apartment as well as in 
the public hall1 he can summon up       
innumerable spirits2 and though the     
persons of his fictitious dialogue  are 
not visible to the eye1 yet they are    
unequivocally present to the            
imagination of his auditors1 as if they 
had been shadowed forth in  the silence 
of a spectral form4 ,in order to convey 
some idea of the  influence of this     
illusion1 ,i shall mention a few        
well-authenticated  cases of successful 
ventriloquism4    ,m4 ,st4 ,gille1 a    
grocer of ,st4 ,germain-en-,laye1 whose 
performances have  been recorded by the 
,abb de la ,chapelle1 had occasion to   
shelter  himself from a storm in a      
neighbouring convent1 where the monks   
were  in deep mourning for a            
much-esteemed member of their community 

who had  been recently buried4 ,while   
lamenting over the tomb of their        
deceased  brother the slight honours    
which had been paid to his memory1 a    
voice  was suddenly heard to issue from 
the roof of the choir bewailing the     
condition of the deceased in purgatory1 
and reproving the brotherhood  for their
 want of zeal4 ,the tidings of this     
supernatural event brought  the whole   
brotherhood to the church4 ,the voice   
from above repeated its  lamentations   
and reproaches1 and the whole convent   
fell upon their  faces1 and vowed to    
make a reparation of their error4 ,they 
accordingly  chanted in full choir a ,de
 ,profundis1 during the intervals of    
which the spirit of the departed monk   
expressed his satisfaction at  their    
pious exercises4 ,the prior afterwards  
inveighed against modern  scepticism on 
the subject of apparitions1 and ,m4 ,st4
 ,gille had great  difficulty in        
convincing the fraternity that the whole
 was a deception4    ,on another        

occasion1 a commission of the ,royal    
,academy of ,sciences  at ,paris1       
attended by several persons of the      
highest rank1 met at ,st4               
,germain-en-,laye to witness the        
performances of ,m4 ,st4 ,gille4 ,the   
real  object of their meeting was       
purposely withheld from a lady of the   
party1 who was informed that an arial   
spirit had lately established  itself in
 the neighbourhood1 and that the object 
of the assembly was  to investigate the 
matter4 ,when the party had sat down to 
dinner in  the open air1 the spirit     
addressed the lady in a voice which     
seemed to  come from above their heads1 
from the surface of the ground at a     
great  distance1 or from a considerable 
depth under her feet4 ,having been thus 
addressed at intervals during two hours1
 the lady was firmly convinced  of the  
existence of the spirit1 and could with 
difficulty be undeceived4    ,another   
ventriloquist1 ,louis ,brabant1 who had 
been valet-de-chambre  to ,francis ,i41 

turned his powers to a more profitable  
account4 ,having  fallen in love with a 
rich and beautiful heiress1 he was      
rejected by  her parents as an          
unsuitable match for their daughter4 ,on
 the death  of her father1 ,louis paid a
 visit to the widow1 and he had no      
sooner  entered the house than she heard
 the voice of her deceased husband      
addressing her from above1 8,give my    
daughter in marriage to ,louis          
,brabant1 who is a man of large fortune 
and excellent character4 ,i  endure the 
inexpressible torments of purgatory for 
having refused her  to him4 ,obey this  
admonition1 and give everlasting repose 
to the soul  of your poor husband40     
,this awful command could not be        
resisted1 and  the widow announced her  
compliance with it4    ,as our conjuror1
 however1 required money for the        
completion of his  marriage1 he resolved
 to work upon the fears of one ,cornu1  
an old  banker at ,lyons1 who had       
amassed immense wealth by usury and     

extortion4  ,having obtained an         
interview with the miser1 he introduced 
the subjects  of demons and spectres1   
and the torments of purgatory2 and1     
during an  interval of silence1 the     
voice of the miser's deceased father was
 heard  complaining of his dreadful     
situation in purgatory1 and calling upon
  his son to rescue him from his        
sufferings by enabling ,louis ,brabant  
to  redeem the ,christians that were    
enslaved by the ,turks4 ,the awe-struck 
miser was also threatened with eternal  
damnation if he did not thus  expiate   
his own sins2 but such was the grasp    
that the banker took of  his gold1 that 
the ventriloquist was obliged to pay him
 another visit4  ,on this occasion1 not 
only his father but all his deceased    
relatives  appealed to him in behalf of 
his own soul and theirs2 and such was   
the loudness of their complaints1 that  
the spirit of the banker was  subdued1  
and he gave the ventriloquist ten       
thousand crowns to liberate  the        

,christian captives4 ,when the miser was
 afterwards undeceived1 he is  said to  
have been so mortified that he died of  
vexation4    ,the ventriloquists of the 
nineteenth century made great additions 
to  their art1 and the performances of  
,m4 ,fitz-,james and ,m4 ,alexandre1    
which must have been seen by many of our
 countrymen1 were far superior  to those
 of their predecessors4 ,besides the art
 of speaking by the  muscles of the     
throat and the abdomen1 without moving  
those of the  face1 these artists had   
not only studied with great diligence   
and  success the modifications which    
sounds of all kinds undergo from        
distance1 obstructions1 and other       
causes1 but had acquired the art  of    
imitating them in the highest           
perfection4 ,the ventriloquist was      
therefore able to carry on a dialogue in
 which the dramatis voces1  as they may 
be called1 were numerous2 and when on   
the outside of an  apartment1 he could  
personate a mob with its infinite       

variety of  noise and vociferation4     
,their influence over an audience was   
still  further extended by a singular   
power over the muscles of the body4 ,m4 
,fitz-,james actually succeeded in      
making the opposite or corresponding    
muscles act differently from each other2
 and while one side of his face  was    
merry and laughing1 the other was full  
of sorrow and in tears4  ,at one moment 
he was tall1 thin1 and melancholic1 and 
after pausing  behind a screen1 he came 
out 8bloated with obesity and staggering
 with  fulness40 ,m4 ,alexandre         
possessed the same power over his face  
and  figure2 and so striking was the    
contrast of two of these forms1 that an 
excellent sculptor1 ,mr4 ,joseph1 has   
perpetuated them in marble4    ,this new
 acquirement of the ventriloquist       
enabled him1 in his own  single person  
and with his own single voice1 to       
represent upon the  stage a dramatic    
composition which would have required   
the assistance  of several actors4      

,although only one character in the     
piece could be  seen at the same time1  
yet they all appeared during its        
performance1  and the change of face and
 figure on the part of the ventriloquist
 was  so perfect1 that his personal     
identity could not be recognized in the 
dramatis person4 ,this deception was    
rendered still more complete by  a      
particular construction of the dresses1 
which enabled the performer  to reappear
 in a new character after an interval so
 short that the  audience necessarily   
believed that it was another person4    
,it is a curious circumstance that      
,captain ,lyon found among the          
,esquimaux of ,igloolik ventriloquists  
of no mean skill4 ,there is much        
rivalry among the professors of the art1
 who do not expose each  other's        
secrets1 and their exhibitions derive   
great importance from  the rarity of    
their occurrence4 ,the following account
 of one of them  is so interesting that 
we shall give the whole of it in        

,captain ,lyon's  words3--    8,amongst 
our ,igloolik acquaintances were two    
females and a few male  wizards1 of whom
 the principal was ,toolemak4 ,this     
personage was cunning  and intelligent2 
and1 whether professionally1 or from his
 skill in  the chase1 but perhaps from  
both reasons1 was considered by all the 
tribe as a man of importance4 ,as ,i    
invariably paid great deference  to his 
opinion on all subjects connected with  
his calling1 he freely  communicated to 
me his superior knowledge1 and did not  
scruple to  allow of my being present at
 his interviews with ,tornga1 or his    
patron spirit4 ,in consequence of this1 
,i took an early opportunity  of        
requesting my friend to exhibit his     
skill in my cabin4 ,his old  wife was   
with him1 and by much flattery and an   
accidental display  of a glittering     
knife and some beads1 she assisted me in
 obtaining  my request4 ,all light      
excluded1 our sorcerer began chanting to
 his  wife with great vehemence1 and she

 in return answered by singing  the     
,amna-aya1 which was not discontinued   
during the whole ceremony4  ,as far as  
,i could hear1 he afterwards began      
turning himself rapidly  round1 and in a
 loud1 powerful voice vociferated for   
,tornga with great  impatience1 at the  
same time blowing and snorting like a   
walrus4 ,his  noise1 impatience1 and    
agitation increased every moment1 and he
 at  length seated himself on the deck1 
varying his tones1 and making a         
rustling with his clothes4 ,suddenly the
 voice seemed smothered1 and was  so    
managed as to sound as if retreating    
beneath the deck1 each moment  becoming 
more distant1 and ultimately giving the 
idea of being many  feet below the      
cabin1 when it ceased entirely4 ,his    
wife now1 in answer  to my queries1     
informed me very seriously1 that he had 
dived1 and that  he would send up       
,tornga4 ,accordingly1 in about half a  
minute1 a distant  blowing was heard    
very slowly approaching1 and a voice1   

which differed  from that at first      
heard1 was at times mingled with the    
blowing1 until  at length both sounds   
became distinct1 and the old woman      
informed  me that ,tornga was come to   
answer my questions4 ,i accordingly     
asked  several questions of the         
sagacious spirit1 to each of which      
inquiries ,i  received an answer by two 
loud claps on the deck1 which ,i was    
given to  understand were favourable4   
8,a very hollow1 yet powerful voice1    
certainly much different from the  tones
 of ,toolemak1 now chanted for some     
time1 and a strange jumble of  hisses1  
groans1 shouts1 and gabblings like a    
turkey1 succeeded in rapid  order4 ,the 
old woman sang with increased energy2   
and as ,i took it for  granted that this
 was all intended to astonish the       
,kabloona1 ,i cried  repeatedly that ,i 
was very much afraid4 ,this1 as ,i      
expected1 added fuel  to the fire1 until
 the poor immortal1 exhausted by its own
 might1 asked  leave to retire4    8,the

 voice gradually sank from our hearing  
as at first1 and a very  indistinct     
hissing succeeded2 in its advance it    
sounded like the tone  produced by the  
wind on the brass chord of an olian     
harp4 ,this was  soon changed to a rapid
 hiss like that of a rocket1 and        
,toolemak with  a yell announced his    
return4 ,i had held my breath at the    
first distant  hissing1 and twice       
exhausted myself1 yet our conjuror did  
not once  respire1 and even his         
returning and powerful yell was uttered 
without a  previous stop or inspiration 
of air4    8,light being admitted1 our  
wizard1 as might be expected1 was in a  
profuse perspiration1 and certainly much
 exhausted by his exertions1  which had 
continued for at least half an hour4 ,we
 now observed a couple  of bunches1 each
 consisting of two stripes of white     
deer-skin1 and a  long piece of sinew1  
attached to the back of his coat4 ,these
 we had not  seen before1 and were      
informed that they had been sewn on by  

,tornga  while he was below40#ag     #ag
 ,private ,journal of ,captain ,g4 ,f4  
,lyon4 ,london1 #ahbd1 pp4 #ceh1   #cfa4
    ,captain ,lyon had the good fortune 
to witness another of ,toolemak's       
exhibitions1 and he was much struck with
 the wonderful steadiness of  the wizard
 throughout the whole performance1 which
 lasted an hour and  a half4 ,he did not
 once appear to move1 for he was so     
close to the  skin behind which ,captain
 ,lyon sat1 that if he had done so he   
must  have perceived it4 ,captain ,lyon 
did not hear the least rustling of his  
clothes1 or even distinguish his        
breathing1 although his outcries were   
made with great exertion4#ah     #ah    
,id4 p4 #cff4          ,,letter ,,viii4 
,musical and harmonic sounds            
explained--,power of breaking glasses   
with the voice--,musical sounds from the
 vibration of a column   of air--and of 
solid bodies--,kaleidophone--,singular  
acoustic   figures produced on sand laid
 on vibrating plates of glass--and   on 

stretched membranes--,vibration of flat 
rulers and cylinders   of               
glass--,production of silence from two  
sounds--,production   of darkness from  
two lights--,explanation of these       
singular   effects--,acoustic           
automaton--,droz's bleating             
sheep--,maillardet's                    
singing-bird--,vaucanson's              
flute-player--,his pipe and             
tabor-player--,baron ,kempelen's        
talking-engine--,kratzenstein's         
speaking-machine--,mr4 ,willis's        
researches4      ,among the discoveries 
of modern science1 there are few more   
remarkable  than those which relate to  
the production of harmonic sounds4 ,we  
are all familiar with the effects of    
musical instruments1 from the           
deep-toned voice of the organ to the    
wiry shrill of the ,jew's harp4  ,we sit
 entranced under their magical          
influence1 whether the ear is  charmed  
with the melody of their sounds1 or the 
heart agitated by the  sympathies which 

they rouse4 ,but though we may admire   
their external  form1 and the skill of  
the artist who constructed them1 we     
never think  of inquiring into the cause
 of such extraordinary combinations4    
,sounds of all kinds are conveyed to the
 organ of hearing through the  air2 and 
if this element were to be destroyed1   
all nature would be  buried in the      
deepest silence4 ,noises of every       
variety1 whether they  are musical or   
discordant1 high or low1 move through   
the air of our  atmosphere at the       
surface of the earth with a velocity of 
#ajij feet  in a second1 or #gfe miles  
per hour2 but in sulphurous acid gas    
sound  moves only through #gea feet in a
 second1 while in hydrogen gas it moves 
with the great velocity of #cjjj feet4  
,along fluid and solid bodies1  its     
progress is still more rapid4 ,through  
water it moves at the rate  of #dgjh    
feet in a second1 through tin at the    
rate of #hage feet1 and  through iron1  
glass1 and some kinds of wood1 at the   

rate of #ah1ecj feet4    ,when a number 
of single and separate sounds follow    
each other in rapid  succession1 they   
produce a continued sound1 in the same  
manner as a  continuous circle of light 
is produced by whirling round a burning 
stick before the eye4 ,in order that the
 sound may appear a single one  to the  
ear1 nearly sixteen separate sounds must
 follow one another  every second4 ,when
 these sounds are exactly similar1 and  
recur at equal  intervals1 they form a  
musical sound4 ,in order to produce such
 sounds  from the air1 it must receive  
at least sixteen equally distant        
impulses  or strokes in a second4 ,the  
most common way of producing this effect
 is  by a string or wire ,a ,b1 ,fig4   
#dj1 stretched between the fixed points 
,a1  ,b4 ,if this string is taken by the
 middle and pulled aside1 or if it is   
suddenly struck1 it will vibrate between
 its two fixed points1 as shown  in the 
figure1 passing alternately on each side
 of its axis ,a ,b1 the  vibrations     

gradually diminishing by the resistance 
of the air till the  string is brought  
to rest4 ,its vibrations1 however1 may  
be kept up1 by  drawing a rosined       
fiddle-bow across it1 and while it is   
vibrating it  will give out a sound     
corresponding to the rapidity of its    
vibrations1  and arising from the       
successive blows or impulses given to   
the air by  the string4 ,this sound is  
called the fundamental sound of the     
string1  and its acuteness or sharpness 
increases with the number of vibrations 
which the string performs in a second4  
,illustration3 ,fig4 #dj4    ,if we now 
touch the vibrating string ,a ,b lightly
 with the finger1  or with a feather at 
the middle point ,c1 ,fig4 #dj1 it will 
give out a  more acute but fainter sound
 than before1 and while the extent of   
its  vibrations is diminished1 their    
frequency is doubled4 ,in like manner1  
if we touch the string ,a ,b1 ,fig4 #dj1
 at a point ,c1 so that ,a ,c is        
one-third of ,a ,b1 the note will be    

still more acute1 and correspond  to    
thrice the number of vibrations4 ,all   
this might have been expected2  but the 
wonderful part of the experiment is1    
that the vibrating string  ,a ,b divides
 itself at ,c into two parts ,a ,c1 ,c  
,b1 the part ,a ,c  vibrating round ,a  
and ,c as fixed points1 and the part ,c 
,b round ,c and  ,b1 but always so that 
the part ,a ,c is at the same distance  
on the  one side of the axis ,a ,b as at
 ,a m ,c1 while the part ,c ,b is on    
the other side1 as at ,c n ,b4 ,hence   
the point ,c1 being always pulled  by   
equal and opposite forces1 remains at   
rest as if it were absolutely  fixed4   
,this stationary point is called a node1
 and the vibrating  portions ,am ,c1 ,c 
n ,b loops4 ,the very same is true of   
the string  ,a ,b1 the points ,c and ,d 
being stationary points2 and upon the   
same principle a string may be divided  
into any number of vibrating  portions4 
,in order to prove that the string is   
actually vibrating in  these equal      

subdivisions1 we have only to place a   
piece of light paper  with a notch in it
 on different parts of the string4 ,at  
the nodes ,c and  ,d it will remain     
perfectly at rest1 while at m or n in   
the middle  of the loops it will be     
thrown off or violently agitated4       
,the acute sounds given out by each of  
the vibrating portions are called       
harmonic sounds1 and they accompany the 
fundamental sound of the  string in the 
very same manner as we have already seen
 that the eye  sees the accidental or   
harmonic colours while it is affected   
with the  fundamental colour4    ,the   
subdivision of the string1 and          
consequently the production of  harmonic
 sounds1 may be effected without        
touching the string at all1  and by     
means of a sympathetic action conveyed  
by the air4 ,if a string  ,a ,b1 for    
example1 ,fig4 #dj1 is at rest1 and if a
 shorter string ,a ,c1  one third of its
 length1 fixed at the two points ,a and 
,c1 is set  vibrating in the same room1 

the string ,a ,b will be set vibrating  
in  three loops like ,a ,b1 giving out  
the same harmonic sounds as the  small  
string ,a ,c4    ,it is owing to this   
property of sounding bodies that singers
 with great  power of voice are able to 
break into pieces a large tumbler glass1
 by  singing close to it its proper     
fundamental note2 and it is from the    
same sympathetic communication of       
vibrations that two pendulum clocks     
fixed to the same wall1 or two watches  
lying upon the same table1 will  take   
the same rate of going1 though they     
would not agree with one  another if    
placed in separate apartments4 ,mr4     
,ellicott even observed  that the       
pendulum of the one clock will stop that
 of the other1 and  that the stopped    
pendulum will1 after a certain time1    
resume its  vibrations1 and in its turn 
stop the vibrations of the other        
pendulum4    ,the production of musical 
sounds by the vibrations of a column of 
air  in a pipe is familiar to every     

person1 but the extraordinary mechanism 
by which it is effected is known        
principally to philosophers4 ,a column  
of air in a pipe may be set vibrating by
 blowing over the open end of  it1 as is
 done in ,pan's pipes2 or by blowing    
over a hole in its side1  as in the     
flute2 or by blowing through an aperture
 called a reed1  with a flexible tongue1
 as in the clarionet4 ,in order to      
understand  the nature of this          
vibration1 let ,,ab1 ,fig4 #da1 be a    
pipe or tube1 and  let us place in it a 
spiral spring ,,ab1 in which the coil or
 spire are  at equal distances1 each end
 of the spiral being fixed to the end of
  the tube4 ,this elastic spring may be 
supposed to represent the air in  the   
pipe1 which is of equal density         
throughout4 ,if we take hold of  the    
spring at m1 and push the point m       
towards ,a and towards ,b in            
succession1 it will give us a good idea 
of the vibration of an elastic  column  
of air4 ,when m is pushed towards ,a1   

the spiral spring will  be compressed or
 condensed1 as shown at m ,a1 ,no4 #b1  
while at the  other end it will be      
dilated or rarefied1 as shown at m ,b1  
and in  the middle of the tube it will  
have the same degree of compression as  
in ,no4 #a4 ,when the string is drawn to
 the other end of the tube ,b1 the      
spring will be1 as in ,no4 #c1 condensed
 at the end ,b1 and dilated at  the end 
,a4 ,now when a column of air vibrates  
in a pipe ,,ab1 the whole  of it rushes 
alternately from ,b to ,a1 as in ,no4   
#b1 and from ,a to ,b as  in ,no4 #c1   
being condensed at the end ,a1 ,no4 #b1 
and dilated or rarefied  at the end ,b1 
while in ,no4 #c it is rarefied at ,a   
and condensed at ,b1  preserving its    
natural density at the middle point     
between ,a and ,b4 ,in  the case of the 
spring the ends ,,ab are alternately    
pushed outwards and  pulled inwards by  
the spring1 the end ,a being pushed     
outwards in ,no4 #b1  and ,b pulled     
inwards1 while in ,no4 #c ,a is pulled  

inwards and ,b pushed  outwards4        
,illustration3 ,fig4 #da4    ,that the  
air vibrating in a pipe is actually in  
the state now  described1 may be shown  
by boring small holes in the pipe1 and  
putting  over them pieces of a fine     
membrane4 ,the membrane opposite to the 
middle part between ,a and ,b where the 
particles of the air have the  greatest 
motion1 will be violently agitated1     
while at points nearer the  ends ,a and 
,b it will be less and less affected4   
,illustration3 ,fig4 #db4    ,let us now
 suppose two pipes1 ,,ab1 ,,bc1 to be   
joined together as in ,fig4  #db1 and to
 be separated by a fixed partition at   
,b2 and let a spiral  spring be fixed in
 each4 ,let the spring ,,ab be now      
pushed to the end  ,a1 while the spring 
,,bc is pushed to ,c1 as in ,no4 #a1 and
 back again1  as in ,no4 #b1 but always 
in opposite directions2 then it is      
obvious  that the partition ,b is in    
,no4 #a drawn in opposite directions    
towards  ,a and towards ,c1 and always  

with forces equal to each other3 that   
is1  when ,b is drawn slightly towards  
,a1 which it is at the beginning of  the
 motion1 it is also drawn slightly      
towards ,c2 and when it is drawn        
forcibly towards ,a1 as it is at the end
 of the motion of the spring1  it is    
also drawn forcibly towards ,c4 ,if the 
partition ,b1 therefore1 is  moveable1  
it will still remain fixed during the   
opposite excursions  of the spiral      
springs2 nay1 if we remove the          
partition1 and hook the  end of one     
spiral spring to the end of the other1  
the node or point of  junction will     
remain stationary during the movements  
of the springs1  because at every       
instant that point is drawn by equal and
 opposite  forces4 ,if three1 four1 or  
five spiral springs are joined in a     
similar manner1 we may conceive them all
 vibrating between their nodes  in the  
same manner4    ,upon the very same     
principles we may conceive a long column
 of air  without partitions dividing    

itself into two1 three1 or four smaller 
columns1 each of which will vibrate     
between its nodes in the same  manner as
 the spiral spring4 ,at the middle point
 of each small  vibrating column1 the   
air will be of its natural density1 like
 that  of the atmosphere2 while at the  
nodes ,b1 c4 it will be in a state of   
condensation and rarefaction            
alternately4    ,if1 when the air is    
vibrating in one column in the pipe     
,,ab1 as in ,fig4  #da1 ,no4 #b1 #c1 we 
conceive a hole made in the middle1 the 
atmospheric  air will not rush in to    
disturb the vibration1 because the air  
within  the pipe and without it has     
exactly the same density4 ,nay1 if1     
instead  of a single hole1 we were to   
cut a ring out of the pipe at the middle
  point1 the column would vibrate as    
before4 ,but if we bore a hole  between 
the middle and one of the ends1 where   
the vibrating column  must be either in 
a state of condensation or rarefaction1 
the air must  either rush out or rush   

in1 in order to establish the           
equilibrium4  ,the air opposite the hole
 will then be brought to the state of   
the  external air1 like that in the     
middle of the pipe2 it will become the  
middle of a vibrating column3 and the   
whole column of air1 instead of         
vibrating as one1 will vibrate as two   
columns1 each column vibrating  with    
twice the velocity1 and yielding        
harmonic sounds along with the          
fundamental sound of the whole columns1 
in the same manner as we have  already  
explained with regard to vibrating      
strings4 ,by opening other  holes we may
 subdivide a vibrating column into any  
number of smaller  vibrating columns4   
,the holes in flutes1 clarionets1 c4 are
 made for  this purpose4 ,when they are 
all closed up1 the air vibrates in one  
column2 and by opening and shutting the 
different holes in succession1  the     
number of vibrating columns is increased
 or diminished at pleasure1  and        
consequently the harmonic sounds will   

vary in a similar manner4    ,curious as
 these phenomena are1 they are still    
surpassed by those  which are exhibited 
during the vibration of solid bodies4 ,a
 rod or  bar of metal or glass may be   
made to vibrate either longitudinally or
  laterally4    ,an iron rod will       
vibrate longitudinally1 like a column of
 air1 if we  strike it at one end in the
 direction of its length2 or rub it in  
the same direction with a wetted finger1
 and it will admit the same  fundamental
 note as a column of air ten or eleven  
times as long1  because sound moves so  
much faster in iron than in air4 ,when  
the  iron rod is thus vibrating along   
its length1 the very same changes  which
 we have shown in ,fig4 #da1 as produced
 in a spiral spring1 or  in a column of 
air1 take place in the solid metal4 ,all
 its particles  move alternately towards
 ,a and towards ,b1 the metal being in  
the one  case condensed at the end to   
which the particles move1 and expanded  
at the end from which they move1 and    

retaining its natural density  in the   
middle of the rod4 ,if we now hold this 
rod in the middle1 by  the finger and   
thumb lightly applied1 and rub it in the
 middle either  of ,,ab or ,,bc with a  
piece of cloth sprinkled with powdered  
rosin1  or with a well-rosined          
fiddle-bow drawn across the rod1 it will
  divide itself into two vibrating      
portions ,,ab1 ,,bc1 each of which will 
vibrate1 as shown in ,fig4 #db1 like the
 two adjacent columns of air1  the      
section of the rod1 or the particles    
which compose that section  at ,b1 being
 at perfect rest4 ,by holding the rod at
 any intermediate  point between ,a and 
,b1 so that the distance from ,a to the 
finger and  thumb is one-third1         
one-fourth1 one-fifth1 c4 of the whole  
length ,,ac1  and rubbing one of the    
divisions in the middle1 the rod will   
divide  itself into #c1 #d1 #e1 c4      
vibrating portions1 and give out        
corresponding  harmonic sounds4         
,illustration3 ,fig4 #dc4    ,a rod of  

iron may be made to vibrate laterally or
 transversely1 by  fixing one end of it 
firmly1 as in a vice1 and leaving the   
other free1  or by having both ends free
 or both fixed4 ,when a rod1 fixed at   
one  end and free at the other1 is made 
to vibrate1 its mode of vibrating  may  
be rendered evident to the eye2 and for 
the purpose of doing  this1 ,mr4        
,wheatstone has contrived a curious     
instrument1 called the  ,kaleidophone1  
which is shown in ,fig4 #dc4 ,it        
consists of a circular  base of wood    
,,ab1 about nine inches in diameter and 
one inch thick1  and having four brass  
sockets firmly fixed into it at ,c1 ,d1 
,e1 and ,f4  ,into these sockets are    
screwed four vertical steel rods ,c1 ,d1
 ,e1 and  ,f1 about thirteen or fourteen
 inches long2 one being a square rod1   
another a bent cylindrical one1 and the 
other two cylindrical ones of  different
 diameters4 ,on the extremities of these
 rods are fixed small  quicksilvered    
glass beads1 either singly or in groups1

 so that when  the instrument is placed 
in the light of the sun or in that of a 
lamp1  bright images of the sun or flame
 are seen reflected on each bead4 ,if   
any of these rods is set vibrating1     
these luminous images will form         
continuous and returning curve lines in 
a state of constant variation1  each    
different rod giving curves of different
 characters1 as shown in  ,fig4 #dd4    
,illustration3 ,fig4 #dd4    ,the       
,melodion1 an instrument of great power1
 embracing five octaves1  operates by   
means of the vibrations of metallic rods
 of unequal  lengths1 fixed at one end  
and free at the other4#ai ,a narrow and 
thin  plate of copper is screwed to the 
free extremity of each rod1 and at      
right angles to its length2 and its     
surface is covered with a small  piece  
of felt1 impregnated with rosin4 ,this  
narrow band is placed near  the         
circumference of a revolving cylinder1  
and1 by touching the key1  it is made to
 descend till it touches the revolving  

cylinder1 and  gives out its sound4 ,the
 sweetness and power of this instrument 
are  unrivalled2 and such is the        
character of its tones1 that persons of 
a  nervous temperament are often        
entirely overpowered by its effects4    
#ai ,see ,edinburgh ,encyclopdia1 ,art4 
,,science1 ,curiosities in1 ,vol4       
xvii41 p4 #efc4    ,the vibrations of   
plates of metal or glass of various     
forms exhibit  a series of the most     
extraordinary phenomena1 which are      
capable of  being shown by very simple  
means4 ,these phenomena are displayed in
 an  infinite variety of regular figures
 assumed by sand or fine lycopodium     
powder1 strewed over the surface of the 
glass plate4 ,in order to  produce these
 figures1 we must pinch or damp the     
plate at one or more  places1 and when  
the sand is strewed upon its surface1 it
 is thrown  into vibrations by drawing a
 fiddle-bow over different parts of its 
circumference4 ,the method of damping or
 pinching plates is shown in  ,fig4 #de4

 ,in ,no4 #a1 a square plate of glass   
,,ab1 ground smooth at its  edges1 is   
pinched by the finger and thumb4 ,in    
,no4 #b1 a circular plate  is held by   
the thumb against the top c of a        
perpendicular rod1 and  damped by the   
fingers at two different points of its  
circumference4  ,in ,no4 #c it is damped
 at three points of its circumference2 c
 and  d by the thumb and finger1 and at 
e by pressing it against a fixed        
obstacle a b4 ,by means of a clamp like 
that at ,no4 #d1 it may be  damped at a 
greater number of points4               
,illustration3 ,fig4 #de4    ,no #a     
,no #b    ,no #c    ,no #d              
,illustration3 ,fig4 #df4    ,no #a     
,no #b    ,no #c    ,no #d      ,if we  
take a square plate of glass1 such as   
that shown in ,fig4 #df1  ,no4 #a1 and1 
pinching it at its centre1 draw the     
fiddle-bow near one of  its angles1 the 
sand will accumulate in the form of a   
cross1 as shown  in the figure1 being   
thrown off the parts of the plate that  

are in a  state of vibration1 and       
settling in the nodes or parts which are
 at  rest4 ,if the bow is drawn across  
the middle of one of the edges1 the     
sand will accumulate as in ,no4 #b4 ,if 
the plate is pinched at ,n1 ,no4 #c1    
and the bow applied at ,f and           
perpendicular to ,,ab1 the sand will    
arrange  itself in three parallel lines1
 perpendicular to a fourth passing      
through ,f and ,n4 ,but if the point ,n1
 where it is pinched1 is a little       
farther from the edge than in ,no4 #c1  
the parallel lines will change  into    
curves as in ,no4 #d4    ,if the plate  
of glass is circular1 and pinched at its
 centre1 and also  at a point of its    
circumference1 and if the bow is applied
 at a point  #de from the last point1   
the figure of the sand will be as in    
,fig4 #dg1  ,no4 #a4 ,if with the same  
plate1 similarly pinched1 the bow is    
drawn over  a part #cj from the pinched 
point of the circumference1 the sand    
will  form six radii as in ,no4 #b4     

,when the centre of the plate is left   
free1  a different set of figures is    
produced1 as shown in ,no4 #c and ,no4  
#d4  ,when the plate is pinched near its
 edge1 and the bow applied #de from  the
 point pinched1 a circle of sand will   
pass through that point1 and  two       
diameters of sand1 at right angles to   
each other1 will be formed as  in ,no4  
#c4 ,when a point of the circumference  
is pressed against a fixed  obstacle1   
and the bow applied #cj from that point1
 the figure in ,no4 #d  is produced4    
,illustration3 ,fig4 #dg4      ,no4 #a4 
,no4 #b4    ,no4 #c4   ,no4 #d4    ,if1 
in place of a solid plate1 we strew the 
sand over a stretched  membrane1 the    
sand will form itself into figures1 even
 when the  vibrations are communicated  
to the membrane through the air4 ,in    
order  to make these experiments1 we    
must stretch a thin sheet of wet paper1 
such as vegetable paper1 over the mouth 
of a tumbler-glass with a  footstalk1   
and fix it to the edges with glue4 ,when

 the paper is dry1 a  thin layer of dry 
sand is strewed upon its surface4 ,if we
 place this  membrane upon a table1 and 
hold immediately above it1 and parallel 
to the membrane1 a plate of glass       
vibrating so as to give any of the      
figures shown in ,fig4 #dg1 the sand    
upon the membrane will imitate  exactly 
the figure upon the glass4 ,if the glass
 plate1 in place of  vibrating          
horizontally1 is made to vibrate in an  
inclined position1 the  figures on the  
membrane will change with the           
inclination1 and the sand  will assume  
the most curious arrangements4 ,the     
figures thus produced  vary with the    
size of the membrane1 with its material1
 its tension1 and  its shape4 ,when the 
same figure occurs several times in     
succession1 a  breath upon the paper    
will change its degree of tension1 and  
produce  an entirely new figure1 which1 
as the temporary moisture evaporates1   
will return to the original figure1     
through a number of intermediate  ones4 

,the pipe of an organ at the distance of
 a few feet1 or the notes  of a flute at
 the distance of half a foot1 will      
arrange the sand on the  membrane into  
figures which perpetually change with   
the sound that is  produced4    ,the    
manner in which flat rulers and         
cylinders of glass perform their        
vibrations is very remarkable4 ,if a    
glass plate about twenty-seven  inches  
long1 six-tenths of an inch broad1 and  
six hundredths of an  inch thick1 is    
held by the edges between the finger and
 thumb1 and has  its lower surface1 near
 either end1 rubbed with a piece of wet 
cloth1  sand laid upon its upper surface
 will arrange itself in parallel lines  
at right angles to the length of the    
plate4 ,if the place of these lines  is 
marked with a dot of ink1 and the other 
side of the glass ruler is  turned      
upwards1 and the ruler made to vibrate  
as before1 the sand will  now accumulate
 in lines intermediate between the      
former lines1 so that  the motions of   

one-half the thickness of the glass     
ruler are precisely  the reverse of     
those of the corresponding parts of the 
other half4    ,as these singular       
phenomena have not yet been made        
available by the  scientific conjuror1  
we must be satisfied with this brief    
notice of  them2 but there is still one 
property of sound1 which has its analogy
  also in light1 too remarkable to be   
passed without notice4 ,this  property  
has more of the marvellous in it than   
any result within the  wide range of the
 sciences4 ,two loud sounds may be made 
to produce  silence1 and two strong     
lights may be made to produce darkness6 
,if two equal and similar strings1 or   
the columns of air in two equal  and    
similar pipes1 perform exactly #ajj     
vibrations in a second1  they will      
produce each equal waves of sound1 and  
these waves will  conspire in generating
 an uninterrupted sound1 double of      
either of  the sounds1 heard separately4
 ,if the two strings or the two columns 

of air are not in unison1 but nearly so1
 as in the case where the  one vibrates 
#ajj and the other #aja times in a      
second1 then at the  first vibration the
 two sounds will form one of double the 
strength  of either2 but the one will   
gradually gain upon the other1 till at  
the fiftieth vibration it has gained    
half a vibration on the other4  ,at this
 instant the two sounds will destroy one
 another1 and an  interval of perfect   
silence will take place4 ,the sound will
 instantly  commence1 and gradually     
increase till it becomes loudest at the 
hundredth vibration1 where the two      
vibrations conspire in producing  a     
sound double of either4 ,an interval of 
silence will again occur at  the #aejth1
 #bejth1 #cejth vibration1 or every     
second1 while a sound of  double the    
strength of either will be heard at the 
#bjjth1 #cjjth1 and  #djjth vibration4  
,when the unison is very defective1 or  
when there is  a great difference       
between the number of vibrations which  

the two  strings or columns of air      
perform in a second1 the successive     
sounds  and intervals of silence        
resemble a rattle4 ,with a powerful     
organ1 the  effect of this experiment is
 very fine1 the repetition of the sounds
  wow--wow--wow--representing the double
 sound and the interval  of silence     
which arise from the total extinction of
 the two separate  sounds4    ,the      
phenomenon corresponding to this in the 
case of light is perhaps  still more    
surprising4 ,if a beam of red light     
issues from a luminous  point1 and falls
 upon the retina1 we shall see          
distinctly the luminous  object from    
which it proceeds2 but if another pencil
 of red light  issues from another      
luminous point1 anyhow situated1        
provided the  difference between its    
distance and that of the other luminous 
point  from the point of the retina1 on 
which the first beam fell1 is the       
#behth thousandth part of an inch1 or   
exactly twice1 thrice1 four  times1 c41 

that distance2 and if this second beam  
falls upon the  same point of the       
retina1 the one light will increase the 
intensity  of the other1 and the eye    
will see twice as much light as when it 
received only one of the beams          
separately4 ,all this is nothing more   
than what might be expected from our    
ordinary experience4 ,but if  the       
difference in the distances of the two  
luminous points is only  one-half of the
 #behth thousandth part of an inch1 or  
#a1 #b1 #c1  #d1 times that distance1   
the one light will extinguish the other 
and  produce absolute darkness4 ,if the 
two luminous points are so situated1    
that the difference of their distances  
from the point of the retina is         
intermediate between #a and #a1 or #b   
and #b1 above the #behth thousandth     
part of an inch1 the intensity of the   
effect which they produce will  vary    
from absolute darkness to double the    
intensity of either light4 ,at  #a1 #b1 
#c times1 c41 the #behth thousandth of  

an inch1 the intensity  of the two      
combined lights will be equal only to   
one of them acting  singly4 ,if the     
lights1 in place of falling upon the    
retina1 fall upon  a sheet of white     
paper1 the very same effect will be     
produced1 a black  spot being produced  
in the one case1 and a bright white one 
in the  other1 and intermediate degrees 
of brightness in intermediate cases4 ,if
  the two lights are violet1 the        
difference of distances at which the    
preceding phenomena will be produced    
will be the #aegth thousandth part  of  
an inch1 and it will be intermediate    
between the #behth and the #aegth       
thousandth part of an inch for the      
intermediate colours4 ,this curious     
phenomenon may be easily shown to the   
eye1 by admitting the sun's light  into 
a dark room through a small hole about  
the #djth or #ejth part of  an inch in  
diameter1 and receiving the light on a  
sheet of paper4 ,if  we hold a needle or
 piece of slender wire in this light1   

and examine  its shadow1 we shall find  
that the shadow consists of bright and  
dark  stripes succeeding each other     
alternately1 the stripe in the very     
middle or axis of the shadow being a    
bright one4 ,the rays of light  which   
are bent into the shadow1 and which meet
 in the very middle of  the shadow1 have
 exactly the same length of path1 so    
that they form a  bright fringe of      
double the intensity of either2 but the 
rays which  fall upon a point of the    
shadow at a certain distance from the   
middle1  have a difference in the length
 of their paths1 corresponding to the   
difference at which the lights destroy  
each other1 so that a black  stripe is  
produced on each side of the middle     
bright one4 ,at a greater  distance from
 the middle1 the difference becomes such
 as to produce a  bright stripe1 and so 
on1 a bright and a dark stripe          
succeeding each  other to the margin of 
the shadow4    ,the explanation which   
philosophers have given of these strange

  phenomena is very satisfactory1 and   
may be easily understood4 ,when a  wave 
is made on the surface of a still pool  
of water1 by plunging a  stone into it1 
the wave advances along the surface1    
while the water  itself is never carried
 forward1 but merely rises into a height
 and  falls into a hollow1 each portion 
of the surface experiencing an          
elevation and a depression in its turn4 
,if we suppose two waves equal  and     
similar to be produced by two separate  
stones1 and if they reach  the same spot
 at the same time1 that is1 if the two  
elevations should  exactly coincide1    
they would unite their effects1 and     
produce a  wave twice the size of       
either2 but if the one wave should be   
just so  far before the other1 that the 
hollow of the one coincided with the    
elevation of the other1 and the         
elevation of the one with the hollow  of
 the other1 the two waves would         
obliterate or destroy one another1  the 
elevation as it were of the one filling 

up half the hollow of the  other1 and   
the hollow of the one taking away half  
the elevation of the  other1 so as to   
reduce the surface to a level4 ,these   
effects will be  actually exhibited by  
throwing two equal stones into a pool of
 water1  and it will be seen that there 
are certain lines of a hyperbolic form  
where the water is quite smooth1 in     
consequence of the equal waves          
obliterating one another1 while1 in     
other adjacent parts1 the water is      
raised to a height corresponding to both
 the waves united4    ,in the tides of  
the ocean we have a fine example of the 
same principle4  ,the two immense waves 
arising from the action of the sun and  
moon upon  the ocean produce our        
spring-tides by their combination1 or   
when the  elevations of each coincide2  
and our neap-tides1 when the elevation  
of  the one wave coincides with the     
depression of the other4 ,if the sun and
  moon had exerted exactly the same     
force upon the ocean1 or produced  tide 

waves of the same size1 then our        
neap-tides would have disappeared       
altogether1 and the spring-tide would   
have been a wave double of the  wave    
produced by the sun and moon separately4
 ,an example of the effect  of the      
equality of the two waves occurs in the 
port of ,batsha1 where  the two waves   
arrive by channels of different lengths1
 and actually  obliterate each other4   
,now1 as sound is produced by           
undulations or waves in the air1 and  as
 light is supposed to be produced by    
waves or undulations in an  ethereal    
medium1 filling all nature1 and         
occupying the pores of  transparent     
bodies1 the successive production of    
sound and silence by  two loud sounds1  
or of light and darkness by two bright  
lights1 may be  explained in the very   
same manner as we have explained the    
increase  and the obliteration of waves 
formed on the surface of water4 ,if this
  theory of light be correct1 then the  
breadth of a wave of red light  will be 

the #behth thousandth part of an inch1  
the breadth of a wave of  green light   
the #bjgth thousandth part of an inch1  
and the breadth of a  wave of violet    
light the #aegth thousandth part of an  
inch4    ,among the wonders of modern   
skill1 we must enumerate those beautiful
  automata by which the motions and     
actions of man and other animals have   
been successfully imitated4 ,i shall    
therefore describe at present some  of  
the most remarkable acoustic automata1  
in which the production of  musical and 
vocal sounds has been the principal     
object of the artist4    ,many very     
ingenious pieces of acoustic mechanism  
have been from time to  time exhibited  
in ,europe4 ,the celebrated ,swiss      
mechanist1 ,m4 le ,droz1  constructed   
for the ,king of ,spain the figure of a 
sheep1 which imitated  in the most      
perfect manner the bleating of that     
animal2 and likewise  the figure of a   
dog watching a basket of fruit1 which1  
when any of the  fruit was taken away1  

never ceased barking till it was        
replaced4    ,the singing-bird of ,m4   
,maillardet1 which he exhibited in      
,edinburgh  many years ago1 is still    
more wonderful4#bj ,an oval box1 about  
three  inches long1 was set upon the    
table1 and in an instant the lid flew   
up1  and a bird of the size of the      
humming-bird1 and of the most beautiful 
plumage1 started from its nest4 ,after  
fluttering its wings1 it opened  its    
bill and performed four different kinds 
of the most beautiful  warbling4 ,it    
then darted down into its nest1 and the 
lid closed upon  it4 ,the moving power  
in this piece of mechanism is said to   
have been  springs which continued their
 action only four minutes4 ,as there was
  no room within so small a figure for  
accommodating pipes to produce  the     
great variety of notes which were       
warbled1 the artist used only  one tube1
 and produced all the variety of sounds 
by shortening and  lengthening it with a
 moveable piston4     #bj ,a similar    

piece of mechanism had been previously  
made by ,m4 le   ,droz4    ,ingenious as
 these pieces of mechanism are1 they    
sink into  insignificance when compared 
with the machinery of ,m4 ,vaucanson1   
which  had previously astonished all    
,europe4 ,his two principal automata    
were  the flute-player1 and the pipe and
 tabor-player4 ,the flute-player  was   
completed in #agcf1 and wherever it was 
exhibited it produced the  greatest     
sensation4 ,when it came to ,paris it   
was received with great  suspicion4 ,the
 ,french savants recollected the story  
of ,m4 ,raisin1  the organist of        
,troyes1 who exhibited an automaton     
player upon the  harpsichord1 which     
astonished the ,french court by the     
variety of  its powers4 ,the curiosity  
of the king could not be restrained1 and
  in consequence of his insisting upon  
examining the mechanism1 there  was     
found in the figure a pretty little     
musician five years of age4  ,it was    
natural1 therefore1 that a similar piece

 of mechanism should  be received with  
some distrust2 but this feeling was soon
 removed  by ,m4 ,vaucanson1 who        
exhibited and explained to a committee  
of the  ,academy of ,sciences the whole 
of the mechanism4 ,this learned body    
was astonished at the ingenuity which it
 displayed2 and they did not  hesitate  
to state1 that the machinery employed   
for producing the sounds  of the flute  
performed in the most exact manner the  
very operations  of the most expert     
flute-player1 and that the artist had   
imitated the  effects produced1 and the 
means employed by nature1 with an       
accuracy  which exceeded all            
expectation4 ,in #agch1 ,m4 ,vaucanson  
published a  memoir1 approved of by the 
,academy1 in which he gave a full       
description  of the machinery employed1 
and of the principles of its            
construction4  ,following this memoir1  
,i shall therefore attempt to give as   
popular a  description of the automaton 
as can be done without lengthened       

details  and numerous figures4    ,the  
body of the flute-player was about #e   
feet high1 and was placed  upon a piece 
of rock1 surrounding a square pedestal  
#d feet high by #c  feet wide4 ,when the
 panel which formed the front of the    
pedestal was  opened1 there was seen on 
the right a clock movement1 which1 by   
the  aid of several wheels1 gave a      
rotatory motion to a steel axis about   
#b feet long1 having cranks at six      
equidistant points of its length1  but  
lying in different directions4 ,to each 
crank was attached a cord1  which       
descended and was fixed by its other end
 to the upper board of a  pair of       
bellows1 #b feet long and #f inches     
wide4 ,six pair of bellows  arranged    
along the bottom of the pedestal were   
then wrought1 or made to  blow in       
succession1 by turning the steel axis4  
,at the upper face of the pedestal1 and 
upon each pair of bellows is a  double  
pulley1 one of whose rims is #c inches  
in diameter1 and the other  #a4 ,the    

cord which proceeds from the crank coils
 round the smaller  of these pulleys1   
and that which is fixed to the upper    
board of the  bellows goes round the    
larger pulley4 ,by this means the upper 
board of  the bellows is made to rise   
higher than if the cords went directly  
from  them to the cranks4    ,round the 
larger rims of three of these pulleys1  
viz4 those on the  right hand1 there are
 coiled three cords1 which1 by means of 
several  smaller pulleys1 terminate in  
the upper boards of other three pair of 
bellows placed on the top of the box4   
,the tension of each cord when it begins
 to raise the board of the  bellows to  
which it is attached1 gives motion to a 
lever placed above  it between the axis 
and the double pulley in the middle and 
lower  region of the box4 ,the other end
 of this lever keeps open the valve in  
the lower board of the bellows1 and     
allows the air to enter freely1  while  
the upper board is rising to increase   
the capacity of the  bellows4 ,by this  

means there is not only power gained1 in
 so far as the  air gains easier        
admission through the valve1 but the    
fluttering noise  produced by the action
 of the air upon the valves is entirely 
avoided1  and the nine pair of bellows  
are wrought with great ease1 and without
  any concussion or noise4    ,these    
nine bellows discharge their wind into  
three different and  separate tubes4    
,each tube receives the wind of three   
bellows1 the upper  boards of one of the
 three pair being loaded with a weight  
of four  pounds1 those of the second    
three pair with a weight of two pounds1 
and those of the other three pair with  
no weight at all4 ,these three  tubes   
ascended through the body of the figure 
and terminated in three  small          
reservoirs placed in its trunk4 ,these  
reservoirs were thus united  into one1  
which1 ascending into the throat1 formed
 by its enlargement  the cavity of the  
mouth terminated by two small lips1     
which rested  upon the whole of the     

flute4 ,these lips had the power of     
opening more  or less1 and by a         
particular mechanism1 they could advance
 or recede  from the hole in the flute4 
,within the cavity of the mouth there is
 a  small moveable tongue for opening   
and shutting the passage for the wind   
through the lips of the figure4    ,the 
motions of the fingers1 lips1 and tongue
 of the figure were  produced by means  
of a revolving cylinder1 thirty inches  
long and  twenty-one in diameter4 ,by   
means of pegs and brass staples fixed in
  fifteen different divisions in its    
circumference1 fifteen different        
levers1 similar to those in a barrel    
organ1 were raised and depressed4       
,seven of these regulated the motions of
 the seven fingers for stopping  the    
holes of the flute1 which they did by   
means of steel chains rising  through   
the body1 and directed by pulleys to the
 shoulder1 elbow1 and  fingers4 ,other  
three of the levers communicating with  
the valves of the  three reservoirs1    

regulated the ingress of the air1 so as 
to produce a  stronger or a weaker tone4
 ,another lever opened the lips so as to
 give  a free passage to the air1 and   
another contracted them for the opposite
  purpose4 ,a third lever drew them     
backwards from the orifice of the       
flute1 and a fourth pushed them forward4
 ,the remaining lever enabled  the      
tongue to stop up the orifice of the    
flute4    ,such is a very brief view of 
the general mechanism by which the      
requisite motions of the flute-player   
were produced4 ,the airs which it       
played were probably equal to those     
executed by a living performer1 and  its
 construction1 as well as its           
performances1 continued for many years  
to delight and astonish the philosophers
 and musicians of ,europe4              
,encouraged by the success of this      
machine1 ,m4 ,vaucanson exhibited in    
#agda other automata1 which were        
equally1 if not more1 admired4 ,one of  
these was the automaton duck1 which     

performed all the motions of that       
animal1 and not only ate its food1 but  
digested it2#ba and the other  was his  
pipe and tabor-player1 a piece of       
mechanism which required  all the       
resources of his fertile genius4 ,having
 begun this machine  before he was aware
 of its peculiar difficulties1 he was   
often about  to abandon it in despair1  
but his patience and his ingenuity      
combined1  enabled him not only to      
surmount every difficulty1 but to       
construct an  automaton which performed 
complete airs1 and greatly excelled the 
most  esteemed performers on the pipe   
and tabor4     #ba ,see ,letter ,,xi4   
,the figure stands on a pedestal1 and is
 dressed like a dancing  shepherd4 ,he  
holds in one hand a flageolet1 and in   
the other the stick  with which he beats
 the tambourine as an accompaniment to  
the airs of  the flageolet1 about twenty
 of which it is capable of performing4  
,the  flageolet has only three holes1   
and the variety of its tones depends    

principally on a proper variation of the
 force of the wind1 and on the          
different degrees with which the        
orifices are covered4 ,these variations 
in the force of the wind required to be 
given with a rapidity which  the ear can
 scarcely follow1 and the articulation  
of the tongue was  required for the     
quickest notes1 otherwise the effect was
 far from  agreeable4 ,as the human     
tongue is not capable of giving the     
requisite  articulations to a rapid     
succession of notes1 and generally slurs
  over one-half of them1 the automaton  
was thus able to excel the best         
performers1 as it played complete airs  
with articulations of the tongue  at    
every note4    ,in constructing this    
machine1 ,m4 ,vaucanson observed that   
the flageolet  must be a most fatiguing 
instrument for the human lungs1 as the  
muscles  of the chest must make an      
effort equal to fifty-six pounds in     
order to  produce the highest notes4 ,a 
single ounce was sufficient for the     

lowest  notes3 so that we may1 from this
 circumstance1 form an idea of the      
variety of intermediate effects required
 to be produced4    ,while ,m4          
,vaucanson was engaged in the           
construction of these wonderful         
machines1 his mind was filled with the  
strange idea of constructing  an        
automaton containing the whole mechanism
 of the circulation of  the blood4 ,from
 some birds which he made1 he was       
satisfied of its  practicability2 but as
 the whole vascular system required to  
be made  of elastic gum or caoutchouc1  
it was supposed that it could only be   
executed in the country where the       
caoutchouc tree was indigenous4  ,louis 
,,xvi4 took a deep interest in the      
execution of this machine4  ,it was     
agreed that a skilful anatomist should  
proceed to ,guiana to  superintend the  
construction of the blood-vessels1 and  
the king  had not only approved of1 but 
had given orders for1 the voyage4       
,difficulties1 however1 were thrown in  

the way1 ,vaucanson became  disgusted1  
and the scheme was abandoned4    ,the   
two automata which we have described    
were purchased by ,professor  ,bayreuss 
of ,helmstadt2 but we have not been able
 to learn whether or  not they still    
exist4    ,illustration3 ,fig4 #dh4     
,towards the end of the eighteenth      
century a bold and almost successful    
attempt was made to construct a talking 
automaton4 ,in the year #aggi1  the     
,imperial ,academy of ,sciences at ,st4 
,petersburgh proposed1 as the  subject  
of one of their annual prizes1 an       
inquiry into the nature  of the vowel   
sounds1 ,a1 ,e1 ,i1 ,o1 and ,u1 and the 
construction of an  instrument for      
artificially imitating them4 ,this prize
 was gained by  ,m4 ,kratzenstein1 who  
showed that all the vowels could be     
distinctly  pronounced by blowing       
through a reed into the lower ends of   
the pipes  of the annexed figures1 as   
shown in ,fig4 #dh1 where the           
corresponding  vowels are marked on the 

different pipes4 ,the vowel ,i is       
pronounced by  merely blowing into the  
pipe a b1 of the pipe marked ,i1 without
 the  use of a reed4    ,illustration3  
,fig4 #di4    ,about the same time that 
,kratzenstein was engaged in these      
researches1  ,m4 ,kempelen of ,vienna1 a
 celebrated mechanician1 was occupied   
with the  same subject4 ,in his first   
attempt he produced the vowel sounds1 by
  adapting a reed ,r1 ,fig4 #di1 to the 
bottom of a funnel-shaped cavity  ,a ,b1
 and placing his hand in various        
positions within the funnel4  ,this     
contrivance1 however1 was not fitted for
 his purpose1 but after  long study1 and
 a diligent examination of the organs of
 speech1 he  contrived a hollow oval    
box1 divided into two portions attached 
by a  hinge so as to resemble jaws4     
,this box received the sound which      
issued  from the tube connected with the
 reed1 and by opening and closing the   
jaws1 he produced the sounds1 ,a1 ,o1   
,,ou1 and an imperfect ,e1 but no       

indications of an ,i4 ,after two years' 
labour he succeeded in obtaining  from  
different jaws the sounds of the        
consonants ,p1 ,m1 ,l1 and by means  of 
these vowels and consonants1 he could   
compose syllables and words1  such as   
mama1 papa1 aula1 lama1 mulo4 ,the      
sounds of two  adjacent letters1        
however1 ran into each other1 and an    
aspiration  followed some of the        
consonants2 so that1 instead of papa1   
the word  sounded phaa-ph-a2 these      
difficulties he contrived with much     
labour  to surmount1 and he found it    
necessary to imitate the human organs of
  speech by having only one mouth and   
one glottis4 ,the mouth consisted  of a 
funnel1 or bell-shaped piece of elastic 
gum1 which approximated1  by its        
physical properties1 to the softness and
 flexibility of the  human organs4#bb   
,to the mouth-piece was added a nose    
made of two tin  tubes1 which           
communicated with the mouth4 ,when both 
these tubes were  open1 and the         

mouth-piece closed1 a perfect ,m was    
produced2 and when  one was closed and  
the other open1 an ,n was sounded4 ,m4  
,kempelen could  have succeeded in      
obtaining the four letters ,d1 ,g1 ,k1  
,t1 but1 by using  a ,p instead of them1
 and modifying the sound in a particular
 manner1  he contrived to deceive the   
ear by a tolerable resemblance of these 
letters4     #bb ,had ,m4 ,kempelen     
known the modern discovery of giving    
glue any   degree of softness1 by mixing
 it with molasses or sugar1 which is    
always absorbing moisture from the      
atmosphere1 he might have obtained   a  
still more perfect imitation of the     
human organs4    ,there seems to be no  
doubt that he at last was able to       
produce entire  words and sentences1    
such as opera1 astronomy1               
,constantinopolis1  ,vous tes mon ami1  
,je vous aime de tout mon cur1 ,venez   
avec moi   ,paris1 ,leopoldus secundus1 
,romanorum imperator semper ,augustus1  
c41  but he never fitted up a speaking  

figure2 and probably1 from being        
dissatisfied with the general result of 
his labours1 he exhibited only  to his  
private friends the effects of the      
apparatus1 which was fitted  up in the  
form of a box4    ,this box was         
rectangular1 and about three feet long1 
and was placed  upon a table1 and       
covered with a cloth4 ,when any         
particular word was  mentioned by the   
company1 ,m4 ,kempelen caused the       
machine to pronounce  it1 by introducing
 his hands beneath the cloth1 and       
apparently giving  motion to some parts 
of the apparatus4 ,mr4 ,thomas          
,collinson1 who had  seen this machine  
in ,london1 mentions1 in a letter to    
,dr4 ,hutton1 that  he afterwards saw it
 at ,m4 ,kempelen's own house in        
,vienna1 and that he  then gave it the  
same word to be pronounced which he gave
 it in ,london1  viz4 the word          
,exploitation1 which1 he assures us1 it 
again distinctly  pronounced with the   
,french accent4    ,m4 ,kratzenstein    

seems to have been equally unsuccessful2
 for though he  assured ,m4 de ,lalande1
 when he saw him in ,paris1 in #aghf1   
that he had  made a machine which could 
speak pretty well1 and though he showed 
him  some of the apparatus by which it  
could sound the vowels1 and even such   
syllables as papa and mama1 yet there is
 no reason to believe that  he had      
accomplished more than this4    ,the    
labours of ,kratzenstein and ,kempelen  
have been recently pursued  with great  
success by our ingenious countryman1    
,mr4 ,willis1 of  ,cambridge4 ,in       
repeating ,kempelen's experiment1 shown 
in ,fig4 #di1 he  used a shallower      
cavity1 such as that in ,fig4 #ej1 and  
found that he  could entirely dispense  
with the introduction of the hand1 and  
could  obtain the whole series of vowels
 by sliding a flat board ,c ,d over the 
mouth of the cavity4 ,mr4 ,willis then  
conceived the idea of adapting to  the  
reed cylindrical tubes1 whose length    
could be varied by sliding  joints4     

,when the tube was greatly less than the
 length of a stopped  pipe in unison    
with the reed1 it sounded ,i1 and by    
increasing the  length of the tube1 it  
gave ,e1 ,a1 ,o1 and ,u1 in succession4 
,but what was  very unexpected1 when the
 tube was so much lengthened as to be #a
 times  the length of a stopped pipe in 
unison with the reed1 the vowels began  
to be again sounded in an inverted      
order1 viz4 ,u1 ,o1 ,a1 ,e1 and then    
again in a direct order1 ,i1 ,e1 ,a1 ,o1
 ,u1 when the length of the tube was    
equal to twice that of a stopped pipe1  
in unison with the reed4                
,illustration3 ,fig4 #ej4    ,some      
important discoveries have been recently
 made by ,m4 ,savart  respecting the    
mechanism of the human voice2#bc and we 
have no doubt  that1 before another     
century is completed1 a ,talking and a  
,singing  machine will be numbered among
 the conquests of ,science4     #bc ,see
 ,edinburgh ,journal of ,science1 ,no4  
viii41 p4 #bjj4          ,,letter ,,ix4 

,singular effects in nature depending on
 sound--,permanent character   of       
speech--,influence of great elevations  
on the character of   sounds1 and on the
 powers of speech--,power of sound in   
throwing   down buildings--,dog killed  
by sound--,sounds greatly changed under 
particular circumstances--,great        
audibility of sounds during   the night 
explained--,sounds deadened in media of 
different   densities--,illustrated in  
the case of a glass of champagne--and   
in that of new-fallen snow--,remarkable 
echoes--,reverberations of              
thunder--,subterranean                  
noises--,remarkable one at the          
,solfaterra--,echo   at the ,menai      
suspension bridge--,temporary deafness  
produced in                             
diving-bells--,inaudibility of          
particular sounds to particular         
ears--,vocal powers of the statue of    
,memnon--,sounds in granite             
rocks--,musical mountain of ,el-,nakous4
      ,although1 among the phenomena of 

the material world1 there is scarcely   
one which1 when well considered1 is not 
an object of wonder1 yet those  which we
 have been accustomed to witness from   
our infancy lose all  their interest    
from the frequency of their occurrence1 
while to the  natives of other countries
 they are unceasing objects of          
astonishment  and delight4 ,the         
inhabitant of a tropical climate is     
confounded at  the sight of falling     
snow1 and he almost discredits the      
evidence of  his senses when he sees a  
frozen river carrying loaded waggons on 
its  surface4 ,the diffusion of         
knowledge by books1 as well as by       
frequent  communication between the     
natives of different quarters of the    
globe1  has deprived this class of local
 wonders of their influence1 and the    
,indian and the ,scandinavian can visit 
each other's lands without any  violent 
excitement of surprise4 ,still1 however1
 there are phenomena  of rare           
occurrence1 of which no description can 

convey the idea1 and  which continue to 
be as deeply marked with the marvellous 
as if they  had been previously unknown4
 ,among these we may rank the remarkable
  modifications which sound undergoes in
 particular situations and under        
particular circumstances4    ,in the    
ordinary intercourse of life1 we        
recognize individuals as  much by their 
voice as by the features of their face  
and the form of  their body4 ,a friend  
who has been long absent will often     
stand before  us as a stranger1 till his
 voice supplies us with the full power  
of  recognition4 ,the brand imprinted by
 time on his outer form may have        
effaced the youthful image which the    
memory had cherished1 but the  original 
character of his voice and its yet      
remembered tones will  remain           
unimpaired4    ,an old friend with a new
 face is not more common in its moral   
than in  its physical acceptation2 and  
though the sagacity of proverbial wisdom
  has not supplied us with the          

counterpart in relation to the human    
voice1 yet the influence of its         
immutability over the mind has been     
recorded by the poet in some of his most
 powerful conceptions4 ,when  ,manfred  
was unable to recognize in the hectic   
phantom of ,astarte the  endeared       
lineaments of the being whom he loved1  
the mere utterance of  his name recalled
 8the voice which was his music10 and   
invested her  with the desired reality4 
,say on1 say on--      ,i live but in   
the sound--,it is thy voice6            
,,byron4    ,the permanence of character
 thus impressed upon speech exists only 
in  those regions to whose atmosphere   
our vocal organs are adapted4 ,if       
either the speaker or the hearer is     
placed in air differing greatly in      
density from that to which they are     
accustomed1 the voice of the one  will  
emit different sounds1 or the same      
sounds will produce a different         
impression on the ear of the other4 ,but
 if both parties are placed in  this new

 atmosphere1 their tones of             
communication will suffer the most      
remarkable change4 ,the two extreme     
positions1 where such effects become    
sufficiently striking1 are in the       
compressed air of the diving-bell1  when
 it is immersed to a great depth in the 
sea1 or in the rarefied  atmosphere     
which prevails on the summit of the     
,himalaya or the ,andes4    ,in the     
region of common life1 and even at the  
stillest hour of night1  the ear seldom 
rests from its toils4 ,when the voice of
 man and the  bustle of his labours have
 ceased1 the sounds of insect life are  
redoubled2 the night breeze awakens     
among the rustling leaves1 and the      
swell of the distant ocean1 and the     
sounds of the falling cataract or  of   
the murmuring brook1 fill the air with  
their pure and solemn music4  ,the      
sublimity of deep silence is not to be  
found even in the steppes  of the       
,volga1 or in the forests of the        
,orinoco4 ,it can be felt only in  those

 lofty regions        ,where the tops of
 the ,andes1        ,shoot soaringly    
forth4    ,as the traveller rises above 
the limit of life and motion1 and enters
  the region of habitual solitude1 the  
death-like silence which prevails       
around him is rendered still more       
striking by the diminished density  of  
the air which he breathes4 ,the voice of
 his fellow traveller ceases  to be     
heard even at a moderate distance1 and  
sounds which would stun  the ear at a   
lower level make but a feeble           
impression4 ,the report of  a pistol on 
the top of ,mont ,blanc is no louder    
than that of an ,indian  cracker4 ,but  
while the thinness of the air thus      
subdues the loudest  sounds1 the voice  
itself undergoes a singular change3 the 
muscular  energy by which we speak      
experiences a great diminution1 and our 
powers  of utterance1 as well as our    
power of hearing1 are thus singularly   
modified4 ,were the magician1 therefore1
 who is desirous to impress upon  his   

victim or upon his pupil the conviction 
of his supernatural power1  to carry    
him1 under the injunction of silence1   
----------------------------- to breathe
      ,the difficult air of the iced    
mountain's top1      ,where the birds   
dare not build1 nor insect's wing       
,flit o'er the herbless granite1    he  
would experience little difficulty in   
asserting his power over  the elements1 
and still less in subsequently          
communicating the same  influence to his
 companion4    ,but though the air at   
the tops of our highest mountains is    
scarcely  capable of transmitting sounds
 of ordinary intensity1 yet sounds of   
extraordinary power force their way     
through its most attenuated strata4  ,at
 elevations where the air is three      
thousand times more rare than  that     
which we breathe1 the explosion of      
meteors is heard like the  sound of     
cannon on the surface of the earth1 and 
the whole air is often  violently       
agitated by the sound4 ,this fact alone 

may give us some idea  of the tremendous
 nature of the forces which such        
explosions create1  and it is fortunate 
for our species that they are confined  
to the upper  regions of the atmosphere4
 ,if the same explosions were to take   
place in  the dense air which rests upon
 the earth1 our habitations and our     
lives  would be exposed to the most     
imminent peril4    ,buildings have often
 been thrown down by violent concussions
 of the  air1 occasioned either by the  
sound of great guns or by loud thunder1 
and the most serious effects upon human 
and animal life have been  produced by  
the same cause4 ,most persons have      
experienced the stunning  pain produced 
in the ear1 when placed near a cannon   
that is discharged4  ,deafness has      
frequently been the result of such      
sudden concussions1  and1 if we may     
reason from analogy1 death itself must  
often have  been the consequence4 ,when 
peace was proclaimed in ,london1 in     
#afig1  two troops of horse were        

dismounted and drawn up in line in order
 to  fire their volleys4 ,opposite the  
centre of the line was the door of a    
butcher's shop1 where there was a large 
mastiff dog of great courage4  ,this dog
 was sleeping by the fire1 but when the 
first volley was fired1  it immediately 
started up1 ran into another room1 and  
hid itself under  a bed4 ,on the firing 
of the second volley1 the dog rose1 ran 
several  times about the room trembling 
violently1 and apparently in great      
agony4 ,when the third volley was fired1
 the dog ran about once or twice  with  
great violence and instantly fell down  
dead1 throwing up blood  from his mouth 
and nose4    ,sounds of known character 
and intensity are often singularly      
changed  even at the surface of the     
earth1 according to the state of the    
ground  and the conditions of the       
clouds4 ,on the extended heath1 where   
there  are no solid objects capable of  
reflecting or modifying sound1 the      
sportsman must frequently have noticed  

the unaccountable variety of  sounds    
which are produced by the report of his 
fowling-piece4 ,sometimes  they are flat
 and prolonged1 at other times short and
 sharp1 and  sometimes the noise is so  
strange that it is referred to some     
mistake  in the loading of the gun4     
,these variations1 however1 arise       
entirely  from the state of the air1 and
 from the nature and proximity of the   
superjacent clouds4 ,in pure air of     
uniform density the sound is sharp  and 
soon over1 as the undulations of the air
 advance without any  interrupting      
obstacles4 ,in a foggy atmosphere1 or   
where the vapours  produced by heat are 
seen dancing as it were in the air1 the 
sound is  dull and prolonged2 and when  
these clouds are immediately over-head1 
a  succession of echoes from them       
produces a continued or reverberating   
sound4 ,when the ,french astronomers    
were determining the velocity of  sound 
by firing great guns1 they observed that
 the report was always  single and sharp

 under a perfectly clear sky1 but       
indistinct1 and  attended by a          
long-continued roll like thunder1 when a
 cloud covered  a considerable part of  
the horizon4 ,it is no doubt owing to   
the same  cause1 namely1 the reflexion  
from the clouds1 that the thunder rolls 
through the heavens1 as if it were      
produced by a succession of electric    
explosions4    ,the great audibility of 
sounds during the night is a phenomenon 
of  considerable interest1 and one which
 had been observed even by the          
ancients4 ,in crowded cities or in their
 vicinity1 the effect was  generally    
ascribed to the rest of animated beings2
 while in localities  where such an     
explanation was inapplicable1 it was    
supposed to arise  from a favourable    
direction of the prevailing wind4 ,baron
 ,humboldt  was particularly struck with
 this phenomenon when he first heard the
  rushing of the great cataracts of the 
,orinoco in the plain which  surrounds  
the ,mission of the ,apures4 ,these     

sounds he regarded as  three times      
louder during the night than during the 
day4 ,some authors  ascribed this fact  
to the cessation of the humming of      
insects1 the  singing of birds1 and the 
action of the wind on the leaves of the 
trees1 but ,m4 ,humboldt justly         
maintains that this cannot be the cause 
of it on the ,orinoco1 where the buzz of
 insects is much louder in the  night   
than in the day1 and where the breeze   
never rises till after  sunset4 ,hence  
he was led to ascribe the phenomenon to 
the perfect  transparency and uniform   
density of the air1 which can exist only
 at  night after the heat of the ground 
has been uniformly diffused through  the
 atmosphere4 ,when the rays of the sun  
have been beating on the  ground during 
the day1 currents of hot air of         
different temperatures1  and            
consequently of different densities1 are
 constantly ascending from  the ground  
and mixing with the cold air above4 ,the
 air thus ceases  to be a homogeneous   

medium1 and every person must have      
observed the  effects of it upon objects
 seen through it which are very         
indistinctly  visible1 and have a       
tremulous motion1 as if they were       
8dancing in  the air40 ,the very same   
effect is perceived when we look at     
objects  through spirits and water that 
are not perfectly mixed1 or when we view
  distant objects over a red-hot poker  
or over a flame4 ,in all these  cases   
the light suffers refraction in passing 
from a medium of one  density into a    
medium of a different density1 and the  
refracted rays  are constantly changing 
their direction as the different        
currents rise  in succession4 ,analogous
 effects are produced when sound passes 
through  a mixed medium1 whether it     
consists of two different mediums or of 
one  medium where portions of it have   
different densities4 ,as sound moves    
with different velocities through media 
of different densities1 the  wave which 
produces the sound will be partly       

reflected in passing from  one medium to
 the other1 and the direction of the    
transmission wave  changed3 and hence in
 passing through such media different   
portions of  the wave will reach the ear
 at different times1 and thus destroy   
the  sharpness and distinctness of the  
sound4 ,this may be proved by many      
striking facts4 ,if we put a bell in a  
receiver containing a mixture of        
hydrogen gas and atmospheric air1 the   
sound of the bell can scarcely be       
heard4 ,during a shower of rain or of   
snow1 noises are greatly deadened2  and 
when sound is transmitted along an iron 
wire or an iron pipe of  sufficient     
length1 we actually hear two sounds1 one
 transmitted more  rapidly through the  
solid1 and the other more slowly through
 the air4  ,the same property is well   
illustrated by an elegant and easily    
repeated  experiment of ,chladni's4     
,when sparkling champagne is poured into
 a tall  glass till it is half full1 the
 glass loses its power of ringing by a  

stroke upon its edge1 and emits only a  
disagreeable and puffy sound4  ,this    
effect will continue while the wine is  
filled with bubbles of  air1 or as long 
as the effervescence lasts2 but when the
 effervescence  begins to subside the   
sound becomes clearer and clearer1 and  
the glass  rings as usual when the      
air-bubbles have vanished4 ,if we       
reproduce  the effervescence by stirring
 the champagne with a piece of bread1   
the  glass will again cease to ring4    
,the same experiment will succeed with  
other effervescing fluids4    ,the      
difference in the audibility of sounds  
that pass over homogeneous  and over    
mixed media is sometimes so remarkable  
as to astonish those  who witness it4   
,the following fact is given on the     
evidence of an  officer who observed    
it3--,when the ,british and the         
,american forces  were encamped on each 
side of a river1 the outposts were so   
near1 that  the form of individuals     
could be easily distinguished4 ,an      

,american  drummer made his appearance1 
and began to beat his drum2 but though  
the motion of his arms was distinctly   
seen1 not a single sound reached  the   
ear of the observer4 ,a coating of snow 
that had newly fallen upon  the ground1 
and the thickness of the atmosphere1 had
 conspired to  obstruct the sound4 ,an  
effect the very reverse of this is      
produced by  a coating of glazed or     
hardened snow1 or by an extended surface
 of ice  or water4 ,lieutenant ,foster  
was able to carry on a conversation with
  a sailor across ,port ,bowen ,harbour1
 a distance of no less than a mile  and 
a quarter1 and the sound of great guns  
has been heard at distances  varying    
from #abj to #bjj miles4 ,over hard and 
dry ground of a uniform  character1 or  
where a thin soil rests upon a          
continuous stratum of  rock1 the sound  
is heard at a great distance1 and hence 
it is the  practice among many ,eastern 
tribes to ascertain the approach of an  
enemy by applying the ear to the ground4

    ,many remarkable phenomena in the   
natural world are produced by the       
reflexion and concentration of sound4   
,every person is familiar with  the     
ordinary echo which arises from the     
reflexion of sound from an  even        
surface1 such as the face of a wall1 of 
a house1 of a rock1 of  a hill1 or of a 
cloud4 ,as sound moves at the rate of   
#ajij feet in a  second1 and as the     
sound which returns to the person who   
emits it has  travelled over a space    
equal to twice his distance from the    
reflecting  surface1 the distance in    
feet of the body which occasions the    
echo may  be readily found by           
multiplying #ede by the number of       
seconds which  elapse between the       
emission of the sound and its return in 
the form of  an echo4 ,this kind of     
echo1 where the same person is the      
speaker and  the hearer1 never takes    
place1 unless when the observer is      
immediately  in front of the reflecting 
surface1 or when a line drawn from his  

mouth  to the flat surface is nearly    
perpendicular to it1 because in this    
case alone the wave of sound is         
reflected in the very same direction    
from the wall in which it reaches it4   
,if the speaker places himself  on one  
side of this line1 then the echo will be
 heard most distinctly  by another      
person as far on the other side of it1  
because the waves  of sound are         
reflected like light1 so that the angle 
of incidence or  the inclination at     
which the sound falls upon the reflected
 surface  is equal to the angle of      
reflexion1 or the inclination at which  
the  sound is returned from the wall4   
,if two persons1 therefore1 are placed  
before the reflecting wall1 the one will
 hear the echo of the sound  emitted by 
the other1 and obstacles may intervene  
between these two  persons1 so that     
neither of them hears the direct sound  
emitted by the  other2 in the same      
manner as the same persons similarly    
placed before  a looking-glass would see

 each other distinctly by reflexion1    
though  objects might obstruct their    
direct view of each other4    ,hitherto 
we have supposed that there is only one 
reflecting surface1  in which case there
 will be only one echo2 but if there are
 several  reflecting surfaces1 as in the
 case in an amphitheatre of mountains1  
or during a thunder-storm1 where there  
are several strata or masses  of clouds2
 or if there are two parallel or        
inclined surfaces between  which the    
sound can be repeatedly reflected1 or if
 the surface is  curved1 so that the    
sound reflected from one part falls upon
 another  part1 like the sides of a     
polygon inscribed in a circle1--in all  
these  cases there will be numerous     
echoes1 which produce a very singular   
effect4 ,nothing can be more grand and  
sublime than the primary and  secondary 
echoes of a piece of ordnance discharged
 in an amphitheatre  of precipitous     
mountains4 ,the direct or primary echoes
 from each  reflecting surface reach the

 ear in succession1 according to their  
different distances1 and these are      
either blended with or succeeded  by the
 secondary echoes1 which terminate in a 
prolonged growl1 ending  in absolute    
silence4 ,of the same character are the 
reverberated claps  of a thunderbolt    
reflected from the surrounding clouds1  
and dying  away in the distance4 ,the   
echo which is produced by parallel walls
  is finely illustrated at the ,marquis 
of ,simonetta's villa near ,milan1      
which has been described by ,addison and
 ,keysler1 and which we believe  is that
 described by ,mr4 ,southwell in the    
,philosophical ,transactions  for #agdf4
 ,perpendicular to the main body of this
 villa there extend two  parallel wings 
about fifty-eight paces distant from    
each other1 and the  surfaces of which  
are unbroken either with doors or       
windows4 ,the sound  of the human voice1
 or rather a word quickly pronounced1 is
 repeated  above forty times1 and the   
report of a pistol from fifty-six to    

sixty  times4 ,the repetitions1 however1
 follow in such rapid succession that   
it is difficult to reckon them1 unless  
early in the morning before the  equal  
temperature of the atmosphere is        
disturbed1 or in a calm1 still  evening4
 ,the echoes appear to be best heard    
from a window in the main  building     
between the two projecting walls1 from  
which the pistol also  is fired4 ,dr4   
,plot mentions an echo in ,woodstock    
,park which repeats  seventeen syllables
 by day and twenty by night4 ,an echo on
 the north  side of ,shipley church1 in 
,sussex1 repeats twenty-one syllables4  
,sir  ,john ,herschel mentions an echo  
in the ,manfroni palace at ,venice1     
where  a person standing in the centre  
of a square room about twenty-five  feet
 high1 with a concave roof1 hears the   
stamp of his foot repeated  a great many
 times2 but as his position deviates    
from the centre1 the  echoes become     
feebler1 and at a short distance        
entirely cease4 ,the  same phenomenon1  

he remarks1 occurs in the large room of 
the library  of the museum at ,naples4  
,m4 ,genefay has described1 as existing 
near  ,rouen1 a curious oblique echo    
which is not heard by the person who    
emits the sound4 ,a person who sings    
hears only his own voice1 while  those  
who listen hear only the echo1 which    
sometimes seems to approach1  and at    
other times seems to recede from the    
ear2 one person hears a  single sound1  
another several sounds1 and one hears it
 on the right1  and another on the left1
 the effect always changing as the      
hearer  changes his position4 ,dr4      
,birch has described an extraordinary   
echo at  ,roseneath1 in ,argyleshire1   
which certainly does not now exist4     
,when  eight or ten notes were played   
upon a trumpet1 they were correctly     
repeated1 but on a key a third lower4   
,after a short pause1 another           
repetition of the notes was heard in a  
still lower tone1 and after  another    
short interval they were repeated in a  

still lower tone4    ,in the same manner
 as light is always lost by reflexion1  
so the  waves of sound are enfeebled by 
reflexion from ordinary surfaces1  and  
the echo is in such cases fainter than  
the original sound4 ,if  the reflecting 
surface1 however1 is circular1 sound may
 be condensed  and rendered stronger in 
the same manner as light4 ,i have seen a
  fine example of this1 in the circular 
turn of a garden wall nearly  a mile    
distant from a weir across a river4     
,when the air is pure and  homogeneous1 
the rushing sound of the water is       
reflected from the  hollow surface of   
the wall1 and concentrated in a focus1  
the place of  which the ear can easily  
discover from the intensity of the sound
 being  there a maximum4 ,a person not  
acquainted with the locality conceives  
that the rushing noise is on the other  
side of the wall4    ,in whispering     
galleries1 or places where the lowest   
whispers are  carried to distances at   
which the direct sound is inaudible1 the

 sound  may be conveyed in two ways1    
either by repeated reflexions from a    
curved surface in the direction of the  
sides of a polygon inscribed  in a      
circle1 or where the whisperer is in the
 focus of one reflecting  surface1 and  
the hearer in the focus of another      
reflecting surface1  which is placed so 
as to receive the reflected sounds4 ,the
 first of  these ways is exemplified in 
the whispering gallery of ,st4 ,paul's1 
and in the octagonal gallery of         
,gloucester cathedral1 which conveys  a 
whisper seventy-five feet across the    
nave2 and the second in the  baptistery 
of a church in ,pisa1 where the         
architect1 ,giovanni ,pisano1  is said  
to have constructed the cupola on       
purpose4 ,the cupola has an  elliptical 
form1 and when one person whispers in   
one focus1 it is  distinctly heard by   
the person placed in the other focus1   
but not by  those who are placed between
 them4 ,the sound first reflected passes
  across the cupola1 and enters the ears

 of the intermediate persons1  but it is
 too feeble to be heard till it has been
 condensed by a  second reflexion to the
 other focus of ellipse4 ,a naval       
officer1  who travelled through ,sicily 
in the year #ahbd1 gives an account of  
a powerful whispering place in the      
cathedral of ,girgenti1 where the       
slightest whisper is carried with       
perfect distinctness through a  distance
 of two hundred and fifty feet1 from the
 great western door to  the cornice     
behind the high altar4 ,by an           
unfortunate coincidence1 the  focus of  
one of the reflecting surfaces was      
chosen for the place of the             
confessional2 and when this was         
accidentally discovered1 the lovers  of 
secrets resorted to the other focus1 and
 thus became acquainted  with           
confessions of the gravest import4 ,this
 divulgence of scandal  continued for a 
considerable time1 till the eager       
curiosity of one  of the dilettanti was 
punished1 by hearing his wife's avowal  

of her  own infidelity4 ,this           
circumstance gave publicity to the      
whispering  peculiarity of the          
cathedral1 and the confessional was     
removed to a  place of greater secrecy4 
,illustration3 ,fig4 #ea4    ,an echo of
 a very peculiar character has been     
described by ,sir ,john  ,herschell in  
his ,treatise on ,sound1 as produced by 
the suspension  bridge across the ,menai
 strait in ,wales4 8,the sound of a blow
 with a  hammer10 says he1 8on one of   
the main piers1 is returned in          
succession  from each of the cross-beams
 which support the road-way1 and from   
the  opposite pier at a distance of five
 hundred and seventy-six feet2 and  in  
addition to this1 the sound is many     
times repeated between the  water and   
the road-way4 ,the effect is a series of
 sounds which may be  thus written3 the 
first return is sharp and strong from   
the road-way  over-head2 the rattling   
which succeeds dies away rapidly1 but   
the  single repercussion from the       

opposite pier is very strong1 and is    
succeeded by a faint palpitation1       
repeating the sound at the rate of      
twenty-eight times in five seconds1 and 
which1 therefore corresponds to  a      
distance of a hundred and eighty-four   
feet1 or very nearly the double         
interval from the road-way to the water4
 ,thus it appears that in the           
repercussion between the water and      
road-way1 that from the latter only     
affects the ear1 the line drawn from the
 auditor to the water being  too oblique
 for the sound to diverge sufficiently  
in that direction4  ,another peculiarity
 deserves especial notice1 namely1 that 
the echo  from the opposite pier is best
 heard when the auditor stands precisely
  opposite to the middle of the breadth 
of the pier1 and strikes just  on that  
point4 ,as it deviates to one or the    
other side1 the return is               
proportionally fainter1 and is scarcely 
heard by him when his station  is a     
little beyond the extreme edge of the   

pier1 though another person1  stationed 
7on the same side of the water7 at an   
equal distance from the  central point1 
so as to have the pier between them1    
hears it well40    ,a remarkable        
subterranean echo is often heard when   
the hoofs of a horse  or the wheels of a
 carriage pass over particular spots of 
ground4 ,this  sound is frequently very 
similar to that which is produced in    
passing  over an arch or vault1 and is  
commonly attributed to the existence of 
natural or artificial caves beneath4 ,as
 such caves have often been  constructed
 in times of war as places of security  
for persons and  property1 many         
unavailing attempts have been made to   
discover hidden  treasures where their  
locality seemed to be indicated by      
subterraneous  sounds4 ,but though these
 sounds are sometimes produced by       
excavations  in the ground1 yet they    
generally arise from the nature of the  
materials of which the ground is        
composed1 and from their manner of      

combination4 ,if the hollow of a road   
has been filled up with broken  rock1 or
 with large waterworn stones1 having    
hollows either left  entirely empty1 or 
filled up with materials of different   
density1 then  the sound will be        
reflected in passing from the loose to  
the dense  materials1 and there will    
arise a great number of echoes reaching 
the  ear in rapid succession1 and       
forming by their union a hollow rumbling
  sound4 ,this principle has been very  
successfully applied by ,sir ,john      
,herschell to explain the subterranean  
sounds with which every traveller  is   
familiar who has visited the            
,solfaterra1 near ,naples4 ,when the    
ground at a particular place is struck  
violently by throwing a large  stone    
against it1 a peculiar hollow sound is  
distinctly heard4 ,this  sound has been 
ascribed by some geologists to the      
existence of a great  vault             
communicating with the ancient seat of  
the volcano1 by other  writers to a     

reverberation from the surrounding hills
 with which it  is nearly concentric1   
and by others to the porosity of the    
ground4  ,dr4 ,daubeny1 who says that   
the hollow sound is heard when any part 
of the ,solfaterra is struck1 accounts  
for it by supposing that the  hill is   
not made up of one entire rock1 but of a
 number of detached  blocks1 which1     
hanging as it were by each other1 form a
 sort of vault  over the abyss within   
which the volcanic operations are going 
on4#bd  ,mr4 ,forbes1 who has given the 
latest and most interesting description 
of this singular volcano1#be agrees in  
opinion with ,dr4 ,daubeny2  while ,mr4 
,scrope#bf and ,sir ,john ,herschell    
concur in opinion that  no such cavities
 exist4 8,it seems most probable10 says 
the latter1  8that the hollow           
reverberation is nothing more than an   
assemblage  of partial echoes arising   
from the reflexion of successive        
portions  of the original sound1 in its 
progress through the soil at the        

innumerable half-coherent surfaces      
composing it3 were the whole soil  a    
mass of sand1 these reflexions would be 
so strong and frequent as  to destroy   
the whole impulse in too short an       
interval to allow of a  distinguishable 
after-sound4 ,it is a case analogous to 
that of a strong  light thrown into a   
milky medium or smoky atmosphere2 the   
whole medium  appears to shine with a   
nebulous undefined light4 ,this is to   
the eye  what such a hollow sound is to 
the ear40#bg     #bd ,description of    
,volcanoes1 p4 #agj4     #be ,edinburgh 
,journal of ,science1 ,new ,series1 ,no4
 i41 p4 #abd4     #bf ,considerations on
 ,volcanoes1 and ,edinburgh ,journal of 
,science1   ,no4 xx41 p4 #bfa1 and ,no4 
xiv41 p4 #bfe4     #bg ,art4 ,,sound1   
,encycl4 ,metrop41  #aaj4    ,it has    
been recently shown by ,m4 ,savart1 that
 the human ear is so  extremely sensible
 as to be capable of appreciating sounds
 which  arise from about twenty-four    
thousand vibrations in a second1 and    

consequently that it can hear a sound   
which lasts only the twenty-four        
thousandth part of a second4 ,vibrations
 of such frequency afford only  a shrill
 squeak or chirp2 and ,dr4 ,wollaston   
has shown that there are  many          
individuals with their sense of hearing 
entire1 who are altogether  insensible  
to such acute sounds1 though others are 
painfully affected  by them4 ,nothing1  
as ,sir ,john ,herschell remarks1 can be
 more surprising  than to see two       
persons1 neither of them deaf1 the one  
complaining of  the penetrating         
shrillness of a sound1 while the other  
maintains there  is no sound at all4    
,dr4 ,wollaston has also shown that this
 is true also  of very grave sounds2 so 
that the hearing or not hearing of      
musical  notes at both extremities of   
the scale seems to depend wholly on the 
pitch or frequency of vibration         
constituting the note1 and not upon the 
intensity or loudness of the noise4     
,this affection of the ear sometimes    

appears in cases of common deafness1    
where a shrill tone of voice1 such  as  
that of women and children1 is often    
better heard than the loud and  deeper  
tone of men4    ,dr4 ,wollaston         
remarked1 that when the mouth and nose  
are shut1 the  tympanum or drum of the  
ear may be so exhausted by a forcible   
attempt  to take breath by the expansion
 of the chest1 the pressure of the      
external air upon the membrane gives it 
such a tension1 that the ear  becomes   
insensible to grave tones1 without      
losing in any degree the  perception of 
sharper sounds4 ,dr4 ,wollaston found1  
that after he had  got into the habit of
 making the experiment1 so as to be able
 to  produce a great degree of          
exhaustion1 his ears were insensible to 
all sounds below ,f1 marked by the bass 
clef4 8,if ,i strike the table  before  
me10 says he1 8with the end of my       
finger1 the whole board sounds  with a  
deep dull note4 ,if ,i strike it with my
 nail1 there is also at  the same time a

 sharp sound produced by quicker        
vibrations of parts  around the point of
 contact4 ,when the ear is exhausted1 it
 hears only  the latter sound1 without  
perceiving in any degree the deeper note
 of  the whole table4 ,in the same      
manner1 in listening to the sound of a  
carriage1 the deeper rumbling noise of  
the body is no longer heard by  an      
exhausted ear2 but the rattle of a chain
 or loose screw remains at  least as    
audible as before exhaustion40 ,dr4     
,wollaston supposes that  this excessive
 tension of the drum of the ear1 when   
produced by the  compressed air in the  
diving-bell1 will also produce a        
corresponding  deafness to low tones4   
,this curious experiment has been since 
made  by ,dr4 ,colladon1 when descending
 in the diving-bell at ,howth1 in #ahbj4
  8,we descended10 says he1 8so slowly  
that we did not notice the motion  of   
the bell2 but as soon as the bell was   
immersed in water1 we felt  about the   
ears and the forehead a sense of        

pressure1 which continued  increasing   
during some minutes4 ,i did not1        
however1 experience any pain  in the    
ears2 but my companion suffered so much 
that we were obliged  to stop our       
descent for a short time4 ,to remedy    
that inconvenience1  the workmen        
instructed us1 after having closed our  
nostrils and mouth1  to endeavour to    
swallow1 and to restrain our respiration
 for some  moments1 in order that1 by   
this exertion1 the internal air might   
act  on the ,eustachian tube4 ,my       
companion1 however1 having tried it1    
found  himself very little relieved by  
this remedy4 ,after some minutes1 we    
resumed our descent4 ,my friend suffered
 considerably2 he was pale2 his  lips   
were totally discoloured2 his appearance
 was that of a man on the  point of     
fainting2 he was in involuntary low     
spirits1 owing1 perhaps1  to the        
violence of the pain1 added to that kind
 of apprehension which  our situation   
unavoidably inspired4 ,this appeared to 

me the more  remarkable1 as my case was 
totally the reverse4 ,i was in a state  
of  excitement resembling the effect of 
some spirituous liquor4 ,i suffered  no 
pain2 ,i experienced only a strong      
pressure round my head1 as if an  iron  
circle had been bound about it4 ,i spoke
 with the workmen1 and had  some        
difficulty in hearing them4 ,this       
difficulty of hearing rose to  such a   
height1 that during three or four       
minutes ,i could not hear them  speak4  
,i could not1 indeed1 hear myself speak1
 though ,i spoke as loudly  as possible2
 nor did even the great noise caused by 
the violence of the  current against the
 sides of the bell reach my ears40      
,the effect thus described by ,dr4      
,colladon is different from that        
anticipated by ,dr4 ,wollaston4 ,he was 
not merely deaf to low tones1 but  to   
all sounds whatever2 and ,i have found1 
by repeated experiment1 that  my own    
ears become perfectly insensible even to
 the shrill tones of the  female voice1 

and of the voice of a child1 when the   
drum of the ear is  thrown into a state 
of tension by yawning4    ,with regard  
to sounds of high pitch at the other    
extremity of the  scale1 ,dr4 ,wollaston
 has met with persons1 whose hearing was
 in  other respects perfect1 who never  
heard the chirping of the ,gryllus      
campestris1 which commonly occurs in    
hedges during a summer's evening1  or   
that of the house-cricket1 or the squeak
 of the bat1 or the chirping  of the    
common house-sparrow4 ,the note of the  
bat is a full octave  higher than that  
of the sparrow2 and ,dr4 ,wollaston     
believes that the  note of some insects 
may reach one octave more1 as there are 
sounds  decidedly higher than that of a 
small pipe1 one-fourth of an inch in    
length1 which he conceives cannot be far
 from six octaves above the  middle ,e  
of the pianoforte4 8,the suddenness of  
the transition10 says  ,dr4 ,wollaston1 
8from perfect hearing to total want of  
perception1  occasions a degree of      

surprise1 which renders an experiment on
 this  subject with a series of small   
pipes among several persons rather      
amusing4 ,it is curious to observe the  
change of feeling manifested  by various
 individuals of the party1 in           
succession1 as the sounds  approach and 
pass the limits of their hearing4 ,those
 who enjoy a  temporary triumph are     
often compelled in their turn to        
acknowledge to  how short a distance    
their little superiority extends40 ,in  
concluding  his interesting paper on    
this subject1 ,dr4 ,wollaston           
conjectures that  animals1 like the     
grylli 7whose powers of hearing appear  
to commence  nearly where ours          
terminate71 may have the power of       
hearing still  sharper sounds which at  
present we do not know to exist1 and    
that there  may be other insects having 
nothing in common with us1 but who are  
endowed with a power of exciting1 and a 
sense of perceiving1 vibrations  which  
make no impression upon our organs1     

while their organs are  equally         
insensible to the slower vibrations to  
which we are accustomed4    ,with the   
view of studying the class of sounds    
inaudible to certain  ears1 we would    
recommend it to the young naturalist to 
examine the  sounds emitted by the      
insect tribe1 both in relation to their 
effect  upon the human ear1 and to the  
mechanism by which they are produced4   
,the ,cicad or locusts in ,north        
,america appear1 from the observations  
of ,dr4 ,hildreth1#bh to be furnished   
with a bagpipe on which they play  a    
variety of notes4 8,when any one        
passes10 says he1 8they make a great    
noise and screaming with their air      
bladder or bagpipes4 ,these bags are    
placed under1 and rather behind1 the    
wings in the axilla1 something in  the  
manner of using the bagpipes with the   
bags under the arms--,i could  compare  
them to nothing else2 and1 indeed1 ,i   
suspect the first inventor  of the      
instrument borrowed his ideas from some 

insect of this kind4  ,they play a      
variety of notes and sounds1 one of     
which nearly imitates  the scream of the
 tree toad40     #bh ,edinburgh ,journal
 of ,science1 ,no4 xvii41 p4 #aeh4      
,among the acoustic wonders of the      
natural world may be ranked the  vocal  
powers of the statue of ,memnon1 the son
 of ,aurora1 which modern  discoveries  
have withdrawn from among the fables of 
ancient ,egypt4  ,the history of this   
remarkable statue is involved in much   
obscurity4  ,although ,strabo affirms   
that it was overturned by an earthquake1
 yet as  ,egypt exhibits no traces of   
such a convulsion1 it has been generally
  believed that the statue was mutilated
 by ,cambyses4 ,ph4 ,casselius1  in his 
dissertation on vocal or speaking       
stones1 quotes the remark  of the       
scholiast in ,juvenal1 8that1 when      
mutilated by ,cambyses1 the  statue1    
which saluted both the sun and the king1
 afterwards saluted  only the sun40     
,philostratus1 in his life of ,apollo1  

informs us1 that  the statue looked to  
the east1 and that it spoke as soon as  
the rays  of the rising sun fell upon   
its mouth4 ,pausanias1 who saw the      
statue  in its dismantled state1 says1  
that it is a statue of the sun1 that    
the ,egyptians call it ,phamenophis1 and
 not ,memnon1 and that it emits  sounds 
every morning at sunrise1 which can be  
compared only to that of  the breaking  
of the string of the lyre4 ,strabo      
speaks only of a single  sound which he 
heard2 but ,juvenal1 who had probably   
heard it often  during his stay in      
,egypt1 describes it as if it emitted   
several sounds3        ,dimidio magic   
resonant ubi ,memnone chord4      ,where
 broken ,memnon sounds his magic        
strings4    ,the simple sounds which    
issued from the statue were1 in the     
progress  of time1 magnified into       
intelligible words1 and even into an    
oracle of  seven verses1 and this       
prodigy has been recorded in a ,greek   
inscription  on the left leg of the     

statue4 ,but though this new faculty of 
the  colossus was evidently the         
contrivance of the ,egyptian priests1   
yet we  are not entitled from this to   
call in question the simple and         
perfectly  credible fact that it emitted
 sounds4 ,this property1 indeed1 it     
seems  to possess at the present day2   
for we learn1#bi that an ,english       
traveller1 ,sir ,a4 ,smith1 accompanied 
with a numerous escort1 examined  the   
statue1 and that at six o'clock in the  
morning he heard very  distinctly the   
sounds which had been so celebrated in  
antiquity4 ,he  asserts that this sound 
does not proceed from the statue1 but   
from the  pedestal2 and he expresses his
 belief that it arises from the impulse 
of the air upon the stones of the       
pedestal1 which are arranged so as  to  
produce this surprising effect4 ,this   
singular description is1 to a  certain  
extent1 confirmed by the description of 
,strabo1 who says1 that  he was quite   
certain that he heard a sound which     

proceeded either from  the base1 or from
 the colossus1 or from some one of the  
assistants4 ,as  there were no ,egyptian
 priests in the escort of ,sir ,a4      
,smith1 we may  now safely reject this  
last1 and1 for many centuries1 the most 
probable  hypothesis4     #bi ,revue    
,encyclopdique1 #ahba1 tome ix41 p4     
#eib4    ,the explanation suggested by  
,sir ,a4 ,smith had been previously     
given in  a more specific form by ,m4   
,dussaulx1 the translator of ,juvenal4  
8,the  statue10 says he1 8being hollow1 
the heat of the sun heated the air      
which it contained1 and this air1       
issuing at some crevice1 produced the   
sounds of which the priests gave their  
own interpretation40    ,rejecting this 
explanation1 ,m4 ,langles1 in his       
dissertation on the  vocal statue of    
,memnon1 and ,m4 ,salverte1 in his work 
on the occult  sciences1 have ascribed  
the sounds entirely to ,egyptian        
priestcraft2  and have even gone so far 
as to describe the mechanism by which   

the statue not only emitted sounds1 but 
articulated distinctly the  intonations 
appropriate to the seven ,egyptian      
vowels1 and consecrated  to the seven   
planets4 ,m4 ,langles conceives that the
 sounds may be  produced by a series of 
hammers1 which strike either the granite
  itself1 or sonorous stones like those 
which have been long used in  ,china for
 musical instruments4 ,m4 ,salverte     
improves this imperfect  apparatus1 by  
supposing that there might be adapted to
 these hammers a  clepsydra1 or         
water-clock1 or any other instrument    
fitted to measure  time1 and so         
constructed as to put the hammers in    
motion at sunrise4  ,not satisfied with 
this supposition1 he conjectures that   
the spring of  all this mechanism was to
 be found in the art of concentrating   
the rays  of the sun1 which was well    
known to the ancients4 ,between the lips
 of  the statue1 or in some less        
remarkable part of it concealed from    
view  by its height1 he conceives an    

aperture to be perforated1 containing a 
lens or a mirror capable of condensing  
the rays of the rising sun upon  one or 
more metallic levers1 which by their    
expansion put in motion  the seven      
hammers in succession4 ,hence he        
explains why the sounds were  emitted   
only at sunrise1 and when the solar rays
 fell upon the mouth of  the statue1 and
 why they were never again heard till   
the sun returned  to the eastern        
horizon4 ,as a piece of mechanism1 this 
contrivance is  defective in not        
providing for the change in the sun's   
amplitude1  which is very considerable  
even in ,egypt1 for as the statue and   
the  lens are both fixed1 and as the    
sounds were heard at all seasons of  the
 year1 the same lens which threw the    
,midsummer rays of the sun upon  the    
hammers could not possibly throw upon   
them his rays in winter4 ,but  even if  
the machinery were perfect1 it is       
obvious that it could not  have survived
 the mutilation of the statue1 and could

 not1 short of a  miracle1 have         
performed its part in the time of ,sir  
,a4 ,smith4    ,if we abandon the idea  
of the whole being a trick of the       
priesthood1  which has been generally   
done1 and which the recent observations 
of  ,sir ,a4 ,smith authorise us to do1 
we must seek some natural cause for  the
 phenomena similar to that suggested by 
,dussaulx4 ,it is curious  to observe   
how the study of nature gradually       
dispels the consecrated  delusions of   
ages1 and reduces to the level of       
ordinary facts what time  had invested  
with all the characters of the          
supernatural3 and in the  present case  
it is no less remarkable that the       
problem of the statue of  ,memnon should
 have been first solved by means of an  
observation made  by a solitary         
traveller wandering on the banks of the 
,orinoco4 8,the  granitic rock10 says   
,baron ,humboldt1 8on which we lay1 is  
one of those  where travellers on the   
,orinoco have heard from time to time1  

towards  sunrise1 subterraneous sounds  
resembling those of the organ4 ,the     
missionaries call these stones loxas de 
musica4 #8,it is witchcraft1'  said our 
young ,indian pilot4 ,we never ourselves
 heard these mysterious  sounds either  
at ,carichana ,vieja or in the upper    
,orinoco3 but from  information given us
 by witnesses worthy of belief1 the     
existence of a  phenomenon that seems to
 depend on a certain state of the       
atmosphere  cannot be denied4 ,the      
shelves of rock are full of very narrow 
and  deep crevices4 ,they are heated    
during the day to about #ej4 ,i often   
found their temperature at the surface  
during the night at #ci1 the            
surrounding atmosphere being at #bh4 ,it
 may easily be conceived that  the      
difference of temperature between the   
subterraneous and the  external air     
attains its maximum about sunrise1 or at
 that moment which  is at the same time 
farther from the period of the maximum  
of the heat  of the preceding day4 ,may 

not these sounds of an organ1 then1     
which are  heard when a person sleeps   
upon the rock1 his ear in contact with  
the  stone1 be the effect of a current  
of air that issues out through the      
crevices8 ,does not the impulse of the  
air against the elastic spangles  of    
mica that intercept the crevices        
contribute to modify the sounds8  ,may  
we not admit that the ancient           
inhabitants of ,egypt1 in passing       
incessantly up and down the ,nile1 had  
made the same observation on some  rock 
of the ,thebaid1 and that the music of  
the rocks there led to the  jugglery of 
the priests in the statue of ,memnon80  
,this curious case of the production of 
sounds in granite rocks at  sunrise     
might have been regarded as a           
transatlantic wonder which was  not     
applicable to ,egypt2 but by a singular 
coincidence of observation1  ,messrs4   
,jomard1 ,jollois1 and ,devilliers1 who 
were travelling in ,egypt  nearly about 
the same time that ,m4 ,humboldt was    

traversing the wilds of  ,south         
,america1 heard1 at sunrise1 in a       
monument of granite1 situated  near the 
centre of the spot on which the palace  
of ,carnac stands1 a  noise resembling  
that of a breaking string1 the very     
expression by  which ,pausanias         
characterizes the sound in the          
,memnonian granite4 ,the  travellers    
regarded these sounds as arising from   
the transmission  of rarefied air       
through the crevices of a sonorous      
stone1 and they  were of the same       
opinion with ,humboldt1 that these      
sounds might have  suggested to the     
,egyptian priests the juggleries of the 
,memnonium4  ,is it not strange that the
 ,prussian and the ,french travellers   
should  not have gone a step farther1   
and solved the problem of two thousand  
years1 by maintaining that the sound of 
the statue of ,memnon was itself  a     
natural phenomenon1 or a granitic sound 
elicited at sunrise by the  very same   
causes which operated on the ,orinoco   

and in the temple of  ,carnac1 in place 
of regarding it as a trick in imitation 
of natural  sounds8 ,if1 as ,humboldt   
supposes1 the ancient inhabitants of    
,egypt  had1 in passing incessantly up  
and down the ,nile1 become familiar with
  the music of the granite rocks of the 
,thebaid1 how could the imitation  of   
such natural and familiar sounds be     
regarded by the priests as a  means of  
deceiving the people8 ,there could be   
nothing marvellous in  a colossal statue
 of granite giving out the very same    
sounds that  were given out at the same 
time of the day by a granite rock2 and  
in  place of reckoning it a supernatural
 fact1 they could regard it in no  other
 light than as the duplicate of a       
well-known natural phenomenon4  ,it is a
 mere conjecture1 however1 that such    
sounds were common in the  ,thebaid2 and
 it is therefore probable that a granite
 rock1 possessing  the property of      
emitting sounds at sunrise1 had been    
discovered by the  priests1 who were at 

the same time the philosophers of       
,egypt1 and that  the block had been    
employed in the formation of the        
,memnonian statue  for the purpose of   
impressing upon it a supernatural       
character1 and  enabling them to        
maintain their influence over a         
credulous people4    ,the inquiries of  
recent travellers have enabled us to    
corroborate  these views1 and to add    
another remarkable example of the       
influence of  subterraneous sounds over 
superstitious minds4 ,about three       
leagues to  the north of ,tor in ,arabia
 ,petra1 is a mountain1 within the bosom
 of  which the most singular sounds have
 been heard4 ,the ,arabs of the ,desert 
ascribe these sounds to a convent of    
monks preserved miraculously            
underground2 and the sound is supposed  
to be that of the ,nakous1 a  long      
narrow metallic ruler suspended         
horizontally1 which the priest  strikes 
with a hammer for the purpose of        
assembling the monks to  prayer4 ,a     

,greek was said to have seen the        
mountain open1 and to have  descended   
into the subterranean convent1 where he 
found fine gardens  and delicious water2
 and1 in order to give proof of his     
descent1 he  produced some fragments of 
consecrated bread1 which he pretended to
  have brought from the subterranean    
convent4 ,the inhabitants of ,tor       
likewise declare that the camels are not
 only frightened1 but rendered  furious1
 when they hear these subterraneous     
sounds4    ,m4 ,seetzen1 the first      
,european traveller who visited this    
extraordinary  mountain1 set out from   
,wodyel ,nackel on the #agth of ,june1  
at five  o'clock in the morning4 ,he was
 accompanied by a ,greek ,christian and 
some ,bedouin ,arabs1 and after a       
quarter of an hour's walk they reached  
the foot of a majestic rock of hard     
sand-stone4 ,the mountain itself was    
quite bare and entirely composed of it4 
,he found inscribed upon the  rock      
several ,greek and ,arab names1 and also

 some ,koptic characters1  which proved 
that it had been resorted to for        
centuries4 ,about noon the  party       
reached the foot of the mountains called
 ,nakous1 where at the  foot of a ridge 
they beheld an insulated peaked rock4   
,this mountain  presented upon two of   
its sides two sandy declivities about   
#aej feet  high1 and so inclined that   
the white and slightly adhering sand    
which  rests upon its surface is        
scarcely able to support itself2 and    
when the  scorching heat of the sun     
destroys its feeble cohesion1 or when it
 is  agitated by the smallest motions1  
it slides down the two declivities4     
,these declivities unite behind the     
insulated rock1 forming an acute  angle1
 and like the adjacent surfaces1 they   
are covered with steep  rocks which     
consist chiefly of a white and friable  
free-stone4    ,the first sound which   
greeted the ears of the travellers took 
place  at an hour and a quarter after   
noon4 ,they had climbed with great      

difficulty as far as the sandy          
declivity1 a height of seventy or       
eighty feet1 and had rested beneath the 
rocks where the pilgrims are  accustomed
 to listen to the sounds4    ,while in  
the act of climbing1 ,m4 ,seetzen heard 
the sound from beneath  his knees1 and  
hence he was led to think that the      
sliding of the sand  was the cause of   
the sound1 and not the effect of the    
vibration which  it occasioned4 ,at     
three o'clock the sound became louder   
and continued  six minutes1 and after   
having ceased for ten minutes1 it was   
again  heard4 ,the sound appeared to    
have the greatest resemblance to that   
of the humming-top1 rising and falling  
like that of an olian harp4  ,believing 
that he had discovered the true origin  
of the sound1 ,m4  ,seetzen was anxious 
to repeat the experiment1 and with this 
view he  climbed with the utmost        
difficulty to the highest rocks1 and    
sliding  down as fast as he could1 he   
endeavoured1 with the help of his hands 

and feet1 to set the sand in motion4    
,the effect thus produced far  exceeded 
his expectations1 and the sand in       
rolling beneath him made so  loud a     
noise1 that the earth seemed to tremble 
to such a degree that he  states he     
should certainly have been afraid if he 
had been ignorant of  the cause4    ,m4 
,seetzen throws out some conjectures    
respecting the cause of  these sounds4  
,does the rolling layer of sand1 says   
he1 act like the  fiddle-bow1 which1 on 
being rubbed upon a plate of glass1     
raises  and distributes into regular    
figures the sand with which the plate   
is covered8 ,does the adherent and fixed
 layer of sand perform here  the part of
 the plate of glass1 and the            
neighbouring rocks that of  the sounding
 body8 ,we cannot pretend to answer     
these questions1  but we trust that some
 philosopher competent to the task will 
have  an opportunity of examining these 
interesting phenomena with more         
attention1 and describing them with     

greater accuracy4    ,the only person1  
so far as ,i can learn1 who has visited 
,el-,nakous1  since the time of         
,seetzen1 is ,mr4 ,gray1 of ,university 
,college1  ,oxford2 but he has not added
 much to the information acquired by his
  predecessor4 ,during the first visit  
which he made to the place1 he  heard at
 the end of a quarter of an hour a low  
continuous murmuring  sound beneath his 
feet1 which gradually changed into      
pulsations as  it became louder1 so as  
to resemble the striking of a clock1 and
 at  the end of five minutes it became  
so strong as to detach the sand4        
,returning to the spot next day1 he     
heard the sound still louder than       
before4 ,he could not observe any       
crevices by which the external air      
could penetrate2 and as the sky was     
serene and the air calm1 he was         
satisfied that the sounds could not     
arise from this cause4#cj     #cj ,see  
,edinburgh ,journal of ,science1 ,no4   
xi41 p4 #aec1 and ,no4   xiii41 p4 #ea4 

,,letter ,x4     ,mechanical inventions 
of the ancients few in number--,ancient 
and modern feats of strength--,feats of 
,eckeberg particularly                  
described--,general explanation of      
them--,real feats of strength           
performed by ,thomas                    
,topham--,remarkable power of lifting   
heavy   persons when the lungs are      
inflated--,belzoni's feat of sustaining 
pyramids of men--,deception of walking  
along the ceiling in an   inverted      
position--,pneumatic apparatus in the   
foot of the house-fly   for enabling it 
to walk in opposition to                
gravity--,description of   the analogous
 apparatus employed by the gecko lizard 
for the same   purpose--,apparatus used 
by the ,echineis remora1 or             
sucking-fish4      ,the mechanical      
knowledge of the ancients was           
principally theoretical1  and though    
they seem to have constructed some minor
 pieces of mechanism  which were        
sufficient to delude the ignorant1 yet  

there is no reason  for believing that  
they had executed any machinery that was
 capable  of exciting much surprise1    
either by its ingenuity or its          
magnitude4  ,the properties of the      
mechanical powers1 however1 seem to have
 been  successfully employed in         
performing feats of strength which were 
beyond  the reach even of strong men1   
and which could not fail to excite the  
greatest wonder when exhibited by       
persons of ordinary size4    ,firmus1 a 
native of ,seleucia1 who was executed by
 the ,emperor ,aurelian  for espousing  
the cause of ,zenobia1 was celebrated   
for his feats of  strength4 ,in his     
account of the life of ,firmus1 who     
lived in the third  century1 ,vopiscus  
informs us1 that he could suffer iron to
 be forged  upon an anvil placed upon   
his breast4 ,in doing this he lay upon  
his  back1 and resting his feet and     
shoulders against some support1 his     
whole body formed an arch1 as we shall  
afterwards more particularly  explain4  

,until the end of the sixteenth century1
 the exhibition of  such feats does not 
seem to have been common4 ,about the    
year #agjc1 a  native of ,kent1 of the  
name of ,joyce1 exhibited such feats of 
strength  in ,london and other parts of 
,england1 that he received the name of  
the  second ,samson4 ,his own personal  
strength was very great2 but he had     
also discovered1 without the aid of     
theory1 various positions of his  body  
in which men even of common strength    
could perform very surprising  feats4   
,he drew against horses1 and raised     
enormous weights2 but as  he actually   
exhibited his power in ways which       
evinced the enormous  strength of his   
own muscles1 all his feats were ascribed
 to the same  cause4 ,in the course of  
eight or ten years1 however1 his methods
  were discovered1 and many individuals 
of ordinary strength exhibited  a number
 of his principal performances1 though  
in a manner greatly  inferior to ,joyce4
    ,some time afterwards1 ,john        

,charles ,van ,eckeberg1 a native of    
,harzgerode1 in ,anhalt1 travelled      
through ,europe under the appellation   
of ,samson1 exhibiting very remarkable  
examples of his strength4  ,this1 we    
believe1 is the same person whose feats 
are particularly  described by ,dr4     
,desaguliers4 ,he was a man of the      
middle size1 and  of ordinary strength2 
and as ,dr4 ,desaguliers was convinced  
that his  feats were exhibitions of     
skill and not of strength1 he was       
desirous  of discovering his methods1   
and with this view he went to see him1  
accompanied by the ,marquis of          
,tullibardine1 ,dr4 ,alexander ,stuart1 
and  ,dr4 ,pringle1 and his own         
mechanical operator4 ,they placed       
themselves  round the ,german1 so as to 
be able to observe accurately all that  
he  did1 and their success was so great 
that they were able to perform most  of 
the feats the same evening by           
themselves1 and almost all the rest     
when they had provided the proper       

apparatus4 ,dr4 ,desaguliers exhibited  
some of the experiments before the      
,royal ,society1 and has given such a   
distinct explanation of the principles  
on which they depend1 that we  shall    
endeavour to give a popular account of  
them4    ,illustration3 ,fig4 #eb4      
#a4 ,the performer sat upon an inclined 
board ,a ,b1 placed upon a frame  ,c ,d 
,e1 with his feet abutting against the  
upright board ,c4 ,round his  loins was 
placed a strong girdle ,f ,g1 to the    
iron ring of which at ,g  was fastened a
 rope by means of a hook4 ,the rope     
passed between his  legs through a hole 
in the board ,c1 and several men or two 
horses1  pulling at the other end of the
 rope1 were unable to draw the          
performer out of his place4 ,his hands  
at ,g seemed to pull against the  men1  
but they were of no advantage to him    
whatever4    ,illustration3 ,fig4 #ec4  
#b4 ,another of the ,german's feats is  
shown in ,fig4 #ec4 ,having fixed the   
rope above-mentioned to a strong post at

 ,a1 and made it pass through  a fixed  
iron eye at ,b1 to the ring in his      
girdle1 he planted his feet  against the
 post at ,b1 and raised himself from the
 ground by the rope1  as shown in the   
figure4 ,he then suddenly stretched out 
his legs1 and  broke the rope1 falling  
back on a feather-bed at ,c1 spread out 
to  receive him4    #c4 ,in imitation of
 ,firmus1 he laid himself down on the   
ground1 as shown  in ,fig4 #ed1 and when
 an anvil ,a was placed upon his breast1
 a man  hammered with all his force the 
piece of iron ,b1 with a sledge hammer2 
and sometimes two smiths cut in two with
 chisels a great cold bar of  iron laid 
upon the anvil4 ,at other times a stone 
of huge dimensions1  half of which is   
shown at ,c1 was laid upon his belly1   
and broken with a  blow of the great    
hammer4    ,illustration3 ,fig4 #ed4    
#d4 ,the performer then placed his      
shoulders upon one chair and his  heels 
upon another1 as in ,fig4 #ee1 forming1 
with his backbone1 thighs1  and legs1 an

 arch springing from its abutments at ,a
 and ,b4 ,one or two  men then stood    
upon his belly1 rising up and down while
 the performer  breathed4 ,a stone1 one 
and a half feet long1 one foot broad1   
and  half a foot thick1 was then laid   
upon his belly1 and broken by a         
sledge-hammer2 an operation which may be
 performed with much less  danger than  
when his back touched the ground1 as in 
,fig4 #ed4    ,illustration3 ,fig4 #ee4 
#e4 ,his next feat was to lie down on   
the ground1 as in ,fig4 #ef2 a man      
being then placed on his knees1 he draws
 his heels towards his body1  and1      
raising his knees1 he lifts up the man  
gradually1 till having  brought his     
knees perpendicularly under him1 as in  
,fig4 #eg1 he raises  his own body up1  
and placing his arms round the man's    
legs1 he rises  with him1 and sets him  
down on some low table or eminence of   
the same  height as his knees4 ,this    
feat he sometimes performed with two men
 in  place of one4    ,illustration3    

,fig4 #ef4    ,illustration3 ,fig4 #eg4 
#f4 ,the last and apparently the most   
wonderful performance of the ,german  is
 shown in ,fig4 #eh1 where he appears to
 raise a cannon ,a placed upon  a scale1
 the four ropes of the scale being fixed
 to a rope or chain  attached to his    
girdle in the manner already described4 
,previous to the  fixing of the ropes1  
the cannon and scale rest upon two      
rollers ,b1 ,c2  but when all is ready1 
the two rollers are knocked from beneath
 the  scale1 and the cannon is sustained
 by the strength of his loins4          
,illustration3 ,fig4 #eh4    ,the       
,german also exhibited his strength in  
twisting into a screw a flat  piece of  
iron like ,a1 ,fig4 #ei4 ,he first bent 
the iron into a right  angle as at ,b1  
and then wrapping his handkerchief about
 its broad upper  end1 he held that end 
in his left hand1 and with his right    
applied to  the other end1 twisted about
 the angular point1 as shown at ,c4     
,lord  ,tullibardine succeeded in doing 

the same thing1 and even untwisted one  
of the irons which the ,german had      
twisted4    ,illustration3 ,fig4 #ei4   
,it would lead into details by no means 
popular were ,i to give a minute        
explanation of the mechanical principles
 upon which these feats depend4  ,a few 
general observations will perhaps be    
sufficient for ordinary  readers4 ,the  
feats ,nos4 #a1 #b1 and #f1 depend      
entirely on the natural  strength of the
 bones of the pelvis1 which form a      
double arch1 which  it would require an 
immense force to break1 by any external 
pressure  directed to the centre of the 
arch2 and as the legs and thighs are    
capable of sustaining four or five      
thousand pounds when they stand  quite  
upright1 the performer has no difficulty
 in resisting the force  of two horses1 
or of sustaining the weight of a cannon 
weighing two or  three thousand pounds4 
,the feat of the anvil is certainly a   
very surprising one4 ,the  difficulty1  
however1 really consists in sustaining  

the anvil1 for when  this is done1 the  
effect of the hammering is nothing4 ,if 
the anvil  were a thin piece of iron1 or
 even two or three times heavier than   
the  hammer1 the performer would be     
killed by a few blows2 but the blows    
are scarcely felt when the anvil is very
 heavy1 for the more matter  the anvil  
has1 the greater is its inertia1 and it 
is the less liable  to be struck out of 
its place2 for when it has received by  
the blow  the whole momentum of the     
hammer1 its velocity will be so much    
less  than that of the hammer1 as its   
quantity of matter is greater4 ,when the
  blow1 indeed1 is struck1 the man feels
 less of the weight of the anvil  than  
he did before1 because in the reaction  
of the stone all the parts  of it round 
about the hammer rise towards the blow4 
,this property is  illustrated by the   
well-known experiment of laying a stick 
with its  ends upon two drinking-glasses
 full of water1 and striking the stick  
downwards in the middle with an iron    

bar4 ,the stick will in this case  be   
broken without breaking the glasses or  
spilling the water4 ,but if  the stick  
is struck upwards1 as if to throw it up 
in the air1 the  glasses will break if  
the blow be strong1 and if the blow is  
not very  quick1 the water will be spilt
 without breaking the glasses4    ,when 
the performer supports a man upon his   
belly as in ,fig4 #ee1 he does  it by   
means of the strong arch formed by his  
backbone1 and the bones of  his legs and
 thighs4 ,if there were room for them1  
he could bear three  or four1 or1 in    
their stead1 a great stone to be broken 
with one blow4    ,a number of feats of 
real and extraordinary strength were    
exhibited1  about a century ago1 in     
,london1 by ,thomas ,topham1 who was    
five feet  ten inches high1 and about   
thirty-one years of age4 ,he was        
entirely  ignorant of any of the methods
 for making his strength appear more    
surprising1 and he often performed by   
his own natural powers what he  learned 

had been done by others by artificial   
means4 ,a distressing  example of this  
occurred in his attempt to imitate the  
feat of the  ,german ,samson1 by pulling
 against horses4 ,ignorant of the method
 which  we have already described1 he   
seated himself on the ground with his   
feet against two stirrups1 and by the   
weight of his body he succeeded  in     
pulling against a single horse2 but in  
attempting to pull against  two horses1 
he was lifted out of his place1 and one 
of his knees was  shattered against the 
stirrups1 so as to deprive him of most  
of the  strength of one of his legs4    
,the following are the feats of real    
strength which ,dr4 ,desaguliers saw him
 perform3--    #a4 ,having rubbed his   
fingers with coal-ashes to keep them    
from  slipping1 he rolled up a very     
strong and large pewter plate4    #b4   
,having laid seven or eight short and   
strong pieces of tobacco-pipe  on the   
first and third finger1 he broke them by
 the force of his middle  finger4    #c4

 ,he broke the bowl of a strong         
tobacco-pipe placed between his first   
and third finger1 by pressing his       
fingers together sideways4    #d4       
,having thrust such another bowl under  
his garter1 his legs being  bent1 he    
broke it to pieces by the tendons of his
 hams without altering  the bending of  
his leg4    #e4 ,he lifted with his     
teeth1 and held in a horizontal position
 for a  considerable time1 a table six  
feet long1 with half a hundred weight   
hanging at the end of it4 ,the feet of  
the table rested against his  knees4    
#f4 ,holding in his right hand an iron  
kitchen poker three feet long and  three
 inches round1 he struck upon his bare  
left arm1 between the elbow  and the    
wrist1 till he bent the poker nearly to 
a right angle4    #g4 ,taking a similar 
poker and holding the ends of it in his 
hands1 and  the middle against the back 
of his neck1 he brought both ends of it 
together before him1 and he then pulled 
it almost straight again4 ,this  last   

feat was the most difficult1 because the
 muscles which separate  the arms       
horizontally from each other are not so 
strong as those which  bring them       
together4    #h4 ,he broke a rope about 
two inches in circumference1 which was  
partly  wound about a cylinder four     
inches in diameter1 having fastened the 
other end of it to straps that went over
 his shoulder4    #i4 ,dr4 ,desaguliers 
saw him lift a rolling-stone of about   
#hjjlb4 weight  with his hands only1    
standing in a frame above it1 and taking
 hold  of a frame fastened to it4 ,hence
 ,dr4 ,desaguliers gives the following  
relative view of the strengths of       
individuals3--      ,strength of the    
weakest men   #abelbs4    ,strength of  
very strong men   #djj    ,strength of  
,topham            #hjj    ,the weight  
of ,topham was about #bjj4    ,one of   
the most remarkable and inexplicable    
experiments relative to the  strength of
 the human frame1 which you have        
yourself seen and admired1  is that in  

which a heavy man is raised with the    
greatest facility1 when  he is lifted up
 the instant that his own lungs and     
those of the persons  who raise him are 
inflated with air4 ,this experiment was1
 ,i believe1  first shown in ,england a 
few years ago by ,major ,h4 who saw it  
performed  in a large party at ,venice1 
under the direction of an officer of the
  ,american ,navy4 ,as ,major ,h4       
performed it more than once in my       
presence1  ,i shall describe as nearly  
as possible the method which he         
prescribed4  ,the heaviest person in the
 party lies down upon two chairs1 his   
legs  being supported by the one and his
 back by the other4 ,four persons1  one 
at each leg and one at each shoulder1   
then try to raise him1 and  they find   
his dead weight to be very great1 from  
the difficulty they  experience in      
supporting him4 ,when he is replaced in 
the chair1 each  of the four persons    
takes hold of the body as before1 and   
the person  to be lifted gives two      

signals by clapping his hands4 ,at the  
first  signal he himself and the four   
lifters begin to draw a long and full   
breath1 and when the inhalation is      
completed1 or the lungs filled1  the    
second signal is given for raising the  
person from the chair4 ,to  his own     
surprise and that of his bearers1 he    
rises with the greatest  facility1 as if
 he were no heavier than a feather4 ,on 
several occasions  ,i have observed that
 when one of the bearers performs his   
part ill1  by making the inhalation out 
of time1 the part of the body which he  
tries to raise is left as it were       
behind4 ,as you have repeatedly seen    
this experiment1 and have performed the 
part both of the load and of  the       
bearer1 you can testify how remarkable  
the effects appear to all  parties1 and 
how complete is the conviction1 either  
that the load has  been lightened1 or   
the bearer strengthened by the          
prescribed process4    ,at ,venice1 the 
experiment was performed in a much more 

imposing  manner4 ,the heaviest man in  
the party was raised and sustained upon 
the points of the fore-fingers of six   
persons4 ,major ,h4 declared that  the  
experiment would not succeed if the     
person lifted were placed upon  a board1
 and the strength of the individuals    
applied to the board4 ,he  conceived it 
necessary that the bearers should       
communicate directly  with the body to  
be raised4 ,i have not had an           
opportunity of making any  experiments  
relative to these curious facts2 but    
whether the general  effect is an       
illusion1 or the result of known or of  
new principles1 the  subject merits a   
careful investigation4    ,among the    
remarkable exhibitions of mechanical    
strength and dexterity1  we may         
enumerate that of supporting pyramids of
 men4 ,this exhibition  is a very       
ancient one4 ,it is described1 though   
not very clearly1 by  the ,roman poet   
,claudian1 and it has derived some      
importance in modern  times1 in         

consequence of its having been performed
 in various parts of  ,great ,britain by
 the celebrated traveller ,belzoni1     
before he entered  upon the more        
estimable career of an explorer of      
,egyptian antiquities4  ,the simplest   
form of this feat consists in placing a 
number of men on  each other's          
shoulders1 so that each row consists of 
a man fewer till  they form a pyramid   
terminating in a single person1 upon    
whose head a  boy is sometimes placed   
with his feet upwards4    ,among the    
displays of mechanical dexterity1 though
 not grounded on any  scientific        
principle1 may be mentioned the art of  
walking along the  ceiling of an        
apartment with the head downwards4 ,this
 exhibition1  which we have witnessed in
 one of the ,london ,theatres1 never    
failed  to excite the wonder of the     
audience1 although the movements of the 
inverted performer were not such as to  
inspire us with any high  ideas of the  
mechanism by which they were effected4  

,the following  was probably the method 
by which the performer was carried along
 the  ceiling4 ,two parallel grooves or 
openings were made in the ceiling at    
the same distance as the foot-tracks of 
a person walking on sand4 ,these        
grooves were narrower than the human    
foot1 so as to permit a rope1  or chain1
 or strong wire1 attached to the feet of
 the performer1 to  pass through the    
ceiling1 where they were held by two or 
more persons  above it4 ,in this way the
 inverted performer might be carried    
along  by a sliding or shuffling motion1
 similar to that which is adopted in    
walking in the dark1 and in which the   
feet are lifted from the ground4  ,a    
more regular motion1 however1 might be  
produced by a contrivance for  attaching
 the rope or chain to the sole of the   
foot1 at each step1 and  subsequently   
detaching it4 ,in this way1 when the    
performer is pulled  against the ceiling
 by his left foot1 he would lift his    
right foot1  and having made a step with

 it1 and planted it against the grooves1
  the rope would be attached to it1 and 
when the rope was detached from  the    
left foot1 it would make a similar step1
 while the right foot was  pulled       
against the ceiling4 ,these effects     
might be facilitated and  rendered more 
natural1 by attaching to the body or to 
the feet of  the performer strong wires 
invisible to the audience1 and by using 
friction-wheels1 if a sliding motion    
only is required4    ,illustration3     
,fig4 #fj4    ,a more scientific method 
of walking upon the ceiling is suggested
 by  those beautiful pneumatic          
contrivances by which insects1 fishes1  
and  even some lizards are enabled to   
support the weight of their bodies      
against the force of gravity4 ,the      
house-fly is well known to have the     
power of walking in an inverted position
 upon the ceilings of rooms1  as well as
 upon the smoothest surfaces4 ,in this  
case the fly does not  rest upon its    
legs1 and must therefore adhere to the  

ceiling1 either by  some glutinous      
matter upon its feet1 or by the aid of  
some apparatus  given it for that       
purpose4 ,in examining the foot of the  
fly with a  powerful microscope1 it is  
found to consist of two concavities1 as 
shown in ,figs4 #fj and #fa1 the first  
of which is copied from a drawing  by   
,g4 ,adams1 published in #agdf1 and the 
second by ,j4 ,c4 ,keller1 a  painter at
 ,nuremberg1 who drew it for a work     
published in #agff4 ,the  author of this
 work maintains that these concavities  
are only used when  the fly moves       
horizontally1 and that1 when it moves   
perpendicularly or  on the ceiling1 they
 are turned up out of the way1 and the  
progressive  motion is effected by      
fixing the claws shown in the figure    
into the  irregularities of the surface 
upon which the fly moves1 whether it is 
glass1 porcelain1 or any other          
substance4 ,sir ,everard ,home1 however1
  supposes1 with great reason1 that     
these concave surfaces are 7like  the   

leathern suckers used by children for   
lifting stones7 employed to  form a     
vacuum1 so that the foot adheres1 as it 
were1 by suction to  the ceiling1 and   
enables the insect to support itself in 
an inverted  position4    ,illustration3
 ,fig4 #fa4    ,this conclusion ,sir    
,everard has been led to draw from an   
examination  of the foot of the ,lacerta
 ,gecko4 ,sir ,joseph ,banks had        
mentioned to him  in the year #ahae1    
that this lizard1 which is a native of  
the island of  ,java1 comes out in the  
evening from the roofs of the houses1   
and walks  down the smooth hard-polished
 chunam walls in search of the flies    
which  settle upon them1 and which are  
its natural food4 ,when ,sir ,joseph was
  at ,batavia1 he amused himself in     
catching this lizard4 ,he stood close   
to the wall at some distance from the   
animal1 and by suddenly scraping  the   
wall with a long flattened pole1 he was 
able to bring the animal to  the ground4
    ,having procured from ,sir ,joseph a

 very large specimen of the ,gecko1     
which weighed #e ounces avoirdupois1    
,sir ,everard ,home was enabled  to     
ascertain the peculiar mechanism by     
which the feet of this animal  have the 
power of keeping hold of a smooth hard  
perpendicular wall1 and  carry up so    
heavy a weight as that of its body4     
,illustration3 ,fig4 #fb4               
,illustration3 ,fig4 #fc4    ,the foot  
of the ,gecko has five toes 7as shown in
 ,fig4 #fb71 and at  the end of each of 
them1 except the thumb1 is a very sharp 
and  highly-curved claw4 ,on the under  
surface of each toe are sixteen         
transverse slits1 leading to as many    
cavities or pockets1 the depth of  which
 is nearly equal to the length of the   
slit that forms the surface4            
,illustration3 ,fig4 #fd4    ,this      
structure is shown in ,figs4 #fc and    
#fd1 the former representing the  under 
surface of one of the toes of the       
natural size1 and the latter  a toe     
dissected and highly magnified1 to show 

the appearance of the  cavities in its  
under surface1 their fringed edge1 the  
depth of the  cavities1 and the small   
muscles by which they are drawn open4   
,the edge  of the pockets or cavities is
 composed of rows of a beautiful fringe 
which are applied to the surface on     
which the animal walks against  gravity1
 while the pockets themselves are pulled
 up by the muscles  attached to them1 so
 as to form the cavities into suckers4  
,this structure ,sir ,everard ,home     
found to bear a considerable            
resemblance to that portion of the head 
of the ,echineis ,remora1 or            
sucking-fish1 by which it attaches      
itself to the shark1 or the bottoms  of 
ships4 ,this apparatus is shown in ,fig4
 #fe3 it is an oval form1 and  is       
surrounded by a broad loose moveable    
edge1 capable of applying  itself       
closely to the surface on which it is   
set4 ,it consists of two  rows of       
cartilaginous plates connected by one   
edge to the surface on  which they are  

placed1 the other1 on the external edge1
 being serrated  like that in the       
cavities of the feet of the ,gecko4 ,the
 two rows are  separated by a thin      
ligamentous partition1 and the plates1  
being raised  or depressed by the       
voluntary muscles1 form so many vacua1  
by means of  which the adhesion of the  
fish is effected4    ,illustration3     
,fig4 #fe4    ,these beautiful          
contrivances of ,divine ,wisdom cannot  
fail to arrest the  attention and excite
 the admiration of the reader2 but      
though there  can be little doubt that  
they are pneumatic suckers wrought by   
the  voluntary muscles of the animals to
 which they belong1 yet we would        
recommend the further examination of    
them to the attention of those who  have
 good microscopes at their command4     
,,letter ,,xi4     ,mechanical automata 
of the ancients--,moving                
tripods--,automata   of ,ddalus--,wooden
 pigeon of ,archytas--,automatic clock  
of   ,charlemagne--,automata made by    

,turrianus for ,charles ,v4--,camus's   
automatic carriage made for ,louis      
,,xiv4--,degenne's mechanical           
peacock--,vaucanson's duck which ate and
 digested its food--,du   ,moulin's     
automata--,baron ,kempelen's automaton  
chess-player--,drawing   and writing    
automata--,maillardet's                 
conjurer--,benefits derived from   the  
passion for automata--,examples of      
wonderful machinery for useful          
purposes--,duncan's tambouring          
machinery--,watt's statue-turning       
machinery--,babbage's calculating       
machinery4      ,we have already seen   
that the ancients had attained some     
degree of  perfection in the            
construction of automata1 or pieces of  
mechanism  which imitated the movements 
of man and the lower animals4 ,the      
tripods1  which ,homer#ca mentions as   
having been constructed by ,vulcan for  
the  banqueting-hall of the gods1       
advanced of their own accord to the     
table1  and again returned to their     

place4 ,self-moving tripods are         
mentioned by  ,aristotle2 and           
,philostratus informs us1 in his life of
 ,apollonius1 that  this philosopher saw
 and admired similar pieces of mechanism
 among the  sages of ,india4     #ca    
,iliad1 lib4 xviii41 #cgc-cgh4          
,ddalus enjoys also the reputation of   
having constructed machines that        
imitated the motions of the human body4 
,some of his statues are said  to have  
moved about spontaneously2 and ,plato1  
,aristotle1 and others  have related    
that it was necessary to tie them1 in   
order to prevent  them from running     
away4 ,aristotle speaks of a wooden     
,venus1 which moved  about in           
consequence of quicksilver being poured 
into its interior2 but  ,callistratus1  
the tutor of ,demosthenes1 states1 with 
some probability1  that the statues of  
,ddalus received their motion from the  
mechanical  powers4 ,beckmann is of     
opinion that the statues of ,ddalus     
differed  only from those of the early  

,greeks and ,egyptians in having their  
eyes  open and their feet and hands     
free1 and that the reclining posture of 
some1 and the attitude of others1 8as if
 ready to walk10 gave rise to  the      
exaggeration that they possessed the    
power of locomotion4 ,this  opinion1    
however1 cannot be maintained with any  
show of reason2 for if  we apply such a 
principle in one case1 we must apply it 
in all1 and  the mind would be left in a
 state of utter scepticism respecting   
the  inventions of ancient times4    ,we
 are informed by ,aulus ,gellius1 on the
 authority of ,favorinus1  that         
,archytas of ,tarentum1 who flourished  
about four hundred years  before        
,christ1 constructed a wooden pigeon    
that was capable of flying4  ,favorinus 
relates that1 when it had once alighted1
 it could not again  resume its flight2 
and ,aulus ,gellius adds1 that it was   
suspended by  balancing1 and animated by
 a concealed aura1 or spirit4    ,among 
the earliest pieces of modern mechanism 

was the curious  water-clock presented  
to ,charlemagne by the ,kaliph ,haroun  
al ,raschid4  ,in the dial-plate there  
were twelve small windows corresponding 
with  the divisions of the hours4 ,the  
hours were indicated by the opening of  
the windows1 which let out little       
metallic balls1 which struck the hour   
by falling upon a brazen bell4 ,the     
doors continued open till twelve        
o'clock1 when twelve little knights1    
mounted on horseback1 came out  at the  
same instant1 and after parading round  
the dial1 shut all the  windows and     
returned to their apartments4#cb     #cb
 ,annales ,loisiliani1 anno #hjg4       
,the next automata of which any distinct
 account has been preserved  are those  
of the celebrated ,john ,muller1        
,regiomontanus1 which have  been        
mentioned by ,kircher1 ,baptista ,porta1
 ,gassendi1 ,lana1 and ,bishop          
,wilkins4 ,this philosopher is said to  
have constructed an artificial  eagle1  
which flew to meet the ,emperor         

,maximilian when he arrived at          
,nuremberg on the #gth ,june1 #agdj4    
,after soaring aloft in the air1 the    
eagle is stated to have met the ,emperor
 at some distance from the city1  and to
 have returned and perched upon the town
 gate1 where it waited  his approach4   
,when the ,emperor reached the gate1 the
 eagle stretched  out its wings1 and    
saluted him by an inclination of its    
body4 ,muller  is likewise reported to  
have constructed an iron fly which was  
put  in motion by wheel-work1 and which 
flew about and leapt upon the  table4   
,at an entertainment given by this      
philosopher to some of his  familiar    
friends1 the fly flew from his hand1 and
 after performing a  considerable round1
 it returned again to the hand of its   
master4    ,the ,emperor ,charles ,v41  
after his abdication of the throne1     
amused  himself in his later years with 
automata of various kinds4 ,the artist  
whom he employed was ,janellus          
,turrianus of ,cremona4 ,it was his     

custom  after dinner to introduce upon  
the table figures of armed men and      
horses4 ,some of these beat drums1      
others played upon flutes1 while a      
third set attacked each other with      
spears4 ,sometimes he let fly wooden    
sparrows1 which flew back again to their
 nest4 ,he also exhibited  corn-mills so
 extremely small that they could be     
concealed in a glove1  yet so powerful  
that they could grind in a day as much  
corn as would  supply eight men with    
food for a day4    ,the next piece of   
mechanism of sufficient interest to     
merit our  attention is that which was  
made by ,m4 ,camus1 for the amusement of
  ,louis ,,xiv4 when a child4 ,it       
consisted of a small coach1 which was   
drawn  by two horses1 and which         
contained the figure of a lady within1  
with a  footman and page behind4 ,when  
this machine was placed at the extremity
  of a table of the proper size1 the    
coachman smacked his whip1 and the      
horses instantly set off1 moving their  

legs in a natural manner1 and  drawing  
the coach after them3 when the coach    
reached the opposite edge  of the table1
 it turned sharply at a right angle1 and
 proceeded along  the adjacent edge4 ,as
 soon as it arrived opposite the place  
where the  king sat1 it stopped2 the    
page descended and opened the           
coach-door2 the  lady alighted1 and with
 a curtsey presented a petition1 which  
she held  in her hand to the king4      
,after waiting some time she again      
curtsied and  re-entered the carriage4  
,the page closed the door1 and having   
resumed  his place behind1 the coachman 
whipped his horses and drove on4 ,the   
footman1 who had previously alighted1   
ran after the carriage and jumped  up   
behind into his former place4    ,not   
content with imitating the movements of 
animals1 the mechanical  genius of the  
#agth and #ahth centuries ventured to   
perform by wheels  and pinions the      
functions of vitality4 ,we are informed 
by ,m4 ,lobat1  that ,gen4 ,degennes1 a 

,french officer who defended the colony 
of ,st4  ,christopher's against the     
,english forces1 constructed a peacock  
which  could walk about as if alive1    
pick up grains of corn from the ground1 
digest them as if they had been         
submitted to the action of the stomach1 
and afterwards discharged them in an    
altered form4 ,degennes is said to  have
 invented various machines of great use 
in navigation and gunnery1  and to have 
constructed clocks without weights or   
springs4    ,the automaton of ,degennes 
probably suggested to ,m4 ,vaucanson the
 idea  of constructing his celebrated   
duck1 which excited so much interest    
throughout ,europe1 and which was       
perhaps the most wonderful piece of     
mechanism that was ever made4           
,vaucanson's duck exactly resembled the 
living animal in size and appearance4   
,it executed accurately all its         
movements and gestures1 it ate and drank
 with avidity1 performed all  the quick 
motions of the head and throat which are

 peculiar to the  living animal1 and1   
like it1 it muddled the water which it  
drank with  its bill4 ,it produced also 
the sound of quacking in the most       
natural  manner4 ,in the anatomical     
structure of the duck1 the artist       
exhibited  the highest skill4 ,every    
bone in the real duck had its           
representative  in the automaton1 and   
its wings were anatomically exact4      
,every cavity1  apophysis1 and curvature
 was imitated1 and each bone executed   
its  proper movements4 ,when corn was   
thrown down before it1 the duck         
stretched out its neck to pick it up1 it
 swallowed it1 digested it1 and         
discharged it in a digested condition4  
,the process of digestion was  effected 
by chemical solution1 and not by        
trituration1 and the food  digested in  
the stomach was conveyed away by tubes  
to the place of its  discharge4    ,the 
automata of ,vaucanson were imitated by 
one ,du ,moulin1 a  silversmith1 who    
travelled with them through ,germany in 

#ageb1 and who  died at ,moscow in      
#agfe4 ,beckmann informs us that he saw 
several of them  after the machinery had
 been deranged2 but that the artificial 
duck1  which he regarded as the most    
ingenious1 was still able to eat1 drink1
  and move4 ,its ribs1 which were made  
of wire1 were covered with duck's       
feathers1 and the motion was            
communicated through the feet of the    
duck  by means of a cylinder and fine   
chains like that of a watch4            
,illustration3 ,fig4 #ff4               
,illustration3 ,fig4 #fg4    ,ingenious 
as all these machines are1 they sink    
into insignificance  when compared with 
the automaton chess-player1 which for a 
long time  astonished and delighted the 
whole of ,europe4 ,in the year #agfi1   
,m4  ,kempelen1 a gentleman of ,presburg
 in ,hungary1 constructed an automaton  
chess-player1 the general appearance of 
which is shown in the annexed  figures4 
,the chess-player is a figure as large  
as life1 clothed in a  ,turkish dress1  

sitting behind a large square chest or  
box1 three feet  and a half long1 two   
feet deep1 and two and a half high4 ,the
 machine  runs on castors1 and is either
 seen on the floor when the doors of the
  apartment are thrown open1 or is      
wheeled into the room previously to  the
 commencement of the exhibition4 ,the   
,turkish chess-player sits on a  chair  
fixed to the square chest3 his right arm
 rests on the table1 and  in the left he
 holds a pipe1 which is removed during  
the game1 as it is  with this hand that 
he makes the moves4 ,a chess-board1     
eighteen inches  square1 and bearing the
 usual number of pieces1 is placed      
before the  figure4 ,the exhibitor then 
announces to the spectators his         
intention  of showing them the mechanism
 of the automaton4 ,for this purpose he 
unlocks the door ,a1 ,fig4 #ff1 and     
exposes to view a small cupboard lined  
with black or dark-coloured cloth1 and  
containing cylinders1 levers1  wheels1  
pinions1 and different pieces of        

machinery1 which have the  appearance of
 occupying the whole space4 ,he next    
opens the door ,b1  ,fig4 #fg1 at the   
back of the same cupboard1 and holding a
 lighted candle  at the opening1 he     
still further displays the inclosed     
machinery to  the spectators1 placed in 
front of ,a1 ,fig4 #ff4 ,when the candle
 is  withdrawn1 the door ,b is then     
locked2 and the exhibitor proceeds to   
open the drawer ,g ,g1 ,fig4 #ff1 in    
front of the chest4 ,out of this drawer 
he takes a small box of counters1 a set 
of chess-men1 and a cushion for  the    
support of the automaton's arm1 as if   
this was the sole object of  the drawer4
 ,the two front doors ,c ,c1 of the     
large cupboard1 ,fig4 #ff1  are then    
opened1 and at the back-door ,d of the  
same cupboard1 ,fig4 #fg1  the exhibitor
 applies a lighted candle1 as before1   
for the purpose of  showing its         
interior1 which is lined with dark cloth
 like the other1  and contains only a   
few pieces of machinery4 ,the chest is  

now wheeled  round1 as in ,fig4 #fg3 the
 garments of the figure are lifted up1  
and the  door ,e in the trunk1 and      
another door ,f in the thigh1 are       
opened1 the  doors ,b and ,d having been
 previously closed4 ,when this          
exhibition of  the interior of the      
machine is over1 the chest is wheeled   
back into its  original position on the 
floor4 ,the doors ,a1 ,c1 ,c1 in front1 
and the  drawer ,g1 ,g1 are closed and  
locked1 and the exhibitor1 after        
occupying  himself for some time at the 
back of the chest1 as if he were        
adjusting  the mechanism1 removes the   
pipe from the hand of the figure1 and   
winds  up the machinery4    ,the        
automaton is now ready to play1 and when
 an opponent has been found  among the  
company1 the figure takes the first     
move4 ,at every move  made by the       
automaton1 the wheels of the machine are
 heard in action2  the figure moves its 
head1 and seems to look over every part 
of the  chess-board4 ,when it gives     

check to its opponent1 it shakes its    
head  thrice1 and only twice when it    
checks the queen4 ,it likewise shakes   
its head when a false move is made1     
replaces the adversary's piece on  the  
square from which it was taken1 and     
takes the next move itself4 ,in         
general1 though not always1 the         
automaton wins the game4    ,during the 
progress of the game1 the exhibitor     
often stands near the  machine1 and     
winds it up like a clock1 after it has  
made ten or twelve  moves4 ,at other    
times he went to a corner of the room1  
as if it were to  consult a small square
 box1 which stood open for this purpose4
    ,the chess-playing machine1 as thus 
described1 was exhibited after its      
completion in ,presburg1 ,vienna1 and   
,paris1 to thousands1 and in #aghc  and 
#aghd it was exhibited in ,london and   
different parts of ,england1  without   
the secret of its movements having been 
discovered4 ,its  ingenious inventor1   
who was a gentleman and a man of        

education1 never  pretended that the    
automaton itself really played the game4
 ,on the  contrary1 he distinctly       
stated1 8that the machine was a         
bagatelle1  which was not without merit 
in point of mechanism1 but that the     
effects  of it appeared so marvellous   
only from the boldness of the           
conception1  and the fortunate choice of
 the methods adopted for promoting the  
illusion40    ,upon considering the     
operations of this automaton1 it must   
have been  obvious that the game of     
chess was performed either by a person  
enclosed in the chest1 or by the        
exhibitor himself4 ,the first of these  
hypotheses was ingeniously excluded by  
the display of the interior  of the     
machine1 for as every part contained    
more or less machinery1  the spectator  
invariably concluded that the smallest  
dwarf could  not be accommodated within1
 and this idea was strengthened by the  
circumstance1 that no person of this    
description could be discovered  in the 

suite of the exhibitor4 ,hence the      
conclusion was drawn1  that the         
exhibitor actuated the machine either by
 mechanical means  conveyed through its 
feet1 or by a magnet concealed in the   
body of  the exhibitor4 ,that mechanical
 communication was not formed between   
the exhibitor and the figure1 was       
obvious from the fact1 that no such     
communication was visible1 and that it  
was not necessary to place the  machine 
on any particular part of the floor4    
,hence the opinion became  very         
prevalent that the agent was a magnet2  
but even this supposition  was excluded1
 for the exhibitor allowed a strong and 
well-armed  loadstone to be placed upon 
the machine during the progress of the  
game4 ,had the moving power been a      
magnet1 the whole action of the  machine
 would have been deranged by the        
approximation of a loadstone  concealed 
in the pockets of any of the spectators4
    ,as ,baron ,kempelen himself had    
admitted that there was an illusion     

connected with the performance of the   
automaton1 various persons  resumed the 
original conjecture1 that it was        
actuated by a person  concealed in its  
interior1 who either played the game of 
chess himself1  or performed the moves  
which the exhibitor indicated by        
signals4 ,a ,mr4  ,j4 ,f4 ,freyhere1 of 
,dresden1 published a book on the       
subject in #aghi1  in which he          
endeavoured to explain1 by coloured     
plates1 how the effect  was produced2   
and he concluded1 8that a well-taught   
boy very thin and  tall of his age      
7sufficiently so that he could be       
concealed in a drawer  almost           
immediately under the chess-board71     
agitated the whole40    ,in another     
pamphlet1 which had been previously     
published at ,paris in  #aghe1 the      
author not only supposed that the       
machine was put in motion  by a dwarf1 a
 famous chess-player2 but he goes so far
 as to explain  the manner in which he  
could be accommodated within the        

machine4 ,the  invisibility of the dwarf
 when the doors were opened was         
explained by  his legs and thighs being 
concealed in two hollow cylinders1 while
 the  rest of his body was out of the   
box1 and hid by the petticoats of the   
automaton4 ,when the doors were shut1   
the clacks produced by the swivel  of a 
ratchet-wheel permitted the dwarf to    
change his place1 and return  to the box
 unheard2 and while the machine is      
wheeled about the room1  the dwarf had  
an opportunity of shutting the trap     
through which he  passed into the       
machine4 ,the interior of the figure was
 next shown1 and  the spectators were   
satisfied that the box contained no     
living agent4    ,although these views  
were very plausible1 yet they were never
 generally  adopted2 and when the       
automaton was exhibited in ,great       
,britain in #ahai  and #ahbj1 by ,m4    
,maelzel1 it excited as intense an      
interest as when it  was first produced 
in ,germany4 ,there can be little doubt1

 however1  that the secret has been     
discovered2 and an anonymous writer has 
shown in a pamphlet1 entitled 8,an      
attempt to analyse the ,automaton       
,chess-player of ,m4 ,kempelen10 that it
 is capable of accommodating an         
ordinary sized man2 and he has explained
 in the clearest manner how the         
inclosed player takes all the different 
positions1 and performs all the  motions
 which are necessary to produce the     
effects actually observed4  ,the        
following is the substance of his       
observations3--,the drawer ,g ,g  when  
closed does not extend to the back of   
the chest1 but leaves a  space ,o1      
behind it 7see ,figs4 #gd1 #ge1 and     
#gf71 fourteen inches broad1  eight     
inches high1 and three feet eleven      
inches long4 ,this space is  never      
exposed to the view of spectators4 ,the 
small cupboard seen at ,a  is divided   
into two parts1 by a door or screen ,i1 
,fig4 #gc1 which is  moveable upon a    
hinge1 and is so constructed that it    

closes at the same  instant that ,b is  
closed4 ,the whole of the front         
compartment as far as  ,i is occupied   
with the machinery ,h4 ,the other       
compartment behind ,i is  empty1 and    
communicates with the space ,o behind   
the drawer1 the floor  of this division 
being removed4 ,the back of the great   
cupboard ,c ,c is  double1 and the part 
,p ,q1 to which the quadrants are       
attached1 moves  on a joint ,q1 at the  
upper part1 and forms when raised an    
opening ,s1  between the two cupboards1 
by carrying with it part of the         
partition  ,r1 which consists of cloth  
tightly stretched4 ,the false back is   
shown  closed in ,fig4 #gd1 while ,fig4 
#ge shows the same back raised1 so as to
  form the opening ,s between the       
chambers4    ,when the spectator is     
allowed to look into the trunk of the   
figure by  lifting up the dress1 as in  
,fig4 #ge1 it will be observed that a   
great  part of the space is occupied by 
an inner trunk ,n1 ,figs4 #ge1 #gf1     

which  passes off to the back in the    
form of an arch1 and conceals from the  
spectators a portion of the interior4   
,this inner trunk ,n opens and          
communicates with the chest by an       
aperture ,t1 ,fig4 #gg1 about twelve    
inches broad and fifteen high4 ,when the
 false back is raised1 the two          
cupboards1 the trunk ,n1 and the space  
,o behind the drawer1 are all  connected
 together4    ,illustration3 ,no4 #fh4  
,illustration3 ,no4 #fi4    ,the        
construction of the interior being thus 
understood1 the  chess-player may be    
introduced into the chest through the   
sliding panel  ,u1 ,fig4 #gd4 ,he will  
then raise the false back of the large  
cupboard1  and assume the position      
represented by the shaded figure in     
,figs4 #fh  and #fi4 ,things being in   
this state1 the exhibitor is ready to   
begin his  process of deception4 ,he    
first opens the door ,a of the small    
cupboard1  and from the crowded and very
 ingenious disposition of the machinery 

within it1 the eye is unable to         
penetrate far beyond the opening1 and   
the spectator concludes1 without any    
hesitation1 that the whole of the       
cupboard is filled1 as it appears to be1
 with similar machinery4 ,this  false   
conclusion is greatly corroborated by   
observing the glimmering  light which   
plays among the wheel-work when the door
 ,b is opened1 and a  candle held at the
 opening4 ,this mode of exhibiting the  
interior of the  cupboard satisfies the 
spectator also1 that no opaque body1    
capable of  holding or concealing any of
 the parts of a hidden agent1 is        
interposed  between the light and the   
observer4 ,the door ,b is now locked and
 the  screen ,i closed1 and as this is  
done at the time that the light is      
withdrawn1 it will wholly escape        
observation4    ,the door ,b is so      
constructed as to close by its own      
weight1 but as the  head of the         
chess-player will soon be placed very   
near it1 the secret  would be disclosed 

if1 in turning round1 the chest door    
should by any  accident fly open4 ,this 
accident is prevented by turning the    
key1 and1  lest this little circumstance
 should excite notice1 it would probably
  be regarded as accidental1 as the keys
 were immediately wanted for the  other 
locks4    ,as soon as the door ,b is    
locked1 and the screen ,i closed1 the   
secret  is no longer exposed to hazard1 
and the exhibitor proceeds to lead  the 
minds of the spectators still farther   
from the real state of  things4 ,the    
door ,a is left open to confirm the     
opinion that no person  is concealed    
within1 and that nothing can take place 
in the interior  without being observed4
    ,illustration3 ,fig4 #gj4    ,the   
drawer ,,gg is now opened1 apparently   
for the purpose of looking  at the      
chess-men1 cushion1 and counters1 which 
it contains2 but  the real object of it 
is to give time to the player to change 
his  position1 as shown in the annexed  
figure1 and to replace the false  back  

and partition preparatory to the opening
 of the great cupboard4  ,the           
chess-player1 as the figure shows1      
occupies with his body the  back        
compartment of the small cupboard1 while
 his legs and thighs  are contained in  
the space ,o1 behind the drawer ,,gg1   
his body being  concealed by the screen 
,i1 and his limbs by the drawer ,,gg4   
,the great cupboard ,,cc is now opened1 
and there is so little machinery  in it1
 that the eye instantly discovers that  
no person is concealed in  it4 ,to make 
this more certain1 however1 a door is   
opened at the back1  and a lighted      
candle held to it1 to allow the         
spectators to explore  every corner and 
recess4    ,the front doors of the great
 and small cupboard being left open1    
the chest is wheeled round to show the  
trunk of the figure1 and the  bunch of  
keys is allowed to remain in the door   
,d1 as the apparent  carelessness of    
such a proceeding will help to remove   
any suspicion  which may have been      

excited by the locking of the door ,b4  
,when the drapery of the figure has been
 raised1 and the doors ,e and ,f  in the
 trunk and thigh opened1 the chest is   
wheeled round again into  its original  
position1 and the doors ,e and ,f       
closed4 ,in the mean time  the player   
withdraws his legs from behind the      
drawer1 as he cannot so  easily do this 
when the drawer ,,gg is pushed in4      
,in all these operations1 the spectator 
flatters himself that he has  seen in   
succession every part of the chest1     
while in reality some parts  have been  
wholly concealed from his view1 and     
others but imperfectly  shown1 while at 
the present time nearly half of the     
chest is excluded  from view4           
,illustration3 ,no4 #ga4                
,illustration3 ,no4 #gb4    ,when the   
drawer ,g ,g is pushed in1 and the doors
 ,a and ,c closed1 the  exhibitor       
adjusts the machinery at the back1 in   
order to give time  to the player to    
take the position shown in a front view 

in ,fig4 #ga1  and in profile in ,fig4  
#gb4 ,in this position he will          
experience no  difficulty in executing  
every movement made by the automaton4   
,as his  head is above the chess-board1 
he will see through the waistcoat of the
  figure1 as easily as through a veil1  
the whole of the pieces on the  board1  
and he can easily take up and put down a
 chess-man without any  other mechanism 
than that of a string communicating with
 the finger of  the figure4 ,his right  
hand1 being within the chest1 may be    
employed to  keep in motion the         
wheel-work for producing the noise which
 is heard  during the moves1 and to     
perform the other movements of the      
figure1  such as that of moving the     
head1 tapping on the chest1 c4    ,a    
very ingenious contrivance is adopted to
 facilitate the introduction  of the    
player's left arm into the arm of the   
figure4 ,to permit this1  the arm of the
 figure requires to be drawn backwards2 
and for the  purpose of concealing1 and 

at the same time explaining this        
strained  attitude1 a pipe is           
ingeniously placed in the automaton's   
hand4 ,for  this reason the pipe is not 
removed till all the other arrangements 
are  completed4 ,when every thing has   
been thus prepared1 the pipe is taken   
from the figure1 and the exhibitor winds
 up1 as it were1 the inclosed           
machinery1 for the double purpose of    
impressing upon the company the  belief 
that the effect is produced by          
machinery1 and of giving a signal  to   
the player to put in motion the head of 
the automaton4    ,illustration3 ,fig4  
#gc4    ,illustration3 ,fig4 #gd4       
,this ingenious explanation of the chess
 automaton is1 our author  states1      
greatly confirmed by the regular and    
undeviating mode of  disclosing the     
interior of the chest2 and he also shows
 that the facts  which have been        
observed respecting the winding up of   
the machine1  8afford positive proof    
that the axis turned by the key is quite

 free  and unconnected either with a    
spring or weight1 or any system of      
machinery40    ,in order to make the    
preceding description more intelligible1
 ,i shall  add the following more       
detailed explanation of the figures4    
,fig4 #ff is a perspective view of the  
automaton seen in front with all  the   
doors thrown open4    ,fig4 #fg is an   
elevation of the automaton1 as seen from
 behind4    ,fig4 #fh is an elevation of
 the front of the chest1 the shaded     
figure  representing the inclosed player
 in his first position1 or when the     
door ,a is opened4    ,fig4 #fi is a    
side elevation1 the shaded figure       
representing the player  in the same    
position4    ,fig4 #gj is a front       
elevation1 the shaded figure showing the
 player in  his second position1 or that
 which he takes after the door ,b and   
screen  ,i are closed1 and the great    
cupboard opened4    ,fig4 #ga is a front
 elevation1 the shaded figure showing   
the player in  his third position1 or   

that in which he plays the game4        
,fig4 #gb is a side elevation showing   
the figure in the same position4        
,fig4 #gc is a horizontal section of the
 chest through the line ,,ww in  ,fig4  
#ga4    ,fig4 #gd is a vertical section 
of the chest through the line ,,xx in   
,fig4  #gc4    ,illustration3 ,fig4 #ge4
    ,illustration3 ,fig4 #gf4    ,fig4  
#ge is a vertical section through the   
line ,,yy ,fig4 #ga1 showing the  false 
back closed4    ,fig4 #gf is a similar  
vertical section showing the false back 
raised4    ,the following letters of    
reference are employed in all the       
figures3--    ,a4 ,front door of the    
small cupboard4    ,b4 ,back door of    
ditto4    ,c ,c4 ,front doors of large  
cupboard4    ,d4 ,back door of ditto4   
,e4 ,door of ditto4    ,f4 ,door of the 
thigh4    ,g ,g4 ,the drawer4    ,h4    
,machinery in front of the small        
cupboard4    ,i4 ,screen behind the     
machinery4    ,k4 ,opening caused by the
 removal of part of the floor of the    

small  cupboard4    ,l4 ,a box which    
serves to conceal an opening in the     
floor of the large  cupboard1 made to   
facilitate the first position2 and which
 also serves  as a seat for the third   
position4    ,m4 ,a similar box to      
receive the toes of the player in the   
first  position4    ,n4 ,the inner chest
 filling up part of the trunk4    ,o4   
,the space behind the drawer4    ,p ,q4 
,the false back turning on a joint at   
,q4    ,r4 ,part of the partition formed
 of cloth stretched tight1 which is     
carried up by the false back to form the
 opening between the chambers4    ,s4   
,the opening between the chambers4      
,t4 ,the opening connecting the trunk   
and chest1 which is partly  concealed by
 the false back4    ,u4 ,panel which is 
slipt aside to admit the player4        
99       99       99       99       99  
,various pieces of mechanism of         
wonderful ingenuity have been           
constructed for the purposes of drawing 
and writing4 ,one of these1  invented by

 ,m4 ,le ,droz1 the son of the          
celebrated ,droz of ,chaux le  ,fonds1  
has been described by ,mr4 ,collinson4  
,the figure was the size  of life4 ,it  
held in its hand a metallic style1 and  
when a spring was  touched1 so as to    
release a detent1 the figure immediately
 began to  draw upon a card of ,dutch   
vellum previously laid under its hand4  
,after the drawing was executed on the  
first card1 the figure rested4  ,other  
five cards were then put in1 in         
succession1 and upon these it           
delineated in the same manner different 
subjects4 ,on the first card it  drew   
8elegant portraits and likenesses of the
 king and queen facing  each other20 and
 ,mr4 ,collinson remarks1 that it was   
curious to observe  with what precision 
the figure lifted up its pencil in its  
transition  from one point of the       
drawing to another1 without making the  
slightest  mistake4    ,m4 ,maillardet  
has executed an automaton which both    
writes and draws4  ,the figure of a boy 

kneeling on one knee holds a pencil in  
his hand4  ,when the figure begins to   
work1 an attendant dips the pencil in   
ink1  and adjusts the drawing-paper upon
 a brass tablet4 ,upon touching a       
spring1 the figure proceeds to write1   
and when the line is finished1  its hand
 returns to dot and stroke the letters  
when necessary4 ,in this  manner it     
executes four beautiful pieces of       
writing in ,french and  ,english1 and   
three landscapes1 all of which occupy   
about one hour4    ,one of the most     
popular pieces of mechanism which we    
have seen is the  magician constructed  
by ,m4 ,maillardet for the purpose of   
answering  certain given questions4 ,a  
figure dressed like a magician appears  
seated at the bottom of a wall1 holding 
a wand in one hand1 and a book  in the  
other4 ,a number of questions ready     
prepared are inscribed on  oval         
medallions1 and the spectator takes any 
of these which he chooses1  and to which
 he wishes an answer1 and having placed 

it in a drawer  ready to receive it1 the
 drawer shuts with a spring till the    
answer  is returned4 ,the magician then 
rises from his seat1 bows his head1     
describes circles with his wand1 and1   
consulting the book as if in deep       
thought1 he lifts it towards his face4  
,having thus appeared to ponder  over   
the proposed question1 he raises his    
wand1 and striking with  it the wall    
above his head1 two folding-doors fly   
open1 and display  an appropriate answer
 to the question4 ,the doors again      
close1 the  magician resumes his        
original position1 and the drawer opens 
to return  the medallion4 ,there are    
twenty of these medallions1 all         
containing  different questions1 to     
which the magician returns the most     
suitable  and striking answers4 ,the    
medallions are thin plates of brass of  
an  elliptical form1 exactly resembling 
each other4 ,some of the medallions     
have a question inscribed on each side1 
both of which the magician  answers in  

succession4 ,if the drawer is shut      
without a medallion being  put into it1 
or if a blank medallion1 viz41 one which
 contains no  question1 is put into the 
drawer1 the magician rises1 consults his
  book1 shakes his head1 and resumes his
 seat4 ,the folding-doors remain  shut1 
and the drawer is returned empty4 ,if   
two medallions are put into  the drawer 
together1 an answer is returned only to 
the lower one4 ,when  the machinery is  
wound up1 the movements continue about  
an hour1 during  which time about fifty 
questions may be answered4 ,the method  
by which  the different medallions acted
 upon the machinery1 so as to produce   
the  proper answers to the questions    
which they bore1 was of course kept a   
secret by the inventor1 but it was      
discovered by ,mr4 ,brockedon1 who  has 
kindly communicated to me an account of 
it4    ,upon examining the edge of the  
circular medallions1 ,mr4 ,brockedon    
discovered in all of them1 except the   
blanks1 a small hole almost  concealed  

by the milling4 ,this led ,mr4          
,brockedon to examine the  receptacle   
for the medallion in the drawer1 and he 
observed the edge  of a pin flush with  
the edge of the receptacle1 whence the  
pin was  protruded by the machine into  
the holes in the medallion1 the depth of
  the hole regulating the answer4 ,in   
order to prove this1 ,mr4 ,b4 cut a     
slip from a cedar pencil small enough to
 enter easily the holes in the          
medallion1 if he found them to be of    
different depths4 ,as the blank         
medallions had no hole1 and produced    
only a shake of the magician's  head1   
,mr4 ,b4 took a medallion with a        
question1 and having plugged the  hole  
with a bit of cedar1 he cut it flush1   
and having placed it in the  receptacle1
 the conjuror shook his head1 and thus  
bore testimony to the  truth of ,mr4    
,brockedon's discovery4    ,m4          
,maillardet has constructed various     
other automata1 representing  insects   
and other animals4 ,one of these was a  

spider entirely made of  steel1 which   
exhibited all the movements of the      
animal4 ,it ran on the  surface of a    
table during three minutes1 and to      
prevent it from running  off1 its course
 always tended towards the centre of the
 table4 ,he  constructed likewise a     
caterpillar1 a lizard1 a mouse1 and a   
serpent4  ,the serpent crawls about in  
every direction1 opens its mouth1       
hisses1  and darts out its tongue4      
,ingenious and beautiful as all these   
pieces of mechanism are1 and  surprising
 as their effects appear even to        
scientific spectators1 the  principal   
object of their inventors was to        
astonish and amuse the  public4 ,we     
should form an erroneous judgment1      
however1 if we suppose  that this was   
the only result of the ingenuity which  
they displayed4  ,the passion for       
automatic exhibitions1 which            
characterized the #ahth  century1 gave  
rise to the most ingenious mechanical   
devices1 and  introduced among the      

higher orders of artists habits of nice 
and  accurate execution in the formation
 of the most delicate pieces of         
machinery4 ,the same combination of the 
mechanical powers which made the  spider
 crawl1 or which waved the tiny rod of  
the magician1 contributed  in future    
years to purposes of higher import4     
,those wheels and pinions1  which almost
 eluded our senses by their minuteness1 
re-appeared in the  stupendous mechanism
 of our spinning-machines and our       
steam-engines4  ,the elements of the    
tumbling-puppet were revived in the     
chronometer1  which now conducts our    
navy through the ocean2 and the         
shapeless wheel  which directed the hand
 of the drawing automaton has served1 in
 the  present age1 to guide the         
movements of the tambouring engine4     
,those  mechanical wonders1 which in one
 century enriched only the conjuror  who
 used them1 contributed in another to   
augment the wealth of the  nation2 and  
those automatic toys1 which once amused 

the vulgar1 are now  employed in        
extending the power and promoting the   
civilization of our  species4 ,in       
whatever way1 indeed1 the power of      
genius may invent or  combine1 and to   
whatever low or even ludicrous purposes 
that invention  or combination may be   
originally applied1 society receives a  
gift which  it can never lose2 and      
though the value of the seed may not be 
at once  recognized1 and though it may  
lie long unproductive in the ungenial   
till of human knowledge1 it will some   
time or other evolve its germ1  and     
yield to mankind its natural and        
abundant harvest4    ,did the limits of 
so popular a volume as this ought to be 
permit it1 ,i  should have proceeded to 
give a general description of some of   
these  extraordinary pieces of          
machinery1 the construction and effects 
of  which never fail to strike the      
spectator with surprise4 ,this1 however1
  would lead me into a field too        
extensive1 and ,i shall therefore       

confine  myself to a notice of three    
very remarkable pieces of mechanism     
which  are at present very little known 
to the general reader1 viz41 the        
tambouring machine of ,mr4 ,duncan1 the 
statue-turning machine of ,mr4  ,watt1  
and the calculating machinery of ,mr4   
,babbage4    ,the tambouring of muslins1
 or the art of producing upon them      
ornamental  flowers and figures1 has    
been long known and practised in        
,britain  as well as in other countries2
 but it was not long before the year    
#agij1 that it became an object of      
general manufacture in the west of      
,scotland1 where it was chiefly carried 
on4 ,at first it was under the          
direction of foreigners2 but their aid  
was not long necessary1 and  it speedily
 extended to such a degree as to occupy1
 either wholly or  partially1 more than 
#bj1jjj females4 ,many of these         
labourers lived  in the neighbourhood of
 ,glasgow1 which was the chief seat of  
the  manufacture2 but others were       

scattered through every part of         
,scotland1  and supplied by agents with 
work and money4 ,in ,glasgow1 a         
tambourer  of ordinary skill could not  
in general earn more than five or six   
shillings a week by constant            
application2 but to a labouring artisan1
  who had several daughters1 even these 
low wages formed a source of  great     
wealth4 ,at the age of five years1 a    
child capable of handling a  needle was 
devoted to tambouring1 even though it   
could not earn more  than a shilling or 
two in a week2 and the consequence of   
this was1 that  female children were    
taken from school1 and rendered totally 
unfit for  any social or domestic duty4 
,the tambouring population1 was1        
therefore1  of the worst kind1 and it   
must have been regarded as a blessing   
rather  than as a calamity1 when the    
work which they performed was entrusted 
to  regular machinery4    ,mr4 ,john    
,duncan of ,glasgow1 the inventor of the
 tambouring machinery1  was one of those

 unfortunate individuals who benefit    
their species  without benefiting       
themselves1 and who died in the meridian
 of life1  the victim of poverty and of 
national ingratitude4 ,he conceived the 
idea of bringing into action a great    
number of needles at the same  time1 in 
order to shorten the process by manual  
labour2 but he at  first was perplexed  
about the diversification of the        
pattern4 ,this  difficulty1 however1 he 
soon surmounted by employing two forces 
at  right angles to each other1 which   
gave him a new force in the direction   
of the diagonal of the parallelogram1   
whose sides were formed by the  original
 forces4 ,his first machine was very    
imperfect2 but after two  years' study1 
he formed a company1 at whose expense   
six improved  machines were put in      
action1 and who secured the invention by
 a patent4  ,at this time the idea of   
rendering the machine automatic had     
scarcely  occurred to him2 but he       
afterwards succeeded in accomplishing   

this  great object1 and the tambouring  
machines were placed under the          
surveillance of a steam-engine4 ,another
 patent was taken for these             
improvements4 ,the reader who desires to
 have a minute account of these         
improvements1 and of the various parts  
of the machinery1 will be amply         
gratified by perusing the inventor's own
 account of the machinery  in the       
article ,,chainwork in the ,edinburgh   
,encyclopdia4 ,at present  it will be   
sufficient to state1 that the muslin to 
be tamboured was  suspended vertically  
in a frame1 which was capable of being  
moved both  in a vertical and a         
horizontal direction4 ,sixty or more    
needles lying  horizontally occupied a  
frame in front of the muslin web4 ,each 
of these  working needles1 as they are  
called1 was attended by a               
feeding-needle1  which1 by a circular   
motion round the working-needle1 lodged 
upon the  stem of the latter the loop of
 the thread4 ,the sixty needles then    

penetrated the web1 and1 in order that  
they might return again without         
injuring the fabric1 the barb or eye of 
the needle1 which resembled the  barb of
 a fishing-hook1 was shut by a slider4  
,the muslin web then took  a new        
position by means of the machinery that 
gave it its horizontal  and vertical    
motion1 so that the sixty needles       
penetrated it1 at their  next movement1 
at another point of the figure or       
flower4 ,this operation  went on till   
sixty flowers were completed4 ,the web  
was then slightly  wound up1 that the   
needles might be opposite that part of  
it on which  they were to work another  
row of flowers4    ,the flowers were    
generally at an inch distance1 and the  
rows were  placed so that the flowers   
formed what are called diamonds4 ,there 
were  seventy-two rows of flowers in a  
yard1 so that in every square yard      
there were nearly #djjj flowers1 and in 
every piece of ten yards long  #dj1jjj4 
,the number of loops or stitches in a   

flower varied with the  pattern1 but on 
an average there were about thirty4     
,hence the number  of stitches in a yard
 were #abj1jjj1 and the number in a     
piece is  #a1bjj1jjj4 ,the average work 
done in a week by one machine was       
fifteen  yards1 or #fj1jjj flowers1 or  
#a1hjj1jjj stitches2 and by comparing   
this  with the work done by one person  
with the hand1 it appeared that the     
machine enabled one person to do the    
work of twenty-four persons4    ,one of 
the most curious and important          
applications of machinery  to the arts  
which has been suggested in modern      
times1 was made by  the late ,mr4 ,watt1
 in the construction of a machine for   
copying or  reducing statues and        
sculpture of all kinds4 ,the art of     
multiplying  busts and statues1 by casts
 in plaster of ,paris1 has been the     
means  of diffusing a knowledge of this 
branch of the fine arts2 but from  the  
fragile nature of the material1 the     
copies thus produced were  unfit for    

exposure to the weather1 and therefore  
ill calculated for  ornamenting public  
buildings1 or for perpetuating the      
memory of public  achievements4 ,a      
machine1 therefore1 which is capable of 
multiplying  the labours of the sculptor
 in the durable materials of marble or  
of  brass was a desideratum of the      
highest value1 and one which could  have
 been expected only from a genius of the
 first order4 ,during many  years ,mr4  
,watt carried on his labours in secret1 
and he concealed  even his intention of 
constructing such a machine4 ,after he  
had made  considerable progress in its  
execution1 and had thought of securing  
his invention by a patent1 he learned   
that an ingenious individual  in his own
 neighbourhood had been long occupied in
 the same pursuit2  and ,mr4 ,watt      
informed me that he had every reason to 
believe that  this gentleman was        
entirely ignorant of his labours4 ,a    
proposal was  then made that the two    
inventors should combine their talents1 

and  secure the privilege by a joint    
patent2 but ,mr4 ,watt had experienced  
so frequently the fatal operation of our
 patent laws1 that he saw many          
difficulties in the way of such an      
arrangement1 and he was unwilling1  at  
his advanced age1 to embark in a project
 so extensive1 and which  seemed to     
require for its successful prosecution  
all the ardour and  ambition of a       
youthful mind4 ,the scheme was therefore
 abandoned2  and such is the unfortunate
 operation of our patent laws1 that the 
circumstance of two individuals having  
made the same invention has  prevented  
both from bringing it to perfection1 and
 conferring a great  practical benefit  
upon their species4 ,the machine which  
,mr4 ,watt had  constructed had actually
 executed some excellent pieces of work4
 ,i  have seen in his house at          
,heathfield copies of basso-relievos1   
and  complete statues of a small size2  
and some of his friends have in their   
possession other specimens of its       

performance4    ,of all the machines    
which have been constructed in modern   
times1  the calculating-machine is      
doubtless the most extraordinary4       
,pieces  of mechanism for performing    
particular arithmetical operations have 
been long ago constructed1 but these    
bear no comparison either in  ingenuity 
or in magnitude to the grand design     
conceived and nearly  executed by ,mr4  
,babbage4 ,great as the power of        
mechanism is known to  be1 yet we       
venture to say1 that many of the most   
intelligent of our  readers will        
scarcely admit it to be possible that   
astronomical and  navigation tables can 
be accurately computed by machinery2    
that the  machine can itself correct the
 errors which it may commit2 and that   
the results of its calculations1 when   
absolutely free from error1  can be     
printed off1 without the aid of human   
hands1 or the operation  of human       
intelligence4 ,all this1 however1 ,mr4  
,babbage's machine can  do2 and as ,i   

have had the advantage of seeing it     
actually calculate1  and of studying its
 construction with ,mr4 ,babbage        
himself1 ,i am able  to make the above  
statement on personal observation4 ,the 
calculating  machine now constructing   
under the superintendence of the        
inventor  has been executed at the      
expense of the ,british ,government1 and
 is  of course their property4 ,it      
consists essentially of two parts2 a    
calculating part1 and a printing part1  
both of which are necessary to  the     
fulfilment of ,mr4 ,babbage's views2 for
 the whole advantage would be  lost if  
the computations made by the machine    
were copied by human hands  and         
transferred to types by the common      
process4 ,the greater part of the       
calculating machinery is already        
constructed1 and exhibits workmanship   
of such extraordinary skill and beauty1 
that nothing approaching to it  has been
 witnessed4 ,in order to execute it1    
particularly those parts of  the        

apparatus which are dissimilar to any   
used in ordinary mechanical             
constructions1 tools and machinery of   
great expense and complexity have  been 
invented and constructed2 and in many   
instances contrivances of  singular     
ingenuity have been resorted to which   
cannot fail to prove  extensively useful
 in various branches of the mechanical  
arts4    ,the drawings of this          
machinery1 which form a large part of   
the work1  and on which all the         
contrivance has been bestowed1 and all  
the  alterations made1 cover upwards of 
#djj square feet of surface1 and  are   
executed with extraordinary care and    
precision4    ,in so complex a piece of 
mechanism1 in which interrupted motions 
are  propagated simultaneously along a  
great variety of trains of mechanism1   
it might have been supposed that        
obstructions would arise1 or even       
incompatibilities occur1 from the       
impracticability of foreseeing  all the 
possible combinations of the parts2 but 

this doubt has been  entirely removed1  
by the constant employment of a system  
of mechanical  notation invented by ,mr4
 ,babbage1 which places distinctly in   
view1 at  every instant1 the progress of
 motion through all the parts of this or
  any other machine1 and by writing down
 in tables the times required for  all  
the movements1 this method renders it   
easy to avoid all risk of two  opposite 
actions arriving at the same instant at 
any part of the engine4    ,in the      
printing part of the machine less       
progress has been made in the  actual   
execution than in the calculating part4 
,the cause of this is  the greater      
difficulty of its contrivance1 not for  
transferring the  computations from the 
calculating part to the copper or other 
plate  destined to receive it1 but for  
giving to the plate itself that number  
and variety of movements which the forms
 adopted in printed tables may  call for
 in practice4    ,the practical object  
of the calculating engine is to compute 

and print  a great variety and extent of
 astronomical and navigation tables1    
which could not be done without enormous
 intellectual and manual  labour1 and   
which1 even if executed by such labour1 
could not be  calculated with the       
requisite accuracy4 ,mathematicians1    
astronomers1  and navigators1 do not    
require to be informed of the real value
 of such  tables2 but it may be proper  
to state1 for the information of others1
  that seventeen large folio volumes of 
logarithmic tables alone were           
calculated1 at an enormous expense1 by  
the ,french ,government2 and that  the  
,british ,government regarded these     
tables to be of such national  value1   
that they proposed to the ,french ,board
 of ,longitude to print  an abridgement 
of them at the joint expense of the two 
nations1 and  offered to advance #ejjjl4
 for that purpose4 ,besides logarithmic 
tables1 ,mr4 ,babbage's machine will    
calculate tables of the powers  and     
products of numbers1 and all            

astronomical tables for determining  the
 positions of the sun1 moon1 and        
planets2 and the same mechanical        
principles have enabled him to integrate
 innumerable equations of  finite       
differences1 that is1 when the equation 
of differences is given1  he can1 by    
setting an engine1 produce at the end of
 a given time  any distant term which   
may be required1 or any succession of   
terms  commencing at a distant point4   
,besides the cheapness and celerity with
 which this machine will perform  its   
work1 the absolute accuracy of the      
printed results deserves  especial      
notice4 ,by peculiar contrivances1 any  
small error produced by  accidental     
dust1 or by any slight inaccuracy in one
 of the wheels1 is  corrected as soon as
 it is transmitted to the next1 and this
 is done  in such a manner as           
effectually to prevent any accumulation 
of small  errors from producing an      
erroneous figure in the result4    ,in  
order to convey some idea of this       

stupendous undertaking1 we may  mention 
the effects produced by a small trial   
engine constructed by  the inventor1 and
 by which he computed the following     
table from the  formula x#b  x  #da4    
,the figures1 as they were calculated by
 the  machine1 were not exhibited to the
 eye as in sliding-rules and similar    
instruments1 but were actually presented
 to the eye on two opposite  sites of   
the machine1 the number #chc1 for       
example1 appearing in figures  before   
the person employed in copying4         
,table calculated by a small ,trial     
,engine4       #da   #aca   #chc    #gig
   #acgc     #dc   #aea   #dba    #hec  
#addg     #dg   #agc   #dfa    #iaa     
#aebc     #ec   #aig   #ejc    #iga     
#afja     #fa   #bbc   #edg   #ajcc     
#afha     #ga   #bea   #eic   #ajig     
#agfc     #hc   #bha   #fda   #aafc     
#ahdg     #ig   #cac   #fia   #abca     
#aicc    #aac   #cdg   #gdc   #acja     
#bjba    ,while the machine was occupied
 in calculating this table1 a friend of 

the inventor undertook to write down the
 numbers as they appeared4  ,in         
consequence of the copyist writing      
quickly1 he rather more than  kept pace 
with the engine1 but as soon as five    
figures appeared1 the  machine was at   
least equal in speed to the writer4 ,at 
another trial  thirty-two numbers of the
 same table were calculated in the space
 of  two minutes and thirty seconds2 and
 as these contained eighty-two  figures1
 the engine produced thirty-three       
figures every minute1 or  more than one 
figure in every two seconds4 ,on another
 occasion it  produced forty-four       
figures per minute4 ,this rate of       
computation  could be maintained for any
 length of time2 and it is probable that
 few  writers are able to copy with     
equal speed for many hours together4    
,some of that class of individuals who  
envy all great men1 and deny all  great 
inventions1 have ignorantly stated that 
,mr4 ,babbage's invention  is not new4  
,the same persons1 had it suited their  

purpose1 would  have maintained that the
 invention of spectacles was an         
anticipation  of the telescope2 but even
 this is more true than the allegation  
that the arithmetical machines of       
,pascal and others were the types  of   
,mr4 ,babbage's engine4 ,the object of  
these machines was entirely  different4 
,their highest functions were to perform
 the operations of  common arithmetic4  
,mr4 ,babbage's engine1 it is true1 can 
perform these  operations also1 and can 
extract the roots of numbers1 and       
approximate  to the roots of equations1 
and even to their impossible roots4 ,but
  this is not its object4 ,its function1
 in contradistinction to that  of all   
other contrivances for calculating1 is  
to embody in machinery  the method of   
differences1 which has never before been
 done2 and the  effects which it is     
capable of producing1 and the works     
which in the  course of a few years we  
expect to see it execute1 will place it 
at an  infinite distance from all other 

efforts of mechanical genius4#cc     #cc
 ,a popular account of this engine will 
be found in ,mr4 ,babbage's             
interesting volume ,on the ,economy of  
,manufactures1 lately published4        
,,letter ,,xii4     ,wonders of         
chemistry--,origin1 progress1 and       
objects of alchemy--,art   of breathing 
fire--,employed by ,barchochebas1       
,eunus1 c4--,modern   method--,art of   
walking upon burning coals and red-hot  
iron1 and of   plunging the hands in    
melted lead and boiling water--,singular
 property   of boiling tar--,workmen    
plunge their hands in melted            
copper--,trial   of ordeal by           
fire--,aldini's incombustible           
dresses--,examples of their   wonderful 
power in resisting flame--,power of     
breathing and enduring   air of high    
temperatures--,experiments made by ,sir 
,joseph ,banks1 ,sir   ,charles         
,blagden1 and ,mr4 ,chantrey4           
,chemistry has from its infancy been    
pre-eminently the science of  wonders4  

,in her laboratory the alchemist and the
 magician have revelled  uncontrolled1  
and from her treasures was forged the   
sceptre which was  so long and so       
fatally wielded over human reason4 ,the 
changes which  take place in the bodies 
immediately around us are too few in    
number  and too remote from observation 
to excite much of our notice2 but when  
the substances procured directly from   
nature1 or formed casually by  art1     
become objects of investigation1 they   
exhibit in their simple or  combined    
actions the most extraordinary effects4 
,the phenomena which  they display1 and 
the products which they form1 so little 
resemble  those with which we are       
familiar1 that the most phlegmatic and  
the  least speculative observer must    
have anticipated from them the creation 
of new and valuable compounds4 ,it can  
scarcely1 therefore1 be a  matter of    
surprise that minds of the highest      
order1 and spirits of  the loftiest     
ambition1 should have sought in the     

transmutations of  chemistry for those  
splendid products which were conceived  
to be most  conducive to human          
happiness4    ,the disciple of ,mammon  
grew pale over his crucible in his      
ardour to  convert the baser metals into
 gold2 the philosopher pined in secret  
for the universal solvent which might   
develop the elements of the  precious   
stones and yield to him the means of    
their production2 and the               
philanthropist aspired after a universal
 medicine1 which might arrest  disease  
in its course1 and prolong indefinitely 
the life of man4 ,to  us1 who live under
 the meridian of knowledge1 such        
expectations must  appear as            
presumptuous as they were delusive2 but 
when we consider  that gold and silver  
were actually produced by chemical      
processes from  the rude ores of lead   
and copper--that some of the most       
refractory  bodies had yielded to the   
disintegrating and solvent powers of    
chemical  agents1 and that the mercurial

 preparations of the ,arabian physicians
  had operated like charms in the cure  
of diseases that had resisted  the      
feeble medicines of the times1 we may   
find some apology for the  extravagant  
expectations of the alchemists4    ,an  
object of lofty pursuit1 even if it be  
one of impossible attainment1  is not   
unworthy philosophical ambition4 ,though
 we cannot scale the  summit of the     
volcanic cone1 we may yet reach its     
heaving flanks2 and  though we cannot   
decompose its loftiest fires1 we may yet
 study the  lava which they have melted 
and the products which they have        
sublimed4  ,in like manner1 though the  
philosopher's stone has not been found1 
chemistry has derived rich accessions   
from its search2--though the  general   
solvent has not been obtained1 yet the  
diamond and the gems  have surrendered  
to science their adamantine             
strength2--and though  the elixir of    
life has never been distilled1 yet other
 medicines have  soothed the 8ills which

 flesh is heir to10 and prolonged in no 
slight  degree the average term of our  
existence4    ,thus far the pursuits of 
the alchemist were honourable and       
useful2  but when his calling was       
followed1 as it soon was1 by men        
prodigal  of fortune and of character1  
science became an instrument of crime2  
secrets unattained were bartered for the
 gold of the credulous and the          
ignorant1 and books innumerable were    
composed to teach these pretended       
secrets to the world4 ,an intellectual  
reaction1 however1 soon took  place2 and
 those very princes who had sought to   
fill their exhausted  treasuries at the 
furnace of the chemist1 were the first  
to enact  laws against the frauds which 
they had encouraged1 and to dispel the  
illusions which had so long deceived    
their subjects4    ,but even when the   
moral atmosphere of ,europe was thus    
disinfected1  chemistry supplied the    
magician with his most lucrative        
wonders1 and  those who could no longer 

delude the public with dreams of wealth 
and  longevity1 now sought to amuse and 
astonish them by the exhibition  of     
their skill4 ,the narrow limits of this 
volume will not permit me  to give even 
a general view of those extraordinary   
effects which  this popular science can 
display4 ,i must therefore select from  
its  inexhaustible stores those topics  
which are most striking in their        
results1 and most popular in their      
details4    ,one of the most ancient    
feats of magic was the art of breathing 
flame1--an art which even now excites   
the astonishment of the vulgar4  ,during
 the insurrection of the slaves in      
,sicily1 in the second century  before  
,christ1 a ,syrian named ,eunus acquired
 by his knowledge the rank  of their    
leader4 ,in order to establish his      
influence over their minds1  he         
pretended to possess miraculous power4  
,when he wished to inspire his          
followers with courage1 he breathed     
flames or sparks among them from  his   

mouth1 at the same time that he was     
rousing them by his eloquence4  ,st4    
,jerome informs us that the ,rabbi      
,barchochebas1 who headed the ,jews  in 
their last revolt against ,hadrian1 made
 them believe that he was the  ,messiah1
 by vomiting flames from his mouth2 and 
at a later period1 the  ,emperor        
,constantius was thrown into a state of 
alarm when ,valentinian  informed him   
that he had seen one of the body-guards 
breathing out  fire and flames4 ,we are 
not acquainted with the exact methods by
 which  these effects were produced2 but
 ,florus informs us that ,eunus filled  
a perforated nut-shell with sulphur and 
fire1 and having concealed it  in his   
mouth1 he breathed gently through it    
while he was speaking4  ,this art is    
performed more simply by the modern     
juggler4 ,having rolled  together some  
flax or hemp1 so as to form a ball the  
size of a walnut1  he sets it on fire1  
and allows it to burn till it is nearly 
consumed3  he then rolls round it while 

burning some additional flax1 and by    
these  means the fire may be retained in
 it for a considerable time4 ,at the    
commencement of his exhibition he       
introduces the ball into his mouth1  and
 while he breathes through it the fire  
is revived1 and a number  of burning    
sparks are projected from his mouth4    
,these sparks are too  feeble to do any 
harm1 provided he inhales the air       
through his nostrils4    ,the kindred   
art of walking on burning coals or      
red-hot iron remounts to  the same      
antiquity4 ,the priestesses of ,diana at
 ,castabala in ,cappadocia  were        
accustomed1 according to ,strabo1 to    
walk over burning coals2 and  at the    
annual festival which was held in the   
temple of ,apollo on ,mount  ,soracte in
 ,etruria1 the ,hirpi marched over      
burning coals1 and on this  account they
 were exempted from military service1   
and received other  privileges from the 
,roman ,senate4 ,this power of resisting
 fire was  ascribed even by ,varro to   

the use of some liniment with which they
  anointed the soles of their feet4     
,of the same character was the art of   
holding red-hot iron in the hands  or   
between the teeth1 and of plunging the  
hands into boiling water or  melted     
lead4 ,about the close of the           
seventeenth century1 an ,englishman  of 
the name of ,richardson rendered himself
 famous by chewing burning  coals1      
pouring melted lead upon his tongue1 and
 swallowing melted  glass4 ,that these  
effects are produced partly by          
deception1 and partly  by a previous    
preparation of the parts subjected to   
the heat1 can  scarcely admit of a      
doubt4 ,the fusible metal1 composed of  
mercury1  tin1 and bismuth1 which melts 
at a low temperature1 might easily have 
been substituted in place of lead2 and  
fluids of easy ebullition may  have been
 used in place of boiling water4 ,a     
solution of spermaceti  or sulphuric    
ether1 tinged with alkanet root1 which  
becomes solid at  #ej of ,fahrenheit1   

and melts and boils with the heat of the
 hand1 is  supposed to be the substance 
which is used at ,naples when the dried 
blood of ,st4 ,januarius melts          
spontaneously1 and boils over the vessel
  which contains it4    ,but even when  
the fluid requires a high temperature to
 boil1 it may  have other properties1   
which enable us to plunge our hands into
 it  with impunity4 ,this is the case   
with boiling tar1 which boils at a      
temperature of #bbj1 even higher than   
that of water4 ,mr4 ,davenport  informs 
us1 that he saw one of the workmen in   
the ,royal ,dock-yard at  ,chatham      
immerse his naked hand in tar of that   
temperature4 ,he drew up  his           
coat-sleeves1 dipped in his hand and    
wrist1 bringing out fluid tar1  and     
pouring it off from his hand as from a  
ladle4 ,the tar remained in  complete   
contact with his skin1 and he wiped it  
off with tow4 ,convinced  that there was
 no deception in this experiment1 ,mr4  
,davenport immersed  the entire length  

of his fore-finger in the boiling       
cauldron1 and  moved it about a short   
time before the heat became             
inconvenient4 ,mr4  ,davenport ascribes 
this singular effect to the slowness    
with which  the tar communicates its    
heat1 which he conceives to arise from  
the  abundant volatile vapour which is  
evolved1 8carrying off rapidly  the     
caloric in a latent state1 and          
intervening between the tar and  the    
skin1 so as to prevent the more rapid   
communication of heat40  ,he conceives  
also1 that when the hand is withdrawn1  
and the hot tar  adhering to it1 the    
rapidity with which this vapour is      
evolved from  the surface exposed to the
 air cools it immediately4 ,the workmen 
informed ,mr4 ,davenport that1 if a     
person put his hand into the cauldron   
with his glove on1 he would be          
dreadfully burnt2 but this extraordinary
  result was not put to the test of     
observation4    ,but though the         
conjurors with fire may have availed    

themselves of  these singular properties
 of individual bodies1 yet the general  
secret  of their art consisted in       
rendering the skin of the exposed parts 
callous and insensible to heat1--an     
effect which may be produced by         
continually compressing or singeing them
 till the skin acquires a horny         
consistence4 ,a proof of this opinion is
 mentioned by ,beckmann1 who  assures   
us1 that in ,september1 #agfe1 when he  
visited the copper-works  at ,awestad1  
one of the workmen1 bribed by a little  
money to drink1  took some of the melted
 copper in his hand1 and1 after showing 
it to  the company1 threw it against a  
wall4 ,he then squeezed the fingers of  
his horny hand close to each other1 held
 it a few minutes under his  arm-pit1 to
 make it perspire1 as he said1 and      
taking it again out1 drew  it over a    
ladle filled with melted copper1 some of
 which he skimmed  off1 and moved his   
hand backwards and forwards very quickly
 by way of  ostentation4 ,during this   

performance1 ,m4 ,beckmann noticed a    
smell like  that of singed horn or      
leather1 though the hand of the workman 
was  not burned4 ,this callosity of the 
skin may be effected by frequently      
moistening it with dilute sulphuric     
acid4 ,some allege that the juices  of  
certain plants produce the same effect1 
while others recommend the  frequent    
rubbing of the skin with oil4 ,the      
receipt given by ,albertus  ,magnus for 
this purpose was of a different nature4 
,it consisted of a  non-conducting      
calcareous paste1 which was made to     
adhere to the skin  by the sap of the   
marsh-mallow1 the slimy seeds of the    
flea-bane1 and  the white of an egg4    
,as the ancients were acquainted with   
the incombustibility of asbestos  or    
amianthus1 and the art of weaving it    
into cloth1 it is highly  probable that 
it was employed in the performance of   
some of their  miracles1 and it is      
equally probable that it was            
subsequently used1  along with some of  

the processes already described1 in     
enabling the  victims of superstition to
 undergo without hazard the trial of    
ordeal  by fire4 ,in every country where
 this barbarous usage prevailed1 whether
  in the sanctuary of the ,christian    
idolater1 or in the pagan temple of  the
 ,bramin1 or under the wild orgies of   
the ,african savage1 ,providence  seems 
to have provided the means of meeting it
 with impunity4 ,in  ,catholic countries
 this exculpatory judgment was granted  
chiefly  to persons in weak health1 who 
were incapable of using arms1 and       
particularly to monks and ecclesiastics1
 who could not avail themselves  of the 
trial by single combat4 ,the fire ordeal
 was conducted in the  church under the 
inspection of the clergy3 mass was at   
the same time  celebrated1 and the iron 
and the victims were consecrated by the 
sprinkling of holy water4 ,the          
preparatory steps were also under the   
direction of the priests4 ,it was       
necessary that the accused should be    

placed three days and three nights under
 their care1 both before and  after the 
trial4 ,under the pretence of preventing
 the defendant from  preparing his hands
 by art1 and in order to ascertain the  
result of  the ordeal1 his hands were   
covered up and sealed during the three  
days  which preceded and followed the   
fiery application2 and it has been      
plausibly conjectured by ,beckmann1 that
 during the first three days the        
preventive was applied to those whom    
they wished to acquit1 and that  the    
last three days were requisite to bring 
back the hands to their  natural        
condition4 ,in these and other cases1   
the accused could not  have availed     
himself directly of the use of asbestos 
gloves1 unless we  could suppose them so
 made as to imitate the human skin at a 
distance2  but the fibres of that       
mineral may have been imbedded in a     
paste which  applied itself readily to  
all the elevations and depressions of   
the  skin4    ,in our own times the art 

of defending the hands and face1 and    
indeed  the whole body1 from the action 
of heated iron and intense fire1 has    
been applied to the nobler purpose of   
saving human life1 and rescuing         
property from the flames4 ,the revival  
and the improvement of this art  we owe 
to the benevolence and the ingenuity of 
the ,chevalier ,aldini of  ,milan1 who  
has travelled through all ,europe to    
present this valuable  gift to his      
species4 ,sir ,h4 ,davy had long ago    
shown that a safety  lamp for           
illuminating mines1 containing          
inflammable air1 might be  constructed  
of wire-gauze alone1 which prevented the
 flame within1  however large or        
intense1 from setting fire to the       
inflammable air  without4 ,this valuable
 property1 which has been long in       
practical use1  he ascribed to the      
conducting and radiating power of the   
wire-gauze1  which carried off the heat 
of the flame1 and deprived it of its    
power4  ,the ,chevalier ,aldini         

conceived the idea of applying the same 
material1  in combination with other    
badly conducting substances1 as a       
protection  against fire4 ,the          
incombustible pieces of dress which he  
uses for the  body1 arms1 and legs1 are 
formed out of strong cloth1 which has   
been  steeped in a solution of alum1    
while those for the head1 hands1 and    
feet1 are made of cloth of asbestos or  
amianthus4 ,the head-dress is  a large  
cap which envelops the whole head down  
to the neck1 having  suitable           
perforations for the eyes1 nose1 and    
mouth4 ,the stockings and  cap are      
single1 but the gloves are made of      
double amianthus cloth1 to  enable the  
fireman to take into his hand burning or
 red hot bodies4 ,the  piece of ancient 
asbestos cloth preserved in the ,vatican
 was formed1  we believe1 by mixing the 
asbestos with other fibrous substances2 
but ,m4 ,aldini has executed a piece of 
nearly the same size1 nine  feet five   
inches long and five feet three inches  

wide1 which is much  stronger than the  
ancient piece1 and possesses superior   
qualities1  in consequence of having    
been woven without the introduction of  
any  foreign substance4 ,in this        
manufacture the fibres are prevented    
from  breaking by the action of steam1  
the cloth is made loose in its fabric1  
and the threads are about the fiftieth  
of an inch in diameter4    ,the metallic
 dress which is superadded to these     
means of defence  consists of five      
principal pieces1 viz4 a casque or cap1 
with a mask  large enough to leave a    
proper space between it and the asbestos
 cap2 a  cuirass with its brassets2 a   
piece of armour for the trunk and       
thighs2  a pair of boots of double      
wire-gauze2 and an oval shield #e feet  
long  by #b wide1 made by stretching the
 wire-gauze over a slender frame of     
iron4 ,all these pieces are made of iron
 wire-gauze1 having the interval        
between its threads the twenty-fifth    
part of an inch4    ,in order to prove  

the efficacy of this apparatus1 and     
inspire the  firemen with confidence in 
its protection1 he showed them that a   
finger  first enveloped in asbestos1 and
 then in a double case of wire-gauze1   
might be held a long time in the flame  
of a spirit-lamp or candle  before the  
heat became inconvenient4 ,a fireman    
having his hand within  a double        
asbestos glove1 and its palm protected  
by a piece of asbestos  cloth1 seized   
with impunity a large piece of red-hot  
iron1 carried it  deliberately to the   
distance of #aej feet1 inflamed straw   
with it1 and  brought it back again to  
the furnace4 ,on other occasions the    
fireman  handled blazing wood and       
burning substances1 and walked during   
five  minutes upon an iron grating      
placed over flaming fagots4    ,in order
 to show how the head1 eyes1 and lungs  
are protected1 the  fireman put on the  
asbestos and wire-gauze cap1 and the    
cuirass1 and  held the shield before his
 breast4 ,a fire of shavings was then   

lighted1  and kept burning in a large   
raised chafing-dish2 the fireman plunged
  his head into the middle of the flames
 with his face to the fuel1 and  in that
 position went several times round the  
chafing-dish for a period  longer than a
 minute4 ,in a subsequent trial1 at     
,paris1 a fireman placed  his head in   
the middle of a large brazier filled    
with flaming hay and  wood1 as in ,fig4 
#gg1 and resisted the action of the fire
 during five or  six minutes1 and even  
ten minutes4    ,illustration3 ,fig4    
#gg4    ,in the experiments which were  
made at ,paris in the presence of a     
committee of the ,academy of ,sciences1 
two parallel rows of straw and          
brushwood1 supported by iron wires1 were
 formed at the distance of  three feet  
from each other1 and extended thirty    
feet in length4 ,when  this combustible 
mass was set on fire1 it was necessary  
to stand at  the distance of eight or   
ten yards to avoid the heat4 ,the flames
 from  both the rows seemed to fill up  

the whole space between them1 and rose  
to the height of nine or ten feet4 ,at  
this moment six firemen1 clothed  in the
 incombustible dresses1 and marching at 
a slow pace behind each  other1         
repeatedly passed through the whole     
length between the two rows  of flame1  
which were constantly fed with          
additional combustibles4  ,one of the   
firemen carried on his back a child     
eight years old1 in a  wicker-basket    
covered with metallic gauze1 and the    
child had no other  dress than a cap    
made of amianthine cloth4    ,in        
,february1 #ahbi1 a still more striking 
experiment was made in the  yard of the 
barracks of ,st4 ,gervais4 ,two towers  
were erected two  stories high1 and were
 surrounded with heaps of inflamed      
materials1  consisting of fagots and    
straw4 ,the firemen braved the danger   
with  impunity4 ,in opposition to the   
advice of ,m4 ,aldini1 one of them1 with
  the basket and child1 rushed into a   
narrow place1 where the flames were     

raging eight yards high4 ,the violence  
of the fire was so great that he  could 
not be seen1 while a thick black smoke  
spread around1 throwing  out a heat     
which was unsupportable by the          
spectators4 ,the fireman  remained so   
long invisible that serious doubts were 
entertained of his  safety4 ,he at      
length1 however1 issued from the fiery  
gulf uninjured1  and proud of having    
succeeded in braving so great a danger4 
,it is a remarkable result of these     
experiments1 that the firemen  are able 
to breathe without difficulty in the    
middle of the flames4  ,this effect is  
owing not only to the heat being        
intercepted by the  wire-gauze as it    
passes to the lungs1 in consequence of  
which its  temperature becomes          
supportable1 but also to the singular   
power which  the body possesses of      
resisting great heats1 and of breathing 
air of  high temperatures4    ,a series 
of curious experiments were made on this
 subject by ,m4 ,tillet  in ,france1 and

 by ,dr4 ,fordyce and ,sir ,charles     
,blagden in ,england4 ,sir  ,joseph     
,banks1 ,dr4 ,solander1 and ,sir        
,charles ,blagden entered a room  in    
which the air had a temperature of #aih 
,fahr41 and remained ten  minutes2 but  
as the thermometer sank very rapidly1   
they resolved to  enter the room singly4
 ,dr4 ,solander went in alone1 and found
 the heat  #baj1 and ,sir ,joseph       
entered when the heat was #baa4 ,though 
exposed  to such an elevated            
temperature1 their bodies preserved     
their natural  degree of heat4 ,whenever
 they breathed upon a thermometer it    
sank  several degrees3 every expiration1
 particularly if strongly made1 gave  a 
pleasant impression of coolness to their
 nostrils1 and their cold  breath cooled
 their fingers whenever it reached them4
 ,on touching his  side1 ,sir ,charles  
,blagden found it cold like a corpse1   
and yet the  heat of his body under his 
tongue was #ih4 ,hence they concluded   
that  the human body possesses the power

 of destroying a certain degree  of heat
 when communicated with a certain degree
 of quickness4 ,this  power1 however1   
varies greatly in different media4 ,the 
same person  who experienced no         
inconvenience from air heated to #baa1  
could just  bear rectified spirits of   
wine at #acj1 cooling oil at #abi1      
cooling  water at #abc1 and cooling     
quicksilver at #aag4 ,a familiar        
instance of  this occurred in the heated
 room4 ,all the pieces of metal there1  
even  their watch-chains1 felt so hot   
that they could scarcely bear to touch  
them for a moment1 while the air from   
which the metal had derived all  its    
heat was only unpleasant4 ,messrs4      
,duhamel and ,tillet observed1  at      
,rochefoucault in ,france1 that the     
girls who were accustomed to  attend    
ovens in a bakehouse were capable of    
enduring for ten minutes a  temperature 
of #bgj4    ,the same gentlemen who     
performed the experiments above         
described  ventured to expose themselves

 to still higher temperatures4 ,sir     
,charles  ,blagden went into a room     
where the heat was #a or #b above #bfj1 
and  remained eight minutes in this     
situation1 frequently walking about  to 
all the different parts of the room1 but
 standing still most of  the time in the
 coolest spot1 where the heat was above 
#bdj4 ,the air1  though very hot1 gave  
no pain1 and ,sir ,charles and all the  
other  gentlemen were of opinion that   
they could support a much greater heat4 
,during seven minutes ,sir ,c4          
,blagden's breathing continued perfectly
  good1 but after that time he felt an  
oppression in his lungs1 with  a sense  
of anxiety1 which induced him to leave  
the room4 ,his pulse  was then #add1    
double its ordinary quickness4 ,in order
 to prove that  there was no mistake    
respecting the degree of heat indicated 
by the  thermometer1 and that the air   
which they breathed was capable of      
producing all the well-known effects of 
such a heat on inanimate  matter1 they  

placed some eggs and a beef-steak upon a
 tin frame near  the thermometer1 but   
more distant from the furnace than from 
the wall  of the room4 ,in the space of 
twenty minutes the eggs were roasted    
quite  hard1 and in forty-seven minutes 
the steak was not only dressed1 but     
almost dry4 ,another beef-steak1        
similarly placed1 was rather overdone   
in thirty-three minutes4 ,in the        
evening1 when the heat was still more   
elevated1 a third beef-steak was laid in
 the same place1 and as they  had       
noticed that the effect of the hot air  
was greatly increased by  putting it in 
motion1 they blew upon the steak with a 
pair of bellows1  and thus hastened the 
dressing of it to such a degree that the
  greatest portion of it was found to be
 pretty well done in thirteen  minutes4 
,our distinguished countryman1 ,sir ,f4 
,chantrey1 has very recently  exposed   
himself to a temperature still higher   
than any which we have  mentioned4 ,the 
furnace which he employs for drying his 

moulds is about  #ad feet long1 #ab feet
 high1 and #ab feet broad4 ,when it is  
raised to  its highest temperature1 with
 the doors closed1 the thermometer      
stands  at #cej1 and the iron floor is  
red hot4 ,the workmen often enter it  at
 a temperature of #cdj1 walking over the
 iron floor with wooden  clogs1 which   
are of course charred on the surface4   
,on one occasion  ,sir ,f4 ,chantrey1   
accompanied by five or six of his       
friends1 entered  the furnace1 and1     
after remaining two minutes1 they       
brought out a  thermometer which stood  
at #cbj4 ,some of the party experienced 
sharp  pains in the tips of their ears1 
and in the septum of the nose1 while    
others felt a pain in their eyes4       
,,letter ,,xiii4     ,spontaneous       
combustion--,in the absorption of air by
 powdered   charcoal--and of hydrogen by
 spongy platinum--,dobereiner's         
lamp--,spontaneous combustion in the    
bowels of the earth--,burning           
cliffs--,burning soil--,combustion      

without flame--,spontaneous combustion  
of human beings--,countess              
,zangari--,grace ,pett--,natural        
fire-temples   of the                   
,guebres--,spontaneous fires in the     
,caspian ,sea--,springs of   inflammable
 gas near ,glasgow--,natural light-house
 of ,maracaybo--,new   elastic fluids in
 their cavities--of gems--,chemical     
operation going   on in their           
cavities--,explosions produced in them  
by heat--,remarkable   changes of colour
 from chemical causes--,effects of the  
nitrous oxide   of ,paradise gas when   
breathed--,remarkable cases             
described--,conclusion4      ,among the 
wonderful phenomena which chemistry     
presents to us1 there  are few more     
remarkable than those of spontaneous    
combustion1 in which  bodies both       
animate and inanimate emit flames1 and  
are sometimes  entirely consumed by     
internal fire4 ,one of the commonest    
experiments  in chemistry is that of    
producing inflammation by mixing two    

fluids  perfectly cold4 ,becker1 we     
believe1 was the first person who       
discovered  that this singular effect   
was produced by mixing oil of vitriol   
with  oil of turpentine4 ,borrichios    
showed that aqua-fortis produced the    
same effect as oil of vitriol4          
,tournefort proved that spirit of nitre 
and oil of sassafras took fire when     
mixed2 and ,homberg discovered that  the
 same property was possessed by many    
volatile oils when mixed with  spirit of
 nitre4    ,every person is familiar    
with the phenomena of heat and          
combustion  produced by fermentation4   
,ricks of hay and stacks of corn have   
been  frequently consumed by the heat   
generated during the fermentation       
produced from moisture2 and             
gunpowder-magazines1 barns1 and         
paper-mills  have been often burned by  
the fermentation of the materials which 
they  contained4 ,galen informs us that 
the dung of a pigeon is sufficient  to  
set fire to a house2 and he assures us  

that he has often seen it  take fire    
when it had become rotten4 ,casati      
likewise relates1 on good  authority1   
that the fire which consumed the great  
church of ,pisa was  occasioned by the  
dung of pigeons that had for centuries  
built their  nests under its roof4      
,among the substances subject to        
spontaneous combustion1 pulverized  or  
finely-powdered charcoal is one of the  
most remarkable4 ,during  the last      
thirty years no fewer than four cases of
 the spontaneous  inflammation of       
powdered charcoal have taken place in   
,france4 ,when  charcoal is triturated  
in tuns with bronze bruisers1 it is     
reduced  into the state of the finest   
powder4 ,in this condition it has the   
appearance of an unctuous fluid1 and it 
occupies a space three times  less than 
it does in rods of about six inches     
long4 ,in this state of  extreme        
division it absorbs air much more       
readily than it does when  in rods4     
,this absorption1 which is so slow as to

 require several days  for its          
completion1 is accompanied with a       
disengagement of heat which  rises from 
#cdj to #cfj nearly of ,fahrenheit1 and 
which is the true  cause of the         
spontaneous inflammation4 ,the          
inflammation commences near  the centre 
of the mass1 at the depth of five or six
 inches beneath  its surface1 and at    
this spot the temperature is always     
higher than  at any other4 ,black       
charcoal1 strongly distilled1 heats and 
inflames  more easily than the orange1  
or that which is little distilled1 or   
than the charcoal made in boilers4 ,the 
most inflammable charcoal  must have a  
mass of at least #fflbs4 avoirdupois1 in
 order that it  may be susceptible of   
spontaneous inflammation4 ,with the     
other less  inflammable varieties1 the  
inflammation takes place only in larger 
masses4    ,the inflammation of powdered
 charcoal is more active in proportion  
to the shortness of the interval between
 its carbonization and  trituration4    

,the free admission of air to the       
surface of the charcoal  is also        
indispensable to its spontaneous        
combustion4    ,colonel ,aubert1 to whom
 we owe these interesting results1      
likewise  found that when sulphur and   
saltpetre are added to the charcoal1 it 
loses its power of inflaming            
spontaneously4 ,but as there is still an
  absorption of air and a generation of 
heat1 he is of opinion that it  would   
not be prudent to leave these mixtures  
in too large masses after               
trituration4#cd     #cd ,see ,edinburgh 
,journal of ,science1 ,new ,series1 ,no4
 viii4 p4 #bgd4    ,a species of        
spontaneous combustion1 perfectly       
analogous to that now  described1 but   
produced almost instantaneously1 was    
discovered by  ,professor ,dobereiner of
 ,jena in #ahbd4 ,he found that when a  
jet of  hydrogen gas was thrown upon    
recently prepared spongy platinum1 the  
metal became almost instantly red hot1  
and set fire to gas4 ,in this  case the 

minutely divided platinum acted upon the
 hydrogen gas in the  same manner as the
 minutely divided charcoal acted upon   
common air4  ,heat and combustion were  
produced by the absorption of both      
gases1  though in the one case the      
effect was instantaneous1 and in the    
other  was the result of a prolonged    
absorption4    ,illustration3 ,fig4 #gh4
    ,this beautiful property of spongy  
platinum was happily applied to the     
construction of lamps for producing an  
instantaneous light4 ,the form  given to
 the lamp by ,mr4 ,garden of ,london is 
shown in the annexed  figure1 where ,,ab
 is a globe of glass1 fitting tightly   
into another  glass globe ,,cd by a     
ground shoulder m n4 ,the globe ,,ab    
terminates  in a hollow tapering neck m 
n o p1 on the lower end of which is     
placed a small cylinder of zinc o p4 ,a 
brass tube a b c1 is  fitted at a into  
the neck of the globe ,,cd1 and through 
this tube1  which is furnished with a   
stop-cock d1 the gas can escape at the  

small aperture c4 ,a brass pin c f1     
carrying a brass box ,p1 is made  to    
slide through a hole h1 so that the     
brass box ,p1 in which the  spongy      
platinum is placed1 can be set at any   
required distance from  the aperture c4 
,if sulphuric acid1 diluted with an     
equal quantity of  water1 is now poured 
into the vessel ,,ab by its mouth at ,s1
 now closed  with a stopper1 the fluid  
will descend through the tube m n o p1  
and  if the cock d is shut1 it will     
compress the air contained in ,,cd4 ,the
  dilute acid thus introduced into ,,cd 
will act upon the ring of zinc o  p1 and
 generate hydrogen gas1 which1 after the
 atmospheric air in ,,cd  is let off1   
will gradually fill the vessel ,,cd1 the
 diluted acid being  forced up the tube 
o p m n1 into the glass globe ,,ab4 ,the
 ring of zinc  o p floats on a piece of 
cork1 so that when ,,cd is full of      
hydrogen1  the diluted acid does not    
touch the zinc1 and consequently is     
prevented  from producing any more gas4 

,the instant1 however1 that any gas is  
let  off at c1 the pressure of the fluid
 in the globe ,,ab1 and tube m n o  p1  
overcomes the elasticity of the         
remaining gas in ,,cd1 and forces the   
diluted acid up to the zinc o p1 so as  
to enable it to produce more  gas to    
supply what has been used4    ,the lamp 
being supplied with hydrogen in the     
manner now described1  it is used in the
 following manner4 ,the spongy platinum 
in ,p being  brought near c1 the cock d 
is turned1 and the gas is thrown upon   
the platinum4 ,an intense heat is       
immediately produced1 the platinum      
becomes red-hot1 and the hydrogen       
inflames4 ,a taper is then lighted at   
the flame1 and the cock d is shut4      
,professor ,cumming1 of ,cambridge1     
found it necessary to cover up the      
platinum with a cap after every         
experiment4 ,this ingenious chemist     
likewise found1 that1 with platinum     
foil the #i1jjjth part of an inch thick 
kept in a close tube1 the  hydrogen was 

inflamed2 but when the foil was only the
 #f1jjjth of an  inch thick1 it was     
necessary to raise it previously to a   
red heat4    ,spontaneous combustion is 
a phenomenon which occurs very          
frequently  and often to a great extent 
within the bowels of the earth4 ,the    
heat  by which it is occasioned is      
produced by the decomposition of mineral
  bodies and other causes4 ,this heat   
increases in intensity till it is       
capable of melting the solid materials  
which are exposed to it4 ,gases  and    
aqueous vapours of powerful elasticity  
are generated1 new fluids  of expansive 
energy imprisoned in cavities under     
great pressure are  set free1 and these 
tremendous agents1 acting under the     
repressing  forces of the superincumbent
 strata1 exhibit their power in         
desolating  earthquakes2 or1 forcing    
their way through the superficial crust 
of the  globe1 they waste their fury in 
volcanic eruptions4    ,when the        
phenomena of spontaneous combustion take

 place near the  surface of the earth1  
its effects are of a less dangerous     
character1  though they frequently give 
birth to permanent conflagrations1 which
 no  power can extinguish4 ,an example  
of this milder species of spontaneous   
combustion has been recently exhibited  
in the burning cliff at  ,weymouth2 and 
a still more interesting one exists at  
this moment near  the village of        
,bradley1 in ,staffordshire4 ,the earth 
is here on fire1  and this fire has     
continued for nearly sixty years1 and   
has resisted  every attempt that has    
been made to extinguish it4 ,this fire1 
which  has reduced many acres of land to
 a mere calx1 arises from a burning     
stratum of coal about four feet thick   
and eight or ten yards deep1 to  which  
the air has free access1 in consequence 
of the main coal having  been dug from  
beneath it4 ,the surface of the ground  
is sometimes  covered for many yards    
with such quantities of sulphur that it 
can be  easily gathered4 ,the calx has  

been found to be an excellent material  
for the roads1 and the workmen who      
collect it often find large beds of     
alum of an excellent quality4    ,a     
singular species of invisible           
combustion1 or of combustion without    
flame1 has been frequently noticed4 ,i  
have observed this phenomenon in  the   
small green wax tapers in common use4   
,when the flame is blown out1  the wick 
will continue red-hot for many hours2   
and if the taper were  regularly and    
carefully uncoiled1 and the room kept   
free from currents  of air1 the wick    
would burn on in this way till the whole
 of the taper  is consumed4 ,the same   
effects are not produced when the colour
 of the  wax is red4 ,in this experiment
 the wick1 after the flame is blown out1
  has sufficient heat to convert the wax
 into vapour1 and this vapour  being    
consumed without flame1 keeps the wick  
at its red heat4 ,a very  disagreeable  
vapour is produced during this imperfect
 combustion of the  wax4    ,prof4      

,dobereiner1 of ,jena1 observed that1   
when the alcohol in a spirit  of wine   
lamp was nearly exhausted1 the wick     
became carbonized1 and  though the flame
 disappeared1 the carbonized part of the
 wick became  red-hot1 and continued so 
while a drop of alcohol remained1       
provided  the air in the room was       
undisturbed4 ,on one occasion the wick  
continued  red-hot for twenty-four      
hours1 and a very disagreeable acid     
vapour was  formed4    ,illustration3   
,fig4 #gi4    ,on these principles      
depend the lamp without flame which was 
originally constructed by ,mr4 ,ellis4  
,it is shown in the annexed  figure1    
where ,,ab is the lamp1 and h a         
cylindrical coil of platinum  wire1 the 
hundredth part of an inch in diameter4  
,this spiral is so  placed that four or 
five of the twelve coils of which the   
cylinder  consists are upon the wick1   
and the other seven or eight above it4  
,if  the lamp is lighted1 and continues 
burning till the cylindrical coil  is   

red-hot1 then if the flame is blown out1
 the vapour which arises  from the      
alcohol will by its combustion keep the 
coils above the wick  red-hot1 and this 
red heat will in its turn keep up the   
vaporization  of the alcohol till the   
whole of the alcohol is consumed4 ,the  
heat of  the wire is always sufficient  
to kindle a piece of ,german fungus or  
saltpetre paper1 so that a sulphur match
 may at any time be lighted4  ,mr4 ,gill
 found that a wick composed of twelve   
threads of the cotton  yarn commonly    
used for lamps will require half an     
ounce of alcohol to  keep the wire      
red-hot for eight hours4 ,this lamp has 
been kept burning  for sixty hours2 but 
it can scarcely be recommended for a    
bed-room1 as  an acid vapour is         
disengaged during the burning of the    
alcohol4 ,when  perfumes are dissolved  
in the alcohol1 they are diffused       
through the  apartment during the slow  
combustion of the vapour4    ,a species 
of combustion without flame1 and        

analogous to that which  has been       
described1 is exhibited in the          
extraordinary phenomenon of  the        
spontaneous combustion of living bodies4
 ,that animal bodies are  liable to     
internal combustion1 is a fact which was
 well known to the  ancients4 ,many     
cases which have been adduced as        
examples of spontaneous  combustion are 
merely cases of individuals who were    
highly susceptible  of strong electrical
 excitation4 ,in one of these cases1    
however1 ,peter  ,bovisteau asserts1    
that the sparks of fire thus produced1  
reduced to  ashes the hair of a young   
man2 and ,john de ,viana informs us1    
that the  wife of ,dr4 ,freilas1        
physician to the ,cardinal de ,royas1   
,archbishop of  ,toledo1 emitted by     
perspiration an inflammable matter of   
such a nature1  that when the ribbon    
which she wore over her shift was taken 
from her1  and exposed to the cold air1 
it instantly took fire1 and shot forth  
like grains of gunpowder4 ,peter        

,borelli has recorded a fact of the very
  same kind respecting a peasant whose  
linen took fire1 whether it was  laid up
 in a box when wet1 or hung up in the   
open air4 ,the same author  speaks of a 
woman who1 when at the point of death1  
vomited flames2 and  ,thomas ,bartholin 
mentions this phenomenon as having often
 happened to  persons who were great    
drinkers of wine or brandy4 ,ezekiel de 
,castro  mentions the singular case of  
,alexandrinus ,megetius1 a physician1   
from  one of whose vertebr there issued 
a fire which scorched the eyes of  the  
beholders2 and ,krantzius relates1 that 
during the wars of ,godfrey  of         
,bouillon1 certain people of the        
territory of ,nevers were burning  with 
invisible fire1 and that some of them   
cut off a foot or a hand  where the     
burning began1 in order to arrest the   
calamity4 ,nor have  these effects been 
confined to man4 ,in the time of the    
,roman consuls  ,gracchus and           
,juventius1 a flame is said to have     

issued from the mouth  of a bull without
 doing any injury to the animal4    ,the
 reader will judge of the degree of     
credit which may belong to these        
narrations when he examines the effects 
of a similar kind which have  taken     
place in less fabulous ages1 and nearer 
our own times4 ,john ,henry  ,cohausen  
informs us that a ,polish gentleman in  
the time of the ,queen  ,bona ,sforza1  
having drunk two dishes of a liquor     
called brandy-wine1  vomited flames1 and
 was burned by them1 and ,thomas        
,bartholin#ce thus  describes a similar 
accident3 8,a poor woman at ,paris used 
to drink  spirit of wine plentifully for
 the space of three years1 so as to take
  nothing else4 ,her body contracted    
such a combustible disposition1 that    
one night1 when she lay down on a straw 
couch1 she was all burned  to ashes     
except her skull and the extremities of 
her fingers40 ,john  ,christ4 ,sturmius 
informs us1 in the ,german ,ephemerides1
 that in the  northern countries of     

,europe flames often evaporate from the 
stomachs  of those who are addicted to  
the drinking of strong liquors2 and he  
adds1 8that seventeen years before1     
three noblemen of ,courland drank by    
emulation strong liquors1 and two of    
them died scorched and suffocated  by a 
flame which issued from their stomachs40
     #ce ,acta ,medica et ,philosophica 
,hafniensia1 #afgc4    ,one of the most 
remarkable cases of spontaneous         
combustion is that  of the ,countess    
,cornelia ,zangari and ,bandi of        
,cesena1 which has been  minutely       
described by the ,reverend ,joseph      
,bianchini1 a prebend in the  city of   
,verona4 ,this lady1 who is in the      
sixty-second year of her age1  retired  
to bed in her usual health4 ,here she   
spent above three hours  in familiar    
conversation with her maid1 and in      
saying her prayers2 and  having at last 
fallen asleep1 the door of her chamber  
was shut4 ,as her  maid was not summoned
 at the usual hour1 she went into the   

bed-room  to wake her mistress2 but     
receiving no answer1 she opened the     
window1  and saw her corpse on the floor
 in the most dreadful condition4 ,at    
the distance of four feet from the bed  
there was a heap of ashes4 ,her  legs1  
with the stockings on1 remained         
untouched1 and the head1 half  burned1  
lay between them4 ,nearly all the rest  
of the body was reduced  to ashes4 ,the 
air in the room was charged with        
floating soot4 ,a small  oil lamp on the
 floor was covered with ashes1 but had  
no oil in it2 and  in two candlesticks1 
which stood upright upon a table1 the   
cotton wick  of both the candles was    
left1 and the tallow of both had        
disappeared4  ,the bed was not injured1 
and the blankets and sheets were raised 
on  one side1 as if a person had risen  
up from it4 ,from an examination  of all
 the circumstances of this case1 it has 
been generally supposed  that an        
internal combustion had taken place2    
that the lady had risen  from her bed to

 cool herself1 and that1 in her way to  
open the window1  the combustion had    
overpowered her1 and consumed her body  
by a process  in which no flame was     
produced which could set fire to the    
furniture  or the floor4 ,the ,marquis  
,scipio ,maffei was informed by an      
,italian  nobleman who passed through   
,cesena a few days after this event1    
that  he heard it stated in that town1  
that the ,countess ,zangari was in  the 
habit1 when she felt indisposed1 of     
washing all her body with  camphorated  
spirit of wine4    ,so recently as      
#agdd1 a similar example of spontaneous 
combustion  occurred in our own country1
 at ,ipswich4 ,a fisherman's wife1 of   
the  name of ,grace ,pett1 of the parish
 of ,st4 ,clement's1 had been in the    
habit for several years of going down   
stairs every night1 after she was  half 
undressed1 to smoke a pipe4 ,she did    
this on the evening of the #ith  of     
,april1 #agdd4 ,her daughter1 who lay in
 the same bed with her1 had  fallen     

asleep1 and did not miss her mother till
 she awaked early in  the morning4 ,upon
 dressing herself1 and going down       
stairs1 she found  her mother's body    
lying on the right side1 with her head  
against the  grate1 and extended over   
the hearth1 with her legs on the deal   
floor1  and appearing like a block of   
wood burning with a glowing fire without
  flame4 ,upon quenching the fire with  
two bowls of water1 the neighbours1     
whom the cries of the daughter had      
brought in1 were almost stifled with    
the smell4 ,the trunk of the unfortunate
 woman was almost burned to  ashes1 and 
appeared like a heap of charcoal covered
 with white ashes4  ,the head1 arms1    
legs1 and thighs1 were also much burned4
 ,there was no  fire whatever in the    
grate1 and the candle was burned out in 
the socket  of the candlestick1 which   
stood by her4 ,the clothes of a child on
 one  side of her1 and a paper screen on
 the other1 were untouched3 and the     
deal floor was neither singed nor       

discoloured4 ,it was said that the      
woman had drunk plentifully of gin      
overnight in welcoming a daughter  who  
had recently returned from ,gibraltar4  
,among the phenomena of the natural     
world which are related to those  of    
spontaneous combustion1 are what have   
been called the natural  fire-temples of
 the ,guebres1 and the igneous phenomena
 which are  seen in their vicinity4 ,the
 ancient sect of the ,guebres or        
,parsees1  distinguished from all other 
sects as the worshippers of fire1  had  
their origin in ,persia2 but1 being     
scattered by persecution1  they sought  
an asylum on the shores of ,india4      
,those who refused  to expatriate       
themselves continued to inhabit the     
shores of the  ,caspian ,sea1 and the   
cities of ,ispahan1 ,yezd1 and ,kerman4 
,their great  fire-temple1 called       
,attush ,kudda1 stands in the vicinity  
of ,badku1  one of the largest and most 
commodious ports on the ,caspian4 ,in   
the  neighbourhood of this town the     

earth is impregnated with naphtha1 an   
inflammable mineral oil2 and the        
inhabitants have no other fuel1 and no  
other light1 but what is derived from   
this substance4    ,the remains of the  
ancient fire-temples of the ,guebres are
 still  visible about ten miles to the  
north-east of the town4 ,the temple in  
which the deity is worshipped under the 
form of fire1 is a space about  thirty  
yards square1 surrounded with a low     
wall1 and containing many  apartments4  
,in each of these a small volcano of    
sulphureous fire issues  from the ground
 through a furnace or funnel in the     
shape of a ,hindoo  altar4 ,on closing  
the funnel1 the fire is instantly       
extinguished2  and by placing the ear at
 the aperture1 a hollow sound is heard1 
accompanied with a strong current of    
cold air1 which may be lighted  at      
pleasure by holding to it any burning   
substance4 ,the flame is of a  pale1    
clear colour1 without any perceptible   
smoke1 and emits a highly  sulphureous  

vapour1 which impedes respiration1      
unless when the mouth  is kept beneath  
the level of the furnace4 ,this action  
on the lungs  gives the ,guebres a wan  
and emaciated appearance1 and oppresses 
them  with a hectic cough1 which        
strangers also feel while breathing this
  insalubrious atmosphere4    ,for about
 two miles in circumference1 round the  
principal fire1 the  whole ground1 when 
scraped to the depth of two or three    
inches1 has  the singular property of   
being inflamed by a burning coal4 ,in   
this  case1 however1 it does not        
communicate fire to the adjacent ground3
 but  if the earth is dug up with a     
spade1 and a torch brought near it1 an  
extensive but instantaneous             
conflagration takes place1 in which     
houses  have often been destroyed1 and  
the lives of the people exposed to      
imminent danger4    ,when the sky is    
clear and the weather serene1 the       
springs in their  ebullition do not rise
 higher than two or three feet2 but in  

gloomy  weather1 and during the         
prevalence of stormy clouds1 the springs
 are  in a state of the greatest        
ebullition1 and the naphtha1 which often
  takes fire spontaneously at the       
earth's surface1 flows burning in great 
quantities to the sea1 which is         
frequently covered with it1 in a state  
of flame1 to the distance of several    
leagues from the shore4    ,besides the 
fires in the temple1 there is a large   
one which springs  from a natural cliff 
in an open situation1 and which         
continually burns4  ,the general space  
in which this volcanic fire is most     
abundant is  somewhat less than a mile  
in circuit4 ,it forms a low flat hill1  
sloping  to the sea1 the soil of which  
is a sandy earth1 mixed with stones4    
,mr4  ,forster did not observe any      
violent eruption of flame in the country
  around the ,attush ,kudda2 but        
,kinneir informs us1 that the whole     
country  round ,badku has at times the  
appearance of being enveloped in flames4

  8,it often seems10 he adds1 8as if the
 fire rolled down from the  mountains in
 large masses1 and with incredible      
velocity2 and during the  clear         
moonshine nights of ,november and       
,december1 a bright blue light is       
observed at times to cover the whole    
western range4 ,the fire does not       
consume2 and if a person finds himself  
in the middle of it1 no warmth  is      
felt40    ,the inhabitants apply these  
natural fires to domestic purposes1 by  
sinking a hollow cane or merely a tube  
of paper1 about two inches in  the      
ground1 and by blowing upon a burning   
coal held near the orifice  of the tube1
 there issues a slight flame1 which     
neither burns the cane  nor the paper4  
,by means of these canes or paper tubes1
 from which the  fire issues1 the       
inhabitants boil the water in their     
coffee-urns1 and  even cook different   
articles of food4 ,the flame is put out 
by merely  plugging up the orifice4 ,the
 same tubes are employed for            

illuminating  houses that are not paved4
 ,the smell of naphtha is of course     
diffused  through the house3 but after  
any person is accustomed to it1 it      
ceases  to be disagreeable4 ,the        
inhabitants also employ this natural    
fire  in calcining lime4 ,the quantity  
of naphtha procured in the plain to  the
 south-east of ,badku is enormous4 ,it  
is drawn from wells1 some of  which     
yield from #a1jjj to #a1ejjlbs4 per day4
 ,as soon as these wells  are emptied1  
they fill again till the naphtha rises  
to its original  level4#cf     #cf ,see 
,forster's ,travels1 and ,kinneir's     
,geog4 ,memoir4    ,inflammable gases   
issuing from the earth have been used   
both in  the old and the new world for  
domestic purposes4 ,in the salt mine  of
 ,gottesgabe1 at ,rheims1 in the county 
of ,fecklenburg1 there is a  pit called 
the ,pit of the ,wind1 from which a     
constant current of  inflammable gas has
 issued for sixty years4 ,m4 ,roeder1   
the inspector of  the mines1 has used   

this gas for two years1 not only as a   
light1 but  for all the purposes of     
domestic economy4 ,in the pits which are
 not  worked1 he collects the gas1 and  
conveys it in tubes to his house4 ,it   
burns with a white and brilliant flame1 
has a density of about ,o4#ff1  and     
contains traces of carbonic acid gas and
 sulphuretted hydrogen4#cg     #cg      
,edinburgh ,journal of ,science1 ,no4   
xv41 p4 #ahc4    ,near the village of   
,fredonia1 in ,north ,america1 on the   
shores of  ,lake ,erie1 are a number of 
burning springs1 as they are called4    
,the  inflammable gas which issues from 
these springs is conveyed in pipes  to  
the village1 which is actually lighted  
by them4#ch     #ch ,edinburgh ,journal 
of ,science1 ,no4 xv41 p4 #ahc4    ,in  
the year #ahbh a copious spring of      
inflammable gas was discovered in       
,scotland1 in the bed of a rivulet which
 crosses the north road between         
,glasgow and ,edinburgh1 a little to the
 east of the seventh mile-stone  from   

,glasgow1 and only a few hundred yards  
from the house of ,bedlay4  ,the gas is 
said to issue for more than half a mile 
along the banks of  the rivulet4 ,dr4   
,thompson1 who has analysed the gas1 saw
 it issuing  only within a space about  
fifty yards in length1 and about half as
 much  in breadth4 8,the emission of gas
 was visible in a good many places      
along the declivity to the rivulet in   
the immediate neighbourhood of a  small 
farm-house4 ,the farmer had set the gas 
on fire in one place about  a yard      
square1 out of which a great many small 
jets were issuing4 ,it  had burnt       
without interruption during five weeks1 
and the soil 7which  was clay7 had      
assumed the appearance of pounded brick 
all around4    8,the flame was yellow   
and strong1 and resembled perfectly the 
appearance which carburetted hydrogen   
gas or fire-damp presents  when burnt in
 daylight4 ,but the greatest issue of   
gas was in the  rivulet itself1 distant 
about twenty yards from the place where 

the gas  was burning4 ,the rivulet1 when
 ,i visited the place1 was swollen and  
muddy1 so as to prevent its bottom from 
being seen4 ,but the gas issued  up     
through it in one place with great      
violence1 as if it had been in a  state 
of compression under the surface of the 
earth2 and the thickness  of the jet    
could not be less than two or three     
inches in diameter4 ,we  set the gas on 
fire as it issued through the water4 ,it
 burnt for some  time with a good deal  
of splendour2 but as the rivulet was    
swollen1  and rushing along with great  
impetuosity1 the regularity of the issue
  was necessarily disturbed1 and the gas
 was extinguished40 ,dr4 ,thompson      
found this gas to consist of two volumes
 of hydrogen gas1 and one  volume of    
vapour of carbon2 and as its specific   
gravity was #j4eee1  and as it issues in
 great abundance1 he remarks that it    
might be used  for filling air-balloons4
 8,were we assured10 he adds1 8that it  
would  continue to issue in as great    

abundance as at present1 it might be    
employed in lighting the streets of     
,glasgow40#ci     #ci ,edinburgh        
,journal of ,science1 ,no4 #a1 ,new     
,series1 p4 #ga-ge4    ,a very curious  
natural phenomenon1 called the ,lantern 
or ,natural  ,lighthouse of ,maracaybo1 
has been witnessed in ,south ,america4  
,a bright  light is seen every night on 
a mountainous and uninhabited spot on   
the  banks of the river ,catatumbo1 near
 its junction with the ,sulia4 ,it is   
easily distinguished at a greater       
distance than forty leagues1 and as  it 
is nearly in the meridian of the opening
 of the ,lake of ,maracaybo1  navigators
 are guided by it as by a light-house4  
,this phenomenon is  not only seen from 
the sea-coast1 but also from the        
interior of the  country--at ,merida1   
for example1 where ,m4 ,palacios        
observed it for  two years4 ,some       
persons have ascribed this remarkable   
phenomenon to  a thunder-storm1 or to   
electrical explosions which might take  

place  daily in a pass in the mountains2
 and it has even been asserted1  that   
the rolling of thunder is heard by those
 who approach the spot4  ,others suppose
 it to be an air-volcano1 like those on 
the ,caspian ,sea1  and that it is      
caused by asphaltic soils like those of 
,mena4 ,it is  more probable1 however1  
that it is a sort of carburetted        
hydrogen1 as  hydrogen gas is disengaged
 from the ground in the same            
district4#dj     #dj ,humboldt's        
,personal ,narrative1 vol4 iv4 p4 #bed1 
note4    ,grand as the chemical         
operations are which are going on in the
 great  laboratory of ,nature1 and      
alarming as their effects appear when   
they  are displayed in the terrors of   
the earthquake and the volcano1 yet     
they are not more wonderful to the      
philosopher than the minute though      
analogous operations which are often at 
work near our own persons1  unseen and  
unheeded4 ,it is not merely in the      
bowels of the earth  that highly        

expansive elements are imprisoned and   
restrained1 and  occasionally called    
into tremendous action by the excitation
 of heat  and other causes4 ,fluids and 
vapours of a similar character exist in 
the very gems and precious stones which 
science has contributed to  luxury and  
to the arts4    ,in examining with the  
microscope the structure of mineral     
bodies1 ,i  discovered in the interior  
of many of the gems thousands of        
cavities  of various forms and sizes4   
,some had the shape of hollow and       
regularly  formed crystals2 others      
possessed the most irregular outline1   
and  consisted of many cavities and     
branches united without order1 but  all 
communicating with each other4 ,these   
cavities sometimes occurred  singly1 but
 most frequently in groups forming      
strata of cavities1 at  one time        
perfectly flat and at another time      
curved4 ,several such  strata were often
 found in the same specimen1 sometimes  
parallel to  each other1 at other times 

inclined1 and forming all varieties of  
angles with the faces of the original   
crystal4    ,these cavities1 which      
occurred in sapphire1 chrysoberyl1      
topaz1  beryl1 quartz1 amethyst1        
peridot1 and other substances1 were     
sometimes sufficiently large to be      
distinctly seen by the naked eye1  but  
most frequently they were so small as to
 require a high magnifying  power to be 
well seen1 and often they were so       
exceedingly minute1 that  the highest   
magnifying powers were unable to exhibit
 their outline4    ,illustration3 ,fig4 
#hj4    ,the greater number of these    
cavities1 whether large or small1       
contained  two new fluids different from
 any hitherto known1 and possessing     
remarkable physical properties4 ,these  
two fluids are in general  perfectly    
transparent and colourless1 and they    
exist in the same cavity  in actual     
contact1 without mixing together in the 
slightest degree4 ,one  of them expands 
thirty times more than water1 and at a  

temperature of  about #hj of ,fahrenheit
 it expands so as to fill up the vacuity
 in the  cavity4 ,this will be          
understood from the annexed figure1     
where ,a ,b ,c ,d  is the cavity1 m n p 
o the highly expansible fluid in which  
at low  temperatures there is always a  
vacuity ,v1 like an air-bubble in common
  fluids1 and ,a m n1 ,c o p1 the second
 fluid occupying the angles ,a  and ,c4 
,when heat such as that of the hand is  
applied to the specimen1  the vacuity ,v
 gradually contracts in size1 and wholly
 vanishes at a  temperature of about    
#hj1 as shown in ,fig4 #ha4 ,the fluids 
are shaded1  as in these two figures1   
when they are seen by light reflected   
from  their surfaces4    ,illustration3 
,fig4 #ha4    ,illustration3 ,fig4 #hb4 
,when the cavities are large1 as in     
,fig4 #hb1 compared with the quantity   
of expansible fluid m n p o1 the heat   
converts the fluid into vapour1  an     
effect which is shown by the circular   
cavity ,v becoming larger and  larger   

till it fills the whole space m n o p4  
,when any of these cavities1 whether    
they are filled with fluid  or with     
vapour1 is allowed to cool1 the vacuity 
,v reappears at a  certain temperature4 
,in the fluid cavities the fluid        
contracts1 and  the small vacuity       
appears1 which grows larger and larger  
till it  resumes its original size4     
,when the cavities are large1 several   
small  vacuities make their appearance  
and gradually unite into one1 though    
they sometimes remain separate4 ,in deep
 cavities a very remarkable  phenomenon 
accompanies the reappearance of the     
vacuity4 ,at the instant  that the fluid
 has acquired the temperature at which  
it quits the  sides of the cavity1 an   
effervescence or rapid ebullition takes 
place1  and the transparent cavity is   
for a moment opaque1 with an infinite   
number of minute vacuities1 which       
instantly unite into one that goes  on  
enlarging as the temperature diminishes4
 ,in the vapour cavities the  vapour is 

reconverted by the cold into fluid1 and 
the vacuity ,v1 ,fig4  #hb1 gradually   
contracts till all the vapour has been  
precipitated4 ,it  is curious to        
observe1 when a great number of cavities
 are seen at once  in the field of the  
microscope1 that the vacuities all      
disappear and  reappear at the same     
instant4    ,while all these changes are
 going on in the expansive fluid1 the   
other denser fluid at ,a and ,c1 ,fig4  
#hj1 #ha1 remains unchanged either  in  
its form or magnitude4 ,on this account 
,i experienced considerable  difficulty 
in proving that it was a fluid4 ,the    
improbability of two  fluids existing in
 a transparent state in absolute        
contact1 without  mixing in the         
slightest degree1 or acting upon each   
other1 induced  many persons to whom ,i 
showed the phenomenon to consider the   
lines m  n1 o p1 ,fig4 #hj1 #ha1 as a   
partition in the cavity1 or the spaces  
,a  m n1 o p ,c1 either as filled with  
solid matter1 or as corners into  which 

the expanding fluid would not penetrate4
 ,the regular curvature1  however1 of   
the boundary line m n1 o p1 and other   
facts1 rendered  these suppositions     
untenable4    ,illustration3 ,fig4 #hc4 
,this difficulty was at last entirely   
removed by the discovery of a  cavity of
 the form shown in the annexed figure1  
where ,a1 ,b1 and ,c are  three portions
 of the expansible fluid separated by   
the interposition  of the second fluid  
,d ,e ,f4 ,the first portion ,a of the  
expansible fluid  had four vacuities ,v1
 ,x1 ,y1 ,z1 while the other two        
portions ,b1 ,c1 had  no vacuity4 ,in   
order to determine if the vacuities of  
the portions ,b1  ,c1 had passed over to
 ,a1 ,i took an accurate drawing of the 
appearances  at a temperature of #ej1 as
 shown in the figure1 and ,i watched the
  changes which took place in raising   
the temperature to #hc4 ,the portion  ,a
 gradually expanded itself till it      
filled up all the four vacuities  ,v1   
,x1 ,y1 and ,z1 but as the portions ,b1 

,c1 had no vacuities1 they could  expand
 themselves only by pushing back the    
supposed second fluid ,d ,e  ,f4 ,this  
effect actually took place4 ,the dense  
fluid quitted the side  of the cavity at
 ,f4 ,the two portions ,b1 ,c1 of the   
expansible fluid  instantly united1 and 
the dense fluid having retreated to the 
limit m  n o1 its other limit advanced  
to p q r1 thus proving it to  be a real 
fluid4 ,this experiment1 which ,i have  
often shown to others1  involves one of 
those rare combinations of circumstances
 which nature  sometimes presents to us 
in order to illustrate her most         
mysterious  operations4 ,had the        
portions ,b1 ,c1 been accompanied1 as is
 usual1 with  their vacuities1 the      
interposed fluid would have remained    
immoveable  between the two equal and   
opposite expansions2 but owing to the   
accidental circumstance of these        
vacuities having passed over into the   
other branch ,a of the cavity1 the fluid
 yielded to the difference of  the      

expansive forces between which it lay1  
and thus exhibited its fluid  character 
to the eye4    ,illustration3 ,fig4 #hd4
    ,when we examine these cavities     
narrowly1 we find that they are actually
  little laboratories1 in which chemical
 operations are constantly going  on1   
and beautiful optical phenomena         
continually displaying themselves4  ,let
 ,a ,b ,d ,c1 for example1 be the summit
 of a crystallized cavity in  topaz1 ,s 
,s representing the dense1 ,n ,n the    
expansible fluid1 bounded  by a circular
 line a b c d1 and ,v ,v the vacuity in 
the new fluid1  bounded by the circle e 
f g h4 ,if the face ,a ,b ,d ,c is      
placed under a  compound microscope1 so 
that light may be reflected at an angle 
less  than that of total reflexion1 and 
if the observer now looks through  the  
microscope1 the temperature of the room 
being #ej1 he will see the  second fluid
 ,s ,s shining with a very feeble       
reflected light1 the dense  fluid ,n ,n 
with a light perceptibly brighter1 and  

the vacuity ,v ,v with  a light of      
considerable brilliancy4 ,the boundaries
 a b c d1 e f g  h1 are marked by a     
well-defined outline1 and also by the   
concentric  coloured rings of thin      
plates produced by the extreme thinness 
of each  of the fluids at their edges4  
,if the temperature of the room is      
raised slowly to #eh1 a brown  spot will
 appear at x in the centre of the       
vacuity ,v ,v4 ,this spot  indicates the
 commencement of evaporation from the   
expansible fluid  below1 and arises from
 the partial precipitation of the vapour
 in the  roof of the cavity4 ,as the    
heat increases1 the brown spot enlarges 
and  becomes very dark4 ,it is then     
succeeded by a white spot and one or    
more coloured rings rise in the centre  
of the vacuity4 ,the vapour then  seems 
to form a drop1 and all the rings       
disappear by retiring to the  centre1   
but only to reappear with new lustre4   
,during the application  of heat1 the   
circle e f g h contracts and dilates    

like the pupil of  the eye4 ,when the   
vaporization is so feeble as to produce 
only a single  ring of one or two tints 
of the second order1 they vanish        
instantly  by breathing upon the        
crystal2 but when the slight heat of the
 breath  reaches the fluid1 it throws   
off fresh vapour1 and the rings again   
appear4    ,if a drop of ether is put   
upon the crystal when the rings are in a
  state of rapid play1 the cold produced
 by its evaporation causes them  to     
disappear1 till the temperature again   
rises4 ,when the temperature  is        
perfectly uniform1 the rings are        
stationary1 as shown between ,v and  ,v 
in fig4 #hd2 and it is interesting to   
observe the first ring produced  by the 
vapour swelling out to meet the first   
ring at the margin of  the fluid1 and   
sometimes coming so near it that the    
darkest parts of  both form a broad     
black band4 ,as the heat increases1 the 
vacuity ,v ,v  diminishes and disappears
 at #gi1 exhibiting many curious        

phenomena1  which we have not room to   
describe4    ,having fallen upon a      
method of opening the cavities1 and     
looking at the  fluids1 ,i was able to  
examine their properties with more      
attention4  ,when the expansible fluid  
first rises from the cavity upon the    
surface  of the topaz1 it neither       
remains still like the fixed oils1 nor  
disappears like evaporable fluids4      
,under the influence1 no doubt1 of  heat
 and moisture1 it is in a state of      
constant motion1 now spreading  itself  
on a thin plate over a large surface1   
and now contracting itself  into a      
deeper and much less extended drop4     
,these contractions and  extensions are 
marked by very beautiful optical        
phenomena4 ,when the  fluid has         
stretched itself out into a thin plate1 
it ceases to reflect  light like the    
thinnest part of the soap-bubble2 and   
when it is again  accumulated into a    
thicker drop1 it is covered with thin   
coloured rings  of thin plates4         

,after performing these motions1 which  
sometimes last for ten minutes1  the    
fluid suddenly disappears1 and leaves   
behind it a sort of granular  residue4  
,when examining this with a single      
microscope1 it again started  into a    
fluid state1 and extended and contracted
 itself as before4 ,this  was owing to  
the humidity of the hand which held the 
microscope1 and  ,i have been able to   
restore by moisture the fluidity of     
these grains  twenty days after they    
were formed from the fluid4 ,this       
portion was  shown to the ,rev4 ,dr4    
,fleming1 who remarked1 that1 had he    
observed  it accidentally1 he would have
 ascribed its apparent vitality to the  
movements of some of the animals of the 
genus ,planaria4    ,after the cavity   
has remained open for a day or two1 the 
dense fluid  comes out and quickly      
hardens into a transparent and yellowish
  resinous-looking substance1 which     
absorbs moisture1 though with less      
avidity than the other4 ,it is not      

volatilized by heat1 and is insoluble   
in water and alcohol4 ,it readily       
dissolves1 however1 with effervescence  
in the sulphuric1 nitric1 and muriatic  
acids4 ,the residue of the  expansible  
fluid is volatilized by heat1 and is    
dissolved1 but without  effervescence1  
in the above-mentioned acids4 ,the      
refractive power of  the dense fluid is 
about #a4bie1 and of the expansible one 
#a4aca4    ,the particles of the dense  
fluid have a very powerful attraction   
for  each other and for the mineral     
which contains them1 while those of  the
 expansible fluid have a very slight    
attraction for one another1  and also   
for the substance of the mineral4 ,hence
 the two fluids never  mix1 the dense   
fluid being attracted to the angles of  
angular cavities1  or filling the narrow
 necks by which two cavities            
communicate4 ,the  expansible fluid1 on 
the other hand1 fills the wide parts of 
the  cavities1 and in deep and round    
cavities it lies above the dense fluid4 

,when the dense fluid occupies the necks
 which join two cavities1  it performs  
the singular function of a fluid valve1 
opening and  shutting itself according  
to the expansions or contractions of the
  other fluid4 ,the fluid valves thus   
exhibited in action may suggest  some   
useful hints to the mechanic and the    
philosopher1 while they  afford ground  
of curious speculation in reference to  
the functions of  animal and vegetable  
bodies4 ,in the larger organizations of 
ordinary  animals1 where gravity must in
 general overpower1 or at least modify1 
the influence of capillary attraction1  
such a mechanism is neither  necessary  
nor appropriate2 but1 in the lesser     
functions of the same  animals1 and in  
almost all the microscopic structures of
 the lower  world1 where the force of   
gravity is entirely subjected to the    
more  powerful energy of capillary      
forces1 it is extremely probable that   
the  mechanism of immiscible fluids and 
fluid valves is generally adopted4      

,in several cavities in minerals ,i have
 found crystallized and other  bodies1  
sometimes transparent crystals1         
sometimes black spicular  crystals1 and 
sometimes black spheres1 all of which   
are moveable within  the cavity4 ,in    
some cavities the two new fluids occur  
in an indurated  state1 and others ,i   
have found to be lined with a powdery   
matter4 ,this  last class of cavities   
occurred in topaz1 and they were        
distinguished  from all others by the   
extraordinary beauty and symmetry of    
their  form4 ,one of these cavities     
represented a finely ornamented sceptre1
  and1 what is still more singular1 the 
different parts of which it is  composed
 lay in different planes4    ,when the  
gem which contains the highly expansive 
fluid is strong1 and  the cavity not    
near the surface1 heat may be applied to
 it without  danger2 but in the course  
of my experiments on this subject1 the  
mineral has often burst with a          
tremendous explosion1 and in one case   

wounded me on the brow4 ,an accident of 
the same kind occurred to a  gentleman  
who put a crystal into his mouth for the
 purpose of expanding  the fluid4 ,the  
specimen burst with great force and cut 
his mouth1 and  the fluid which was     
discharged from the cavity had a very   
disagreeable  taste4    ,in the gems    
which are peculiarly appropriated for   
female ornaments1  cavities containing  
the expansive fluid frequently occur1   
and if these  cavities should happen to 
be very near the surface or the edge of 
the  stone1 the fever heat of the body  
might be sufficient to burst them  with 
an alarming and even dangerous          
explosion4 ,i have never heard of  any  
such accident having occurred2 but if it
 has1 or if it ever shall  occur1 and if
 its naturally marvellous character     
shall be heightened by  any calamitous  
results1 the phenomena described in the 
preceding pages  will strip it of its   
wonder4    ,there are no facts in       
chemistry more interesting than those   

which  relate to the changes of colour1 
which are produced by the mixture of    
fluids1 and to the creation of brilliant
 colours by the combination  of bodies  
in which no colouring matter is visible4
 ,facts of this kind  are too common and
 too generally known to require to be   
noticed in a  work like this4 ,the art  
of producing such changes was known to  
some of  the early impostors1 who       
endeavoured to obtain a miraculous      
sanction  to their particular dogmas4   
,marcos1 the head of one of the sects   
that  wished to engraft paganism upon   
,christianity1 is said to have filled   
three transparent glasses with white    
wine1 and while he prayed1 the  wine in 
one of the glasses became red like      
blood1 that in another  became purple1  
and that in the third sky-blue4 ,such   
transformations  present no difficulty  
to the chemist4 ,there are several      
fluids1 such  as some of the coloured   
juices of plants1 which change their    
colour  rapidly and without any         

additional ingredient3 and in other     
cases1  there would be no difficulty in 
making additions to fluids which should 
produce a change of colour at any       
required instant4    ,a very remarkable 
experiment of an analogous nature has   
been publicly  exhibited in modern      
times4 ,professor ,beyruss1 who lived at
 the court  of the ,duke of ,brunswick1 
one day pronounced to his highness that 
the  dress which he wore should during  
dinner became red2 and the change       
actually took place1 to the astonishment
 of the prince and the rest  of his     
guests4 ,m4 ,vogel1 who has recorded    
this curious fact1 has not  divulged the
 secret of the ,german chemist2 but he  
observes1 that if  we pour lime-water   
into the juice of beet-root1 we shall   
obtain a  colourless liquid2 and that a 
piece of white cloth dipped in this     
liquid and dried rapidly1 will in a few 
hours become red by the mere  contact of
 air4 ,m4 ,vogel is also of opinion that
 this singular effect  would be         

accelerated in an apartment where       
champagne or other fluids  charged with 
carbonic acid are poured out in         
abundance4    ,among the wonders of     
chemistry we must number the remarkable 
effects  produced upon the human frame  
by the inhalation of paradise or        
intoxicating gas1 as it has been called4
 ,this gas is known to  chemists by the 
name of the nitrous oxide1 or the       
gaseous oxide of  azote1 or the         
protoxide of nitrogen4 ,it differs from 
atmospheric  air only in the proportion 
of its ingredients1 atmospheric air     
being composed of twenty-seven parts of 
oxygen1 and seventy-three  of nitrogen1 
while the nitrous oxide consists of     
thirty-seven parts  of oxygen1 and      
sixty-seven of nitrogen4 ,the most      
convenient way of  procuring the gas is 
to expose nitrate of ammonia in a       
tubulated  glass retort to the heat of  
an ,argand's lamp between #djj and #ejj 
of  ,fahrenheit4 ,the salt first melts2 
bubbles of gas begin to rise from  the  

mass1 and in a short time a brisk       
effervescence takes place1 which        
continues till all the salt has         
disappeared4 ,the products of this      
operation are the nitrous oxide and     
water1 the watery vapour being          
condensed in the neck of the retort1    
while the gas is received over  water4  
,the gas thus obtained is generally     
white1 and hence1 when it  is to be used
 for the purposes of respiration1 it    
should remain at  least an hour over    
water1 which will absorb the small      
quantity of acid  and of nitrate of     
ammonia which adhere to it4 ,a pound of 
the nitrate  of ammonia will in this way
 yield five cubic feet of gas fit for   
the  purpose of inhalation4    ,it was  
discovered by ,sir ,humphrey ,davy1 that
 this gas could be safely  taken into   
the lungs1 and that it was capable of   
supporting respiration  for a few       
minutes4 ,in making this experiment he  
was surprised to find  that it produced 
a singular species of intoxication1     

which he thus  describes3 8,i breathed10
 says he1 8three quarts of oxide from   
and into  a silk bag for more than half 
a minute without previously closing my  
nose or exhausting my lungs4 ,the first 
inspiration caused a slight  degree of  
giddiness4 ,this was succeeded by an    
uncommon sense of fulness  in the head1 
accompanied with loss of distinct       
sensation and voluntary  power1 a       
feeling analogous to that produced in   
the first stage of  intoxication1 but   
unattended by pleasurable sensations40  
,in describing  the effects of another  
experiment1 he says1 8,having previously
 closed  my nostrils and exhausted my   
lungs1 ,i breathed four quarts of       
nitrous  oxide from and into a silk bag4
 ,the first feelings were similar to    
those produced in the last experiment1  
but in less than half a minute1  the    
respiration being continued1 they       
diminished gradually1 and were          
succeeded by a highly pleasurable       
thrilling1 particularly in the  chest   

and the extremities4 ,the objects around
 me became dazzling1 and  my hearing    
more acute4 ,towards the last           
respiration the thrilling  increased1   
the sense of muscular power became      
greater1 and at last an  irresistible   
propensity to action was indulged in4 ,i
 recollect but  indistinctly what       
followed2 ,i knew that my motions were  
varied and  violent4 ,these effects very
 rarely ceased after respiration4 ,in   
ten  minutes ,i had recovered my natural
 state of mind4 ,the thrilling in the   
extremities continued longer than the   
other sensations4 ,this experiment  was 
made in the morning2 no languor or      
exhaustion was consequent1 my  feelings 
through the day were as usual1 and ,i   
passed the night in  undisturbed        
repose40    ,in giving an account of    
another experiment with this gas1 ,sir  
,humphrey  thus describes his feelings3 
8,immediately after my return from a    
long journey1 being fatigued1 ,i        
respired nine quarts of nitrous  oxide1 

having been precisely thirty-three days 
without breathing any4  ,the feelings   
were different from those ,i had        
experienced on former  experiments4     
,after the first six or seven           
respirations1 ,i gradually  began to    
lose the perception of external things1 
and a vivid and  intense recollection of
 some former experiments passed through 
my mind1  so that ,i called out1 #8,what
 an annoying concatenation of ideas6'0  
,another experiment made by the same    
distinguished chemist was attended  by  
still more remarkable results4 ,he was  
shut up in an airtight  breathing-box1  
having a capacity of about nine and a   
half cubic feet1  and he allowed himself
 to be habituated to the excitement of  
the gas1  which was gradually           
introduced4 ,after having undergone this
 operation  for an hour and a quarter1  
during which eighty quarts of gas were  
thrown in1 he came out of the box and   
began to respire twenty quarts  of      
unmingled nitrous oxide4 8,a thrilling10

 says he1 8extending from  the chest to 
the extremities1 was almost immediately 
produced4 ,i felt  a sense of tangible  
extension highly pleasurable in every   
kind2 my  visible impressions were      
dazzling and apparently magnified2 ,i   
heard  distinctly every sound in the    
room1 and ,i was perfectly aware of my  
situation4 ,by degrees1 as the          
pleasurable sensation increased1 ,i lost
  all connexion with external things2   
trains of vivid visible images  rapidly 
passed through my mind1 and were        
connected with words in such  a manner  
as to produce perceptions perfectly     
novel4 ,i existed in a  world of newly  
connected and newly modified ideas4     
,when ,i was awakened  from this same   
delirious trance by ,dr4 ,kinglake1 who 
took the bag from  my mouth1 indignation
 and pride were the first feelings      
produced by  the sight of the persons   
about me4 ,my emotions were enthusiastic
 and  sublime1 and for a moment ,i      
walked round the room1 perfectly        

regardless  of what was said to me4 ,as 
,i recovered my former state of mind1 ,i
 felt  an inclination to communicate the
 discoveries ,i had made during the     
experiment4 ,i endeavoured to recall the
 ideas2 they were feeble and            
indistinct4 ,one recollection of terms1 
however1 presented itself1 and  with the
 most intense belief and prophetic      
manner ,i exclaimed to ,dr4  ,kinglake1 
#8,nothing exists but thoughts2 the     
universe is composed of  impressions1   
ideas1 pleasures1 and pains6'0    ,these
 remarkable properties induced several  
persons to repeat the  experiment of    
breathing this exhilarating medicine4   
,its effects were1  as might have been  
expected1 various in different          
individuals2 but its  general effect was
 to produce in the gravest and most     
phlegmatic the  highest degree of       
exhilaration and happiness unaccompanied
 with languor  or depression4 ,in some  
it created an irresistible disposition  
to laugh1  and in others a propensity to

 muscular exertion4 ,in some it impaired
  the intellectual functions1 and in    
several it had no sensible effect1  even
 when it was breathed in the purest     
state1 and in considerable  quantities4 
,it would be an inquiry of no slight    
interest to ascertain  the influence of 
this gas over persons of various bodily 
temperaments1  and upon minds varying in
 their intellectual and moral character4
    ,although ,sir ,humphrey ,davy      
experienced no unpleasant effects from  
the  inhalation of the nitrous oxide1   
yet such effects are undoubtedly        
produced2 and there is reason to believe
 that even permanent changes  in the    
constitution may be induced by the      
operation of this remarkable  stimulant4
 ,two very interesting cases of this    
kind presented themselves  to ,professor
 ,silliman1 of ,yale ,college1 when the 
nitrous oxide was  administered to some 
of his pupils4 ,the students had been in
 the habit1  for several years1 of      
preparing this gas1 and administering it

 to  one another1 and these two cases   
were the only remarkable ones which     
deserved to be recorded4 ,we shall      
describe them in ,professor ,silliman's 
own words3--    8,a gentleman1 about    
nineteen years of age1 of a sanguine    
temperament1  and cheerful temper1 and  
in the most perfect health1 inhaled the 
usual  quantity of the nitrous oxide1   
when prepared in the ordinary manner4   
,immediately his feelings were          
uncommonly elevated1 so that1 as he     
expressed it1 he could not refrain from 
dancing and shouting4 ,indeed  to such a
 degree was he excited1 that he was     
thrown into a frightful  fit of         
delirium1 and his exertions became so   
violent1 that after a  while he sank to 
the earth exhausted1 and there remained1
 until having  by quiet in some degree  
recovered his strength1 he again arose1 
only  to renew the most convulsive      
muscular efforts1 and the most piercing 
screams and cries2 within a few moments1
 overpowered by the intensity  of the   

paroxysm1 he again fell to the ground1  
apparently senseless1 and  panting      
vehemently4 ,the long continuance and   
violence of the affection  alarmed his  
companions1 and they ran for            
professional assistance4 ,they  were1   
however1 encouraged by the person to    
whom they applied to hope  that he would
 come out of his trance without injury2 
but for the space  of two hours these   
symptoms continued2 he was perfectly    
unconscious of  what he was doing1 and  
was in every respect like a maniac4 ,he 
states1  however1 that his feelings     
vibrated between perfect happiness and  
the  most consummate misery4 ,in the    
course of the afternoon1 and after the  
first violent effects had subsided1 he  
was compelled to lie down two or  three 
times from excessive fatigue1 although  
he was immediately aroused  upon any    
one's entering the room4 ,the effects   
remained in a degree for  three or four 
days1 accompanied by a hoarseness1 which
 he attributed  to the exertion made    

while under the immediate influence of  
the gas4  ,this case should produce a   
degree of caution1 especially in persons
 of  a sanguine temperament1 whom1 much 
more frequently than others1 we have    
seen painfully1 and even alarmingly     
affected40    ,the other case described 
by ,professor ,silliman was that of a   
man of  mature age1 and of a grave and  
respectable character4 8,for nearly  two
 years previous to his taking the gas1  
his health had been very  delicate1 and 
his mind frequently gloomy and          
depressed4 ,this was  peculiarly the    
case for a few days immediately         
preceding that time2  and his general   
state of health was such1 that he was   
obliged almost  entirely to discontinue 
his studies1 and was about to have      
recourse  to medical assistance4 ,in    
this state of bodily and mental         
debility1  he inspired about three      
quarts of nitrous oxide4 ,the           
consequences  were1 an astonishing      
invigoration of his whole system1 and   

the most  exquisite perceptions of      
delight4 ,these were manifested by an   
uncommon  disposition for pleasantry and
 mirth1 and by extraordinary muscular   
power4 ,the effects of the gas were felt
 without diminution for at least  thirty
 hours1 and in a greater or less degree 
for more than a week4    8,but the most 
remarkable effect was that upon the     
organs of taste4  ,antecedently to      
taking the gas1 he exhibited no peculiar
 choice in  the articles of food1 but   
immediately subsequent to that event1 he
  manifested a taste for such things    
only as were sweet1 and for  several    
days ate nothing but sweet cake4 ,indeed
 this singular taste  was carried to    
such excess1 that he used sugar and     
molasses1 not  only upon his bread and  
butter1 and lighter food1 but upon his  
meat  and vegetables4 ,this he continues
 to do even at the present time2  and   
although eight weeks have elapsed since 
he inspired the gas1 he  is still found 
pouring molasses over beef1 fish1       

poultry1 potatoes1  cabbage1 or whatever
 animal or vegetable food is placed     
before him4    8,his health and spirits 
since that time have been uniformly     
good1 and  he attributes the restoration
 of his strength and mental energy to   
the  influence of the nitrous oxide4 ,he
 is entirely regular in his mind1 and   
now experiences no uncommon             
exhilaration1 but is habitually         
cheerful1  while before he was as       
habitually grave1 and even to a degree  
gloomy40           99       99       99 
99       99    ,such is a brief and     
general account of the principal        
phenomena of  ,nature1 and the most     
remarkable deductions of science1 to    
which  the name of ,natural ,magic has  
been applied4 ,if those who have not    
hitherto sought for instruction and     
amusement in the study of the  material 
world1 shall have found a portion of    
either in the preceding  pages1 they    
will not fail to extend their inquiries 
to other popular  departments of        

science1 even if they are less marked   
with the  attributes of the marvellous4 
,in every region of space1 from the     
infinitely distant recesses of the      
heavens to the 8dark unfathomed  caves  
of ocean10 the ,almighty has erected    
monuments of miraculous  grandeur1 which
 proclaim the power1 the wisdom1 and the
 beneficence  of their ,author4 ,the    
inscriptions which they bear--the       
hand-writing  which shines upon their   
walls--appeal to the understanding and  
to  the affections1 and demand the      
admiration and the gratitude of every   
rational being4 ,to remain willingly    
ignorant of these revelations of  the   
,divine ,power is a crime next to that  
of rejecting the revelation  of the     
,divine ,will4 ,knowledge1 indeed1 is at
 once the handmaid and the  companion of
 true religion4 ,they mutually adorn and
 support each other2  and beyond the    
immediate circle of our secular duties1 
they are the  only objects of rational  
ambition4 ,while the calm deductions of 

reason  regulate the ardour of          
,christian zeal1 the warmth of a holy   
enthusiasm  gives a fixed brightness to 
the glimmering lights of knowledge4     
,it is one of the darkest spots in the  
history of man1 that these noble  gifts 
have been so seldom combined4 ,in the   
young mind alone can the two  kindred   
seeds be effectually sown2 and among the
 improvements which  some of our public 
institutions require1 we yet hope to    
witness a  national system of           
instruction1 in which the volumes of    
,nature and of  ,revelation shall be    
simultaneously perused4      ,d4        
,,brewster4      ,,allerly1 ,april      
#bdth1 #ahcb4                           
,,the ,,end4    ,j4 ,,haddon1 ,,printer1
 ,,castle ,,street1 ,,finsbury4         
,a ,,general ,,descriptive    ,catalogue
    ,,of ,,the    ,,family ,,library2   
,a ,,series ,,of    ,,original ,,and    
,,select ,,works4    ,the ,works sold   
separate1 at #cs4 #f;d4 per ,volume4    
8,,books ,,that ,,you ,,may ,,carry ,,to

 ,,the ,,fire1 ,,and ,,hold ,,readily   
,,in ,,your ,,hand1   ,,are ,,the ,,most
 ,,useful ,,after ,,all4 ,a ,,man ,,will
 ,,often ,,look ,,at ,,them1 ,,and ,,be 
,,tempted ,,to ,,go ,,on1 ,,when ,,he   
,,would ,,have ,,been ,,frightened ,,at 
,,books ,,of ,a   ,,larger ,,size1 ,,and
 ,,of ,a ,,more ,,erudite               
,,appearance40--,,dr4 ,,johnson4        
8,,mr4 ,,murray',s ,library4444 ,a very 
excellent and always entertaining       
,miscellany40--,edinburgh ,review4      
8,,mr4 ,,murray',s ,family ,library4444 
,a title1 which1 from the valuable  and 
entertaining matter the collection      
contains1 as well as from the  careful  
style of its execution1 it well         
deserves4 ,no family1 indeed1  in which 
there are children to be brought up1    
ought to be without this  ,library1 as  
it furnishes the readiest resources for 
that education1  which ought to         
accompany or succeed that of the        
boarding-school or  the academy1 and is 
infinitely more conducive than either to

 the  cultivation of the                
intellect40--,monthly ,review4          
,,london3    ,,william ,,tegg ,,and     
,co41    #he1 ,,queen ,,street1         
,,cheapside4      ,,address4      ,it is
 a source of no inconsiderable          
gratification to find the  anticipations
 with which the ,,family ,,library was  
commenced exceeded by  its success1 and 
the liberal patronage bestowed on it4   
,the best proof of this is the fact that
 of many of the volumes more  than      
#dj1jjj copies have been sold in this   
country alone4 ,it has been  warmly     
commended in the journals of ,great     
,britain1 in those of ,france1          
,germany1 ,italy1 and other parts of    
,europe4    ,its general estimation is  
also proved by its having been reprinted
 in  ,america1 and translated into most 
of the ,continental ,languages4    ,upon
 the copyright alone of the ,works of   
the ,series1 upwards of  #ab1jjj has    
been expended1 and the list of          
,contributors embraces the              

distinguished names of      ,,sir       
,,walter ,,scott1 ,,bart4    ,,mr4      
,,southey4    ,,mr4 ,,lockhart4         
,,rev4 ,h4 ,h4 ,,milman4    ,,washington
 ,,irving4    ,,allan ,,cunningham4     
,,mr4 ,,tytler4    ,,rev4 ,j4           
,,williams4    ,,mr4 ,,barrow 7of the   
,admiralty74    ,,rev4 ,j4 ,j4 ,,blunt4 
,,rev4 ,e4 ,,smedley4    ,,rev4 ,g4 ,r4 
,,gleig4    ,,sir ,,david ,,brewster4   
,,mr4 ,,coleridge4    ,,major ,,sir ,f4 
,b4 ,,head4    ,,mr4 ,,davenport4       
,,mr4 ,,crofton ,,croker4    ,,mr4      
,,lander4    ,,cyrus ,,edmonds4    ,,mr4
 ,,bucke4    ,w4 ,e4 ,,aytoun4    ,,rev4
 ,t4 ,,chetwode ,,eustace4    ,,mr4     
,,roscoe4    ,,sir ,,francis ,,palgrave4
    ,with the assistance of persons of  
such eminent talent was commenced the   
design of supplying the deficiencies of 
,english ,literature1 by a series  of   
,standard ,works1 which1 with excellence
 of execution1 should combine  the      
advantages of lowness of price1         
convenience of size and form1 and       

elegance of illustration4    ,while the 
moderate cost has placed the ,work      
within the reach of all  classes of     
,readers1 the interesting nature of the 
subjects1 and the  popular mode of      
treating them1 render it well suited for
 the perusal  of ,young ,persons1 and   
calculated to stimulate in them a taste 
for  ,literature and ,science4 ,in the  
beauty of its ,embellishments1 the      
,,family  ,,library has surpassed all   
its ,contemporaries2 and no pains or    
cost have  been spared to render each   
,volume as attractive externally1 as it 
will  prove entertaining and useful on  
perusal4 ,with these recommendations1   
this ,publication will be found to      
deserve a conspicuous place in every    
well-selected ,library2 and as it may be
 purchased in its complete  state1 or   
separate1 each work being complete in   
itself1 it will  furnish valuable       
,literary ,presents1 adapted to the     
means and tastes of  all classes of     
,purchasers4    ,the ,volumes of which  

the ,,family ,,library consists1 may be 
classed under  the following heads3--   
,biography4      ,,life ,,of ,,napoleon4
    ,,the ,,court ,,and ,,camp ,,of     
,,buonaparte4    ,,lives ,,of ,,british 
,,painters1 ,,sculptors1 ,,and          
,,architects4    ,,life ,,of ,,columbus4
    ,,lives ,,and ,,adventures ,,of     
,,the ,,companions ,,of ,,columbus4     
,,life ,,of ,,nelson4    ,,lives ,,of   
,,british ,,physicians4    ,,life ,,of  
,,bruce4    ,,lives ,,of ,,scottish     
,,worthies4    ,,life ,,of ,,sir ,,isaac
 ,,newton4    ,,life ,,of ,,peter ,,the 
,,great4    ,,life ,,and ,,times ,,of   
,,washington4    ,,life ,,of ,,ali      
,,pasha4    ,,life ,,of ,,duke ,,of     
,,marlborough4    ,,life ,,of           
,,cervantes4    ,,life ,,of ,,cicero4   
,,life ,,of ,,richard ,c,,ur ,,de       
,,lion4    ,,life ,,of ,,mahomet4       
,,lives ,,of ,,enterprising ,,men4      
,history4      ,,history ,,of ,,the     
,,jews4    ,,history ,,of ,,india4      
,,history ,,of ,,venice4    ,,history   

,,of ,,the ,,anglo-,,saxons4            
,,reformation ,,in ,,england4           
,,tytler',s ,,general ,,history4    ,,de
 ,,foe',s ,,history ,,of ,,the ,,plague 
,,year4    ,,narrative ,,of             
,,napoleon',s ,,expedition ,,to         
,,russia4    ,,the ,,ruins ,,of         
,,ancient ,,cities4    ,,the ,,mutiny   
,,at ,,the ,,nore4    ,voyages and      
,travels4      ,,lander',s ,,discoveries
 ,,in ,,africa4    ,,family ,,tour ,,in 
,,holland4    ,,narrative ,,of ,,the    
,,mutiny ,,of ,,the ,,bounty4    ,,six  
,,months ,,in ,,the ,,west ,,indies4    
,,eustace',s ,,classical ,,tour ,,in    
,,italy4    ,state ,trials4             
,,trials ,,of ,,charles ,,the ,,first   
,,and ,,the ,,regicides4    ,natural    
,history and ,science4      ,a ,,popular
 ,,natural ,,history ,,of ,,insects4    
,,letters ,,on ,,natural ,,magic4       
,,demonology ,,and ,,witchcraft4        
,,wesley',s ,,natural ,,philosophy4     
,miscellaneous4      ,,salmagundi4 ,,by 
,,washington ,,irving4    ,,sketch      

,,book4 ,,by ,,ditto4    ,,croker',s    
,,fairy ,,legends4    ,,knickerbocker',s
 ,,new ,,york4    ,,sketches ,,of       
,,imposture ,,and ,,credulity4          
,,chronicles ,,of ,,london ,,bridge4    
,,narratives ,,of ,,peril ,,and         
,,suffering4      ,,the    ,,family     
,,library4      ,a ,,new ,,history ,,of 
,,the ,,anglo-,,saxons4    ,by ,,sir    
,,francis ,,palgrave4 ,with             
,illustrative ,woodcuts4    ,this work  
7as the preface mentions7 was intended  
in imitation of the  ,tales of my       
,grandfather4 8,let me hope10 the author
 says1 8that  occasionally1 whilst the  
younger branches find amusement in the  
tales  and adventures here brought      
together1 some of the older folks may   
not be unwilling to take this little    
summary in hand1 as a temporary         
substitute for the unmanageable folios  
produced by the unwearied  industry of  
,saville1 ,twysden1 and ,warton1 and    
,wilkins40      ,,the ,,reformation ,,in
 ,,england4    ,by the ,,rev4 ,j4 ,j4   

,,blunt4    ,this is a compact but      
lively and entertaining sketch of the   
,reformation1 and the personal history  
of the founders of our ,national        
,church4    ,the ,reformation is one of 
the most remarkable events in our       
history1  whether in relation to        
politics or religion2 for its influence 
was  most powerful upon both4 ,the      
reading1 profession1 and taste of the   
author have led him to regard it chiefly
 in the latter light2 and1  therefore1  
brief as the sketch is1 it will not be  
found of the nature  of an abridgment1  
but a continuous though succinct account
 of the rise1  progress1 and            
consummation of that great revolution of
 the ,church of  ,england4     ,this    
book is included in the list of works of
 the ,society for  ,promoting ,christian
 ,knowledge4      ,,the ,,trials ,,of   
,,charles ,,the ,,first1    ,,and ,,of  
,,some ,,of ,,the ,,regicides4    ,with 
,biographies of ,,bradshaw1 ,,ireton1   
,,harrison1 c41 and  ,illustrative      

,notes1 ,legal and ,historical4         
,portrait1 ,views1 c4    ,a clear and   
detailed account of the most remarkable 
and important of  ,english ,causes      
,clbres1 with a narrative of the        
distinguishing  events of that          
interesting period of our history4      
,,history ,,of ,,the ,,expedition ,,to  
,,russia ,,undertaken ,,by ,,the        
,,emperor ,,napoleon4    ,by ,,general  
,,count ,,philip ,,de ,,segur4 #b ,vols4
    ,the established interest created by
 ,count ,segur's history renders any    
commendation vain--any anticipation of  
its contents of no value4 ,when  those  
recollections of the most disastrous    
campaign ever undertaken  were first    
published1 they were charged with       
exaggeration1 if not  falsehood2 but a  
severe scrutiny has shown that1 with the
 exception  of a few unimportant errors1
 every statement in this extraordinary  
production is entitled to public        
confidence4 ,the translation made  for  
the ,family ,library exhibits evidence  

of the utmost care1 and the             
misstatements into which the author     
inadvertently fell are corrected by  the
 translator4      ,,the    ,,life ,,of  
,,john1 ,,duke ,,of ,,marlboro'4    ,by 
,,charles ,,bucke4    ,editorial        
ingenuity1 and economy in printing1 have
 reduced the  varied annals of the great
 ,marlborough within the grasp of       
moderate  literary industry4 ,the editor
 has drawn a fair and truthful picture  
of the martial ,duke1 lauding his       
political and public virtues without    
concealing those blemishes that his     
warmest advocates confess to  be        
equivocal4 ,when the balance betwixt    
good and evil is struck1  ,marlborough  
stands out in bold relief in the picture
 of history2 and  had his brilliant     
victories been followed by firm and     
honest treaties1  their effects1 like   
those of ,waterloo1 would have been felt
 in the  happiness of the ,british      
dominions4      ,,the ,,life ,,and      
,,writings ,,of ,,miguel ,,de           

,,cervantes ,,saavedra4    ,with        
,literary and ,historical ,illustrations
 by ,,thos4 ,,roscoe1 ,esq4    ,it is   
not strange that the writings of        
,cervantes1 with the exception  of ,don 
,quixote1 should have so long remained  
unknown1 since it was  generally        
asserted that 8the ,spaniards had but   
one good book1 that  one which had made 
all the others ridiculous40 ,the        
chef-d'uvre is  translated into every   
language of ,europe1 while the same     
author's  plays and novels are sealed   
against all but ,spanish scholars2 and  
his  chivalrous life1 previous to this  
publication1 buried in oblivion to      
which the anarchy of ,spain had         
consigned it4 ,cervantes flourished in  
the reign of ,philip ,,ii41 and was     
contemporary with ,lope de ,vega4       
,,the ,,life ,,of ,,nelson4    ,by      
,,robert ,,southey1 ,esq41 ,,ll4,d41    
,poet ,laureate1 c4    ,with numerous   
,woodcuts from ,designs by ,,george     
,,cruikshank1 engraved  by ,,thompson   

and ,,williams4    ,in order to promote 
the wishes and intention of the author1 
and to give  the work the widest        
circulation1 it has been printed in its 
present  form1 at one-third of the      
original price1 with embellishments by  
the  most talented artists4     8,many  
,lives of ,nelson have been written1 but
 one was yet wanting1   clear and       
concise enough to become a manual for   
the young sailor1   which he may carry  
about with him till he has treasured up 
the example   in his memory and in his  
heart40--,author's ,preface4     8,a    
work which1 as long as the ,english     
language is understood1 will be         
regarded as one of the finest monuments 
that genius ever raised to              
valour40--,monthly ,review4      ,,the  
,,life ,,of ,,mahomet1    ,,founder ,,of
 ,,the ,,religion ,,of ,,islam1 ,,and   
,,of ,,the ,,empire ,,of ,,the          
,,saracens4    ,by ,,rev4 ,,samuel      
,,green4    ,with the exception of the  
religion of the ,gospel1 that of        

,mahomet has  produced the greatest     
revolution recorded in history1 and     
effected the  greatest changes in the   
state of the civilized world2 its       
history  and character1 therefore1      
become an object of curiosity with every
  enlightened mind4 ,considered as part 
of the general annals of the  world1    
unconnected with religion1 it furnishes 
most interesting records  of the human  
race2 but viewed as part of the chain of
 predicted events1  having a direct     
reference to the ,christian ,church1 it 
urges a stronger  claim to our          
attention4 ,the events of ,mahomet's    
life are to be found  in works          
inaccessible from their costliness1     
discouraging from their  bulk1 and      
sometimes written in ,eastern           
characters4 ,this volume is a           
compilation from the most authentic4    
,,journal    ,,of ,,an ,,expedition ,,to
 ,,explore ,,the ,,course ,,and         
,,termination ,,of ,,the ,,niger4    ,by
 ,,richard and ,,john ,,lander4    ,with

 ,portraits1 ,engravings1 and a ,map1   
showing the course of the  ,niger4      
,with slight encouragement from the     
,colonial ,office1 these young men set  
out on an enterprise which in all       
previous instances had led to death2    
and all who knew the nature of the      
climate1 and the hardships they  must   
encounter1 predicted that the only news 
their countrymen would  ever receive    
concerning them1 would be some obscure  
rumour of their  destruction4 ,the      
narrative shows how often such          
predictions were on  the point of being 
verified4 ,there is scarcely a misery to
 be endured  by human nature that these 
young men have not encountered2 they    
have  been frequently on the brink of   
death--they have been imprisoned--they  
have been sold as slaves--they have been
 plundered1 and obliged to swim  for    
their lives1 not sure1 in the end1 that 
they were not swimming  into greater    
danger--and1 to crown the whole1 they   
have been brutally  treated and nearly  

sacrificed to the cupidity and revenge  
of savages  by one of their own         
countrymen4 ,in spite of all these      
obstacles1 by  means of patience and    
perseverance1 by enthusiasm and         
resignation1 by  courage and            
long-suffering1 they finally triumphed  
over every species  of resistance1 and1 
what is more1 completely gained their   
object4    ,the result of ,captain      
,clapperton's discoveries was a very    
shrewd guess  that the ,niger flowed    
westward1 and into the ,bight of ,benin4
 ,with the  view of ascertaining this1  
the ,landers were set down at the same  
point  of the coast of ,guinea where the
 former expedition had commenced4       
,,the ,,life ,,of ,,marcus ,,tullius    
,,cicero4    ,by ,j4 ,f4 ,,hollings4    
,the name of ,cicero himself--the       
universal admiration of his genius--the 
era in which he flourished--and the part
 he enacted1 bring his memoirs  within  
the circle of subjects suited to        
domestic education4 ,his ,life1  by     

,middleton1 is more acceptable to the   
learned than the learner1 and  this     
conclusion has led to this epitome1 in  
which the text contains the             
uninterrupted personal memoir of the    
philosopher in a popular form2  while   
such information as belongs more        
distinctively to the department  of     
ancient literature is conveyed by means 
of notes and references4      ,,six     
,,months ,,in ,,the ,,west ,,indies4    
,by ,,henry ,,nelson ,,coleridge1 ,m4,a4
    ,this little work1 which has already
 received public approbation1 is        
calculated to amuse in no ordinary      
degree1 for the descriptions of  scenery
 are vivid1 the pictures of society     
graphic1 and the adventures  and        
anecdotes interesting and varied4       
,,lives    ,,of ,,the ,,most ,,eminent  
,,british ,,painters1 ,,sculptors1 ,,and
 ,,architects4    ,by ,,allan           
,,cunningham4    #f vols41 with         
,portraits of ,thirty-two of the most   
distinguished  ,british ,artists1 c4    

,the author has collected in six small  
volumes the ,history of ,art in         
,england1 and the ,lives1 ,characters1  
and ,works of its ,professors1--the     
materials for which were previously     
scattered through many volumes4  ,on    
this account1 these biographies have    
been considered a valuable  acquisition 
to literature2 and although the critical
 observations will  render them valuable
 to the student1 yet1 being free from   
the dry  technicalities of virt1 and    
abounding with personal anecdote1 they  
are  not less alluring to the ordinary  
reader4    ,the annals of ,art1 and the 
lives of its followers1 though deficient
  in the spirit-stirring incidents of   
the warrior and the politician1  possess
 an interest not less attractive4 ,the  
labours and struggles  of genius1 the   
success of perseverance1 and the        
inutility of natural  talent separated  
from prudence1 as exemplified in these  
biographies1  will afford a useful moral
 lesson1 at the same time that the      

perusal of  the stories of such lives is
 a source of pleasure and entertainment4
      ,,the ,,history ,,of ,,the ,,jews4
    ,by ,,rev4 ,h4 ,h4 ,,milman4        
,complete in #c vols4    ,with ,original
 ,maps and ,woodcuts4    ,with the      
exception of ,josephus1 we have no      
historian of the ,jews1 and  he lived at
 a period too remote and too limited to 
enable him to do  justice to his        
subject4 ,it is true1 many events have  
been narrated  by ,rollin1 and the      
authors of the ,universal ,history1 and 
noticed  by commentators1--but a        
narrative at once ,christian and liberal
 in  its tone1 spirited and elegant in  
its language1 and depicting with        
something like kindred enthusiasm and   
eloquence1 the manners1 wars1  religion1
 and policy of the most extraordinary of
 nations1 was still  wanting4    ,the   
object of the present work is strictly  
historical1--yet it affords  elucidation
 of many obscure passages in the ,old   
,testament2 avails  itself of the casual

 evidence of heathen writers2 and throws
 new light  on the manners and customs  
of the 8,unchanging ,east10 by          
references to  the ablest modern        
travellers4      ,,the ,,natural        
,,history ,,of ,,insects4    ,with very 
numerous ,woodcuts4 #b vols4    ,the    
study of ,natural ,history is at all    
times pleasing and instructive2  the    
object on this occasion has been to     
render it doubly captivating  by a plain
 and simple style1 and by the numerous  
wood engravings4 ,the  extravagant price
 of books of ,natural ,history has      
deterred many1 and it  is no            
exaggeration to assert that the         
information and embellishments          
contained in these volumes could hardly 
be purchased in any other form  at a    
cost of less than several pounds4       
,,compendium ,,of ,,natural             
,,philosophy3    ,a ,,survey ,,of ,,the 
,,wisdom ,,of ,,god ,,in ,,the          
,,creation4    ,by ,,john ,,wesley4 ,a  
,new ,edition1 by ,,robert ,,mudie4 #c  

,vols4    ,john ,wesley's name is a     
guarantee for the moral rectitude of the
  original volumes1 as well as the full 
information which they contained  at    
first publication2 but since that time  
the progress of natural  science has    
been greater than during the whole      
previous period  of human history4      
,following ,wesley's arrangement1 the   
editor has  incorporated the most recent
 discoveries1 adding many new facts to  
those of ,baron ,cuvier3 he has pursued 
the history of invertebrated  animals   
down to the very verge of animal        
existence1 and annexed a  full account  
of the vegetable kingdom4 ,the re-edited
 work1 therefore1  is not only          
introductory on detached portions of    
nature to students1  but recapitulatory 
to such as have already consulted the   
details4 ,it  may not be immaterial to  
remark that1 while controverted points  
are  studiously avoided1 the very latest
 discoveries are introduced1 and  the   
language employed is free from that     

technicality which may gratify  pedantry
 with out promoting knowledge4          
,,the ,,life ,,of ,,ali ,,pasha ,,of    
,,tepeleni    ,,vizier ,,of ,,epirus4   
,by ,r4 ,a4 ,,davenport4    ,it is a    
common error to imagine that a greater  
number of individuals  rise in ,england 
than in other countries2 more1          
certainly1 attain wealth  and           
respectability under free than despotic 
governments2 but it is  under the latter
 only that the very humblest and most   
illiterate1 if  possessed of courage and
 cunning1 may approach to the steps of  
the  throne itself4 ,of the numerous    
examples which ,turkish history affords1
  none ran a more celebrated career than
 ,ali ,pasha4 ,rendering himself        
independent by a series of rebellions1  
his throne was supported by the  blood  
of thousands2 yet1 notwithstanding the  
means by which he acquired  power1      
,napoleon treated with him1--,lord      
,byron was his guest1--and  ,england    
accepted his friendship4 ,turkish       

history1 being a record of the          
indulgence of the worst passions of     
human nature1 is always a terrible      
romance1 but the life of ,ali ,pasha    
exceeds in guilt and horror the  most   
infamous periods of ,ottoman history4   
,the great tragedy in which he          
performed so principal a part1 was      
concluded by his own assassination  in  
the throne-room of his palace1 in a     
manner almost too merciful for  such a  
ferocious monster4      ,,the ,,history 
,,of ,,british ,,india4    ,by the      
,,rev4 ,g4 ,r4 ,,gleig1 ,f4,r4,s4 #d    
,vols4    ,with a ,map and #aj          
,engravings4    ,a ,history of ,india in
 a portable form1 and familiar style1   
having been  considered a desideratum1  
the present work was undertaken4 ,it    
commences  with the early annals and    
first civilization of the ,hindoos1     
traces the  progress and decline of the 
,mahometan power1 and brings the history
 of  the success of the ,british arms   
down to the permanent establishment of  

the ,india ,company1 and the foundation 
of that stupendous ,empire4 ,it is      
among the annals of the ,east that the  
real ,romance of ,history must  be      
sought4 ,in the variety of marvellous   
incidents1 the unexpected turn  of      
events1 the sudden alternation of       
fortune1 we might fancy we were  reading
 an ,oriental fable--a tale from the    
,arabian ,nights1 rather than  sober    
history4      ,,sketches ,,from ,,the   
,,history ,,of ,,venice4    ,with eight 
,views after ,prout1 twenty-nine ,cuts  
after ,,titian1 ,maps1  etc4    ,few can
 explore for themselves the treasures of
 the ,italian ,chronicles4  ,the author 
of this work has laid open their stores 
for the benefit of  ,english            
readers1--gleaning from them            
characteristic incidents1 amusing       
stories and anecdotes2 while he has     
sustained all the dignity of  historical
 research4    ,the writer has avoided   
the mistakes into which mere compilers  
fall2--he  has not sunk into a mere     

annalist1 transcribing a dry register of
  facts1 but he either passes over      
entirely1 or touches very slightly1     
events of minor importance1 and reserves
 himself for those more  momentous and  
interesting transactions which require  
to be more fully  displayed4 ,the beauty
 of style in which these volumes are    
written  has attracted general notice1  
and the applause of the most competent  
judges1--in this respect1 indeed1 they  
yield to no work of the series4         
,,letters ,,on ,,demonology ,,and       
,,witchcraft4    ,by ,,sir ,,walter     
,,scott1 ,,bart4    ,no subject could   
have been better adapted to the lamented
 author of  8,waverley0 than 8the       
history of that dark chapter of human   
nature0 to  which this volume is        
devoted4 ,sir ,walter has given         
sufficient evidence  in his novels and  
romances of his acquaintance with the   
superstitions  of our own and remoter   
times4 ,in this volume he has laid open 
the  stores of his memory and reading1  

has condensed and elucidated the        
subject2 in many cases explaining by    
natural causes occurrences  supposed to 
be supernatural4      ,,letters ,,on    
,,natural ,,magic4    ,,addressed ,,to  
,,sir ,,walter ,,scott4    ,by ,,sir    
,,david ,,brewster1 ,k4,g4,h4    ,a ,new
 ,edition1 ,illustrated with upwards of 
#hj ,woodcuts4    ,the author of this   
volume passes under review 8the         
principal phenomena  of nature and the  
leading constructions of art which bear 
the impress  of a supernatural          
character10 and more especially 8those  
singular  illusions of sense by which   
the most perfect organs either fail to  
perform their functions or perform them 
faithlessly1 and where the  efforts and 
the creations of the mind predominate   
over the direct  perceptions of external
 nature40    ,these are themes full of  
interest and worthy of the labour       
bestowed  upon them by the philosophic  
author4 ,it is lamentable to think how  
many minds rest contented with the most 

unphilosophical apology for  ignorance1 
by designating the acts they do not     
examine1 wonders or  mysteries1--while  
to the mass of men1 such acts are       
inexplicable1  except on some theory of 
superhuman agency1 as absurd as it is   
erroneous4 ,the ,letters of ,sir ,david 
,brewster will disabuse both  classes4  
,to the first1 he furnishes             
philosophical data for explaining  many 
hitherto puzzling appearances--to the   
last1 he supplies the means  of escape  
from absurdities calculated to retain   
them in mental slavery4    ,the eye and 
the ear are of course the great organs  
of deception1  and accordingly optical  
illusions occupy a considerable portion 
of  the volume4 ,the illusions depending
 on the ear succeed1 and after  these1  
we are treated with amusing descriptions
 of feats of strength1  of mechanical   
automata1 and of some of the more       
popular wonders of  chemistry4 ,under   
each of these divisions1 anecdotes of   
the most  interesting kind illustrate   

the author's explanations1 and no       
subject1  in itself grave and important1
 was ever on the whole treated in a more
  amusing manner4      ,,life ,,and     
,,times ,,of ,,washington4    ,by       
,,cyrus ,r4 ,,edmonds4 #b ,vols4    ,as 
the foundation of the ,american         
,republic is attributable to ,british   
error1 its history is identified with   
our own4 ,those who have related  the   
events of that memorable period1 and    
drawn the character of  the             
patriot-general1 living too near the    
epoch1 were dazzled1 and  discovered    
only the beauty of republican           
principles4 ,written when  party-feeling
 had died away1 and limited monarchy    
allowed to vindicate  its superiority1  
,mr4 ,edmonds's ,life of ,washington is 
free from that  nationality which       
disfigures biography1 and fearlessly    
defends ,british  institutions against  
the advocates of democracy4 ,the more   
voluminous  memoirs of the virtuous     
republican chief abound with ,american  

prejudices2 these volumes are ,english  
both in style and sentiment4      ,,the 
,,life ,,of ,,napoleon ,,buonaparte4    
,with #ae ,engravings on ,steel and     
,wood1 by ,,finden and ,,thompson2 the  
,woodcuts from ,designs by ,,geo4       
,,cruikshank4    ,the fact that since   
the publication of this work1           
,,seven-,,and-,,twenty  ,,thousand      
copies have been disposed of in this    
country1 beside various  editions in    
,america1--will speak more in its favour
 than the most  artful and high-flown   
praise4 ,it is an epitome of all that   
has been  proved to be true concerning  
the career of the most extraordinary    
man of the last thousand years4 ,we     
possessed no previous epitome of  his   
history2 and notwithstanding the        
smallness of space into which it  is    
compressed1 the narrative is clear4 ,the
 ,life of ,napoleon1 doubly  interesting
 when relieved of the tediousness of    
useless detail1 has  never been better  
told4 ,volumes so rich in information   

will be devoured  by youth1 and are     
worthy to be consulted by the maturest  
reader4    ,the work is written with    
fairness and impartiality1 free from    
party-spirit1 and the author has        
interwoven with his narrative all the   
new illustrations and anecdotes         
furnished by ,bourrienne and the other  
fast-following memoirs of the ,french   
press4      ,,the ,,ruins ,,of ,,ancient
 ,,cities4    ,by ,,charles ,,bucke4 #b 
,vols4 ,illustrated4    ,cities1 like   
men1 flourish and decay1 and each       
possess their annals4  ,the poetic      
conception of personifying these broken 
records of natural  grandeur originated 
with the editor himself2 but1 in        
carrying out his  design1 he            
acknowledges ,rollin as his guide4 ,this
 elegant and accurate  writer confesses 
that he does not hesitate to rifle the  
cabinets of  others to enrich his own2  
that he often transcribed without       
quoting1  and introduced solid          
reflections borrowed from the sterling  

works of  others4 ,this compilation is  
also a beautiful bead-roll1 the precious
  production of many minds3 it is a fair
 fabric of costly materials  raised by a
 literary architect1 whose industry1    
experience1 and  candour1 are already   
acknowledged by the public4             
,,salmagundi2    ,,or1 ,,the            
,,whim-,,whams ,,and ,,opinions ,,of    
,,launcelot ,,langstaff1 ,,esq4    ,with
 numerous ,cuts by ,,george             
,,cruikshank4    ,the earliest paintings
 of the greatest masters sometimes      
differ  considerably from those of their
 maturer years1 and not unfrequently    
surpass them in brilliancy and          
freshness4 ,if the ,salmagundi ,papers  
be  compared with the subsequent works  
of the same author1 they will not be    
found inferior in originality1 vivacity1
 or virtuous tendency4 ,while  satire is
 the adopted weapon of chastisement1 it 
wounds the vicious  only4 8,we have10   
say the authors1 8no fear of the        
censures of the  wise1 good1 or fair1   

for they will ever be sacred from our   
attacks4  ,we reverence the wise1 love  
the good1 and adore the fair3 we declare
  ourselves champions in their cause--in
 the cause of morality--and we  throw   
our gauntlet to all the world besides40 
,,the ,,life ,,of ,,peter ,,the ,,great4
    ,by ,,john ,,barrow1 ,esq41         
,f4,r4,s41 ,author of the 8,eventful    
,history of the  ,mutiny of the         
,bounty40 ,with ,portrait4    ,the      
author of this ,biographical ,memoir has
 arranged the scattered  fragments of   
,histories1 ,lives1 ,anecdotes1 and     
,notices1 manuscript or  print1 of one  
of the most extraordinary characters    
that ever appeared  in the world1 in any
 age or country2--being full of         
contradictions1 yet  consistent2 a      
promoter of literature1 arts1 and       
sciences1 yet without  education2 8he   
gave a polish10 says ,voltaire1 8to his 
nation1 and was  himself a savage20 he  
taught his people the art of war1 of    
which he was  himself ignorant2 from the

 first glance of a cock-boat1 five      
hundred  miles from the sea1 he became  
an expert ship-builder1 created a fleet1
  partly constructed with his own hands1
 made himself an expert sailor1 a       
skilful pilot1 a great captain3 in      
short1 he changed the manners1 the      
habits1 the laws of the people1 and the 
very face of the country4               
,,sketches ,,of ,,imposture1            
,,deception1 ,,and ,,credulity4         
,credulity is so comprehensive a term1  
that greater difficulties are           
encountered in selecting than           
multiplying examples4 ,these 8,sketches0
  take an extensive range over the      
,pagan superstitions--tell of pretended 
,messiahs1 false prophets1 and mock     
miracles--describe ,hindoo and other    
,oriental deceptions in religious       
worship--relate of royal impostors1     
military stratagems1 literary cheats1   
and commercial bubbles--unfold  the     
mysteries of thefts and forgeries1 and  
conclude with an interesting  account of

 the delusions of alchemy and medical   
frauds4 ,the work may  be considered as 
a supplement to ,scott's 8,letters on   
,demonology10 and  ,brewster's on       
8,natural ,magic40      ,,the           
,,chronicles ,,of ,,london ,,bridge4    
,by ,,an ,,antiquary4 ,illustrated4     
,this is an original work1 and the      
reader will at once perceive that  the  
8,nominis umbra0 of 8,an ,antiquary0    
conceals a mind of no ordinary          
mould--the possessor of no common store 
of erudition4 ,a velvet cushion  has    
been the nucleus of the ,history of the 
,reformed ,church--a library  chair that
 of a history of literature4 ,in this   
volume ,london ,bridge is  selected as  
the bond that is to bind1 the avenue    
that is to lead from1  ancient to modern
 ,london4 ,much valuable civic history  
and legend is  here adorned with        
language1 precise1 classical1 and       
nervous2 while the  illustrations1      
fifty-six in number1 present more       
perfect reminiscences  of society and   

manners in the olden time than the most 
technical and  laboured descriptions4   
,,the ,,life ,,of ,,alexander ,,the     
,,great4    ,by the ,,rev4 ,,john       
,,williams1 ,m4,a41    ,head ,master of 
the ,edinburgh ,academy4 ,map and       
,woodcuts4    ,this volume fills a blank
 in the ,historical ,library1 and       
furnishes a  capital school-manual4 ,it 
is not confined to the mere exploits of 
the  ,macedonian hero1 but contains a   
masterly view of the times in which  he 
lived1 and of the manners1 customs1 etc4
 of the ,greeks1 ,persians1  ,egyptians1
 ,arabs1 and ,indians1 and other        
nations4 ,the whole story is  told in a 
manner calculated to stimulate the      
curiosity and rouse the  reflection of  
the youthful reader4      ,,the         
,,sketch ,,book ,,of ,,geoffry ,,crayon1
 ,,esq4    #b ,vols4    ,had ,mr4       
,irving left no other memorial of his   
genius than the ,sketch  ,book1 it would
 be alone sufficient to a pedestal in   
the ,palatine  ,library of the ,x,i,xth4

 century4 ,justly may he contend with   
the  8,enchanter of the ,north0 in the  
rare quality of story-telling1 for      
never was a tale more pleasantly told   
than 8,the ,legend of the ,sleepy       
,hollow40 ,neither is there a more      
exquisitely beautiful or sentimental    
fragment in all the heart-moving scenes 
drawn by that able and amiable  writer  
than ,irving's sketch of 8,the ,broken  
,heart40      ,,voyages ,,and           
,,discoveries ,,of    ,,the ,,companions
 ,,of ,,columbus4    ,by ,,washington   
,,irving4 ,with ,illustrations4    ,the 
extraordinary actions and adventures of 
these men may be said to  unite romance 
and truth4 ,chivalry had left the land1 
and launched  upon the deep in the ships
 of these ,spanish discoverers4         
,contempt  of danger1 and fortitude of  
suffering1 a passion for vain-glorious  
exploit1 and a bigoted zeal for the     
propagation of their faith1 are  the    
characteristics of these marine heroes4 
,the extravagant career of  the daring  

,ojeda1 particularly his adventures     
along the coast of ,terra  ,firma1 and  
the wild shores of ,cuba--the sad story 
of ,nicuessa--the  singular cruise of   
,juan ,ponce de ,leon1 who fell upon the
 coast of  ,florida1 in his search after
 an imaginary fountain of youth--and    
above  all1 the chequered fortunes of   
,vasco ,nunez de ,balboa1 whose         
discovery  of the ,pacific ,ocean forms 
one of the most beautiful and striking  
incidents in the history of the ,new    
,world1--are so many examples of        
knight-errantry upon the high seas4 ,the
 charm of ,mr4 ,irving's style has      
never been displayed more strikingly    
than in this little manual of true      
romance4      ,,the ,,universal         
,,history ,,from ,,the ,,creation ,,of  
,,the ,,world4    ,by ,,alexander       
,,fraser ,,tytler1 ,,lord               
,,woodhouselee4    #f ,vols4    ,perhaps
 few works in general literature were   
ever produced more  synthetically1 or   
with more vigilant caution than 8,the   

,universal  ,history40 ,mr4 ,gilpin     
requested his most learned and judicious
 friends  to criticize his ,,mss41 and  
for many years they were submitted to   
this  wholesome ordeal4 ,the ,universal 
,history at first appeared in the form  
of ,lectures1 and was received with the 
most entire approbation of  the         
students4 ,the sketch thus carefully    
made for oral delivery was  gradually   
filled up1 and the picture completed in 
every part4    ,the ,author's style is  
terse1 lucid1 and nervous1 and his plan 
not only  moral1 but more instructive   
than any hitherto pursued in treating of
  general history4      ,,the ,,life    
,,of ,,sir ,,isaac ,,newton4    ,by     
,,sir ,,david ,,brewster1 ,,ll4,d41     
,f4,r4,s4    ,portrait and ,woodcuts4   
,this is the only extended life of the  
greatest of ,english philosophers4  ,in 
attempting to fill up this gap in our   
philosophic and scientific  literature1 
,sir ,david ,brewster has not only      
sought out1 from resources  hitherto    

unknown1 every fresh and novel          
particular regarding his  life1 but has 
given the most lucid explanation of     
,newton's great  discoveries--and has   
endeavoured to render these intelligible
 to all  classes of readers4      ,a    
,,journal ,,of ,,the ,,plague ,,year4   
,by ,,daniel ,,de ,,foe4    ,a ,new     
,edition1 with ,historical ,notes by ,e4
 ,w4 ,,brayley1 ,f4,s4,a4    8,from ,de 
,foe's ,history of the ,plague we may   
derive more information  than from all  
the other publications on the subject   
put together4  ,he has collected all the
 facts attending the rise1 progress1 and
  termination of the malady2 an accurate
 report of the number of deaths1  as    
published by authority2 a faithful      
account of the regulations  adopted to  
arrest and mitigate its fury4 ,but that 
which imparts life  to the whole1 and   
forms its distinguishing feature1 is its
 descriptive  imagery4 ,the effects upon
 the affrighted minds of the inhabitants
 are  depicted with all the genuine     

pathos of nature1 without any aim at    
effect1 but with the ease and simplicity
 of real life40      ,a ,,classical     
,,tour ,,through ,,italy4    ,by the    
,,rev4 ,t4 ,,chetwode ,,eustace4        
,seventh ,edition4 ,with great          
,additions and ,translations of the     
various  ,quotations from ,ancient and  
,modern ,authors4 #c ,vols4    ,it was  
the fate of ,eustace1 like that of      
,bruce1 to see his labours  rejected1   
and his veracity impeached2 nor did     
these painful  insinuations originate in
 the chance of ignorance4 ,his honesty  
was also  called in question4 ,but truth
 in both instances eventually prevailed1
  and the writings of both these amiable
 but injured travellers are  now        
appealed to as standard works4          
,eustace's ,journey is not only the     
most accurate in topography1            
architecture1 and politics1 but is1  par
 excellence1 the classical tour through 
this land of poetry and  painting4      
,those tourists who would soar above    

,eustace1 have vainly  sought to        
depreciate his learning4 ,those whose   
lot was cast below him1  have gathered  
from his rich plumage2 but neither had  
the courage to  pass him by in silence4 
,in this edition1 which is sold at      
one-third the  cost of the earlier ones1
 the discoveries made by excavation     
since the  author's1 death have been    
introduced4      ,,the ,,eventful       
,,history ,,of    ,,the ,,mutiny ,,and  
,,piratical ,,seizure ,,of ,,the        
,,bounty4    ,by ,,john ,,barrow1 ,esq41
 ,secretary to the ,admiralty4 ,with    
,five ,plates  from ,original ,sketches4
    8,the ,author of this little volume 
has brought into one connected view     
what has hitherto appeared only in      
detached fragments--and some of  these  
not generally accessible--the historical
 narrative of an event  which deeply    
interested the public at the time of its
 occurrence1 and  from which the naval  
service in particular1 in all its ranks1
 may still  draw instructive and useful 

lessons4    8,the story in itself is    
replete with interest4 ,we are taught by
 the  ,book of ,sacred ,history1 that   
the disobedience of our first parents   
entailed on our globe of earth a sinful 
and a suffering race2 in  our time there
 has sprung up from the most abandoned  
of this sinful  family--from pirates1   
mutineers1 and murderers--a little      
society1  which1 under the precepts of  
that sacred volume1 is characterized  by
 religion1 morality1 and innocence4 ,the
 discovery of this happy  people1 as    
unexpected as it was accidental1 and all
 that regards their  condition and      
history1 partake so much of the         
romantic1 as to render  the story not   
ill-adapted for an epic                 
poem40--,author's ,preface4      ,,fairy
 ,,legends    ,,and ,,traditions ,,of   
,,the ,,south ,,of ,,ireland4    ,by ,t4
 ,,crofton ,,croker4 ,with numerous     
,cuts4    ,fairy ,tales epitomize the   
customs1 and manners1 and superstitions 
of  a people in by-gone times1 and are  

therefore valuable as auxiliary to  the 
interpretation of history4 ,mr4         
,croker's ,irish ,legends are rich  in  
that racy humour that characterizes his 
countrymen1 and appear to  have         
exhausted the traditionary treasures of 
the ,emerald ,isle4 ,the  ,illustrations
 are also redolent of ,hibernian wit and
 genius1--they are  spirited designs1   
and in the happiest manner of ,messrs4  
,brooke and  ,maclise1 with whose merits
 the public are familiar4      ,,the    
,,life ,,and ,,times ,,of ,,richard ,i4 
,,surnamed ,c,,ur-,,de-,,lion1 ,,king   
,,of ,,england4    ,by ,,william ,e4    
,,aytoun1 ,author of 8,bothwell10 a     
,poem4    ,none of our monarchs has     
achieved a wider fame than              
,cur-de-,lion1 yet  his personal history
 is of all others least studied or      
understood4  ,all men know that he      
rebelled against his father1 but        
comparatively  few are aware of the     
cause4 ,all know that he conducted a    
crusade1 and  encountered ,saladin2 but 

few are acquainted with the extent of   
his  conquests1 or the causes which     
drove him back a fugitive to ,europe4   
,no  period of the romantic ages is more
 interesting1 or better entitled to  a  
close examination4      ,,narratives    
,,of ,,peril ,,and ,,suffering4    ,by  
,r4 ,a4 ,,davenport4 #b ,vols4    ,this 
wide field for the display of taste1    
talent1 and general  acquaintance with  
the history of man in his social        
character1 has  been occupied by ,mr4   
,davenport1 a veteran in elegant        
literature2  and the popularity which   
his selections from the children of     
sorrow  has acquired1 is equal to that  
of his most successful labours4 ,in     
collecting so many tales of woe and of  
enterprise1 the author disclaims  the   
mere vanity of having produced a work of
 amusement2 he seeks  to inculcate the  
salutary lesson1 8that there are few    
things that  may not be accomplished by 
perseverance and courage1 accompanied by
  self-command and presence of mind40   

,,the ,,life ,,of ,,bruce1    ,,the     
,,african ,,traveller4    ,by ,major    
,sir ,,francis ,b4 ,,head1 ,author of   
8,rough ,notes10 c4    ,bruce's         
,travels1 as originally published1      
occupy five quarto volumes1  mixed up   
with ,abyssinian history1 and           
speculations on ,egyptian  mythology4   
,the author has contrived to compress   
into this little  volume the best parts 
of ,bruce's ,life and voluminous and    
expensive  ,travels1 without omitting   
one incident of importance and interest4
 ,he  has vindicated the character of   
,bruce1 by confronting the statements   
of his accusers with the testimony of   
later travellers4 ,the narrative  had   
been allowed universally to possess the 
interest of a romance1  from the graphic
 style in which he has described his    
adventures and  sufferings1 and the     
strange people and countries which he   
visited3 but  ,major ,head has secured  
for ,bruce the credit of a trustworthy  
authority1  in addition to the          

reputation of an entertaining narrator4 
,,the ,,court ,,and ,,camp ,,of         
,,buonaparte4    ,with a full-length    
portrait of ,prince ,talleyrand1 and    
other ,portraits4    ,this volume is a  
suitable and indispensable companion to 
the ,life of  ,napoleon4 ,it contains   
the cream 8of many hundred volumes10 in 
the  shape of ,memoirs1 ,lives1         
,narratives1 ,anecdotes1 c41 connected  
with  ,buonaparte1 with which the press 
of ,france has for fifteen years been   
teeming4 ,it presents rapid1 but        
vigorous sketches of the ,emperor's     
,brothers1 ,wives1 ,sisters1 ,ministers1
 ,marshals1 and ,generals2 and those    
who wish for competent knowledge of     
8,napoleon and his ,times10 will  find  
no work in the ,english language which  
conveys such information in  a more     
concise shape or a more lively manner4  
,,the ,,life ,,and ,,voyages ,,of       
,,christopher ,,columbus4    ,by        
,,washington ,,irving4 ,abridged by him 
from his larger ,work4 ,with            

,portraits1 ,maps1 c4    ,this little   
work has become a universal school-book 
in ,america4 ,it  contains all that is  
most important in the original1 in a    
form more  condensed1 and more within   
the reach of the general reader2 while  
the  story is told with the same spirit 
and grace as in the great work4 ,as  a  
book of entertainment1 it will bear     
comparison with any biographical  sketch
 of the age4      ,,lives ,,of ,,eminent
 ,,british ,,physicians4    ,with fine  
,portraits and ,woodcuts4    ,the ,lives
 of ,physicians furnish a theme by no   
means deficient in  interest and value4 
,from them have proceeded some of the   
greatest  benefactors of the human race2
 their history abounds in instances  of 
individuals1 who1 obscure and small1    
have1 by the vigour of their            
understanding and their perseverance1   
raised themselves among the  great of   
the land4 ,the memoirs of ,cullen1      
,hunter1 and ,baillie1 afford  striking 
examples of talent and perseverance     

triumphing in the midst of              
difficulties4    ,of the topics         
discussed in the course of this volume1 
the most  prominent are--,the ,discovery
 of the ,circulation of the ,blood1 by  
,harvey4 ,the ,sweating ,sickness in the
 time of ,edward ,,iii4 ,a ,sketch of   
the ,great ,plague of ,london1 in       
#affd-e4 ,jenner's invaluable ,discovery
  of ,vaccination4    ,to this edition  
the names of ,clutterbuck1 ,paris1      
,merriman1 ,chambers1  and ,halford1    
have been added4      ,,history ,,of    
,,new ,,york1    ,,from ,,the           
,,beginning ,,of ,,the ,,world ,,to     
,,the ,,end ,,of ,,the ,,dutch          
,,dynasty4    ,by ,,diedrich            
,,knickerbocker4 ,plates after          
,,cruikshank4    ,this is a satirical   
production1 in which the follies of the 
day are  humorously depicted in the     
persons and costume of the ancient      
,dutch  colonists who founded ,new      
,york4 ,the scene is local1 the         
application  directed to that city1 to  

recent occurrences in the history of the
  ,united ,states1 and of measures of   
the government of the ,model ,republic4 
,the satire1 however1 is not personal1  
but aimed at human character and        
conduct1 and may1 therefore1 be         
generally felt4      ,,lives ,,of       
,,individuals    ,,who ,,raised         
,,themselves ,,from ,,poverty ,,to      
,,eminence ,,or ,,fortune4    ,by ,r4   
,a4 ,,davenport4    ,the object of this 
work is not merely to inculcate a moral 
lesson to  youth1 but to encourage      
virtue generally by creating submission 
to the  law of opinion4 ,when mankind   
perceive meritorious exertions in every 
rank rewarded1 and in numerous instances
 crowned with success1 they are  more   
strongly supported in their resistance  
to difficulties1 and more  boldly       
encounter and conquer them4 ,this single
 volume includes the most  varied       
memoirs2 whence it will appear that     
industry and perseverance1  accompanied 
by rectitude of intention1 obtain their 

merited reward in  every civilized      
nation of our globe4      ,,history ,,of
 ,,the ,,mutiny ,,at ,,spithead ,,and   
,,the ,,nore4    ,by ,j4 ,,neale1 ,esq41
 ,author of 8,cavendish40    ,with an   
,inquiry into its ,origin and           
,treatment4 ,with a ,portrait of        
,,richard ,,parker4    ,resistance to   
authorities necessarily enlists so few  
abettors1 that1  even when it originates
 in cruelty1 injustice1 and injury1 its 
correction is demanded by the voice of  
the nation4 ,to this feeling must  be   
traced the flagrant partiality of our   
historians in describing the  ,mutiny of
 the ,nore1 and their misrepresentation 
of the causes of that  calamity4 ,viewed
 at this distance of time1 it is        
remembered as the  foundation of that   
splendid and perfect discipline which   
has ever since  pervaded and adorned the
 fleet1 and as the cause for abolishing 
the  despotic practice of impressment4  
,but from these memorable movements     
legislators may receive a lesson1 and   

learn how much more faithful  freemen   
are than slaves to a state in danger1   
and more binding the ties  of gratitude 
and affection than the terror of        
tyranny4 ,this is the  moral reduced    
from the ,mutiny of the ,nore in the    
present history4      ,,tour ,,through  
,,south ,,holland ,,and ,,up ,,the      
,,rhine4    ,with #aj ,views1 from      
,designs of ,,lieut4-,,col4 ,,batty4    
,it is strange that the history and     
condition of ,holland should be so      
little known1 and that it till now      
should never have been made the  subject
 of a popular work4 ,the object of this 
little book is not merely  to afford    
entertainment1 but to furnish that      
valuable and practical  information1    
which will render it a desirable        
guide-book to all who  are tempted to   
take a summer's trip across ,holland1 up
 the ,rhine1 and  through ,belgium2     
visiting ,rotterdam1 the ,hague1        
,amsterdam1 ,cologne1  ,coblentz1       
,frankfort1 ,brussels1 and ,antwerp4    

,,the ,,lives ,,of ,,scottish           
,,worthies4    ,by ,,patrick ,,fraser   
,,tytler1 ,esq4 #c ,vols4    8,truth is 
strange1 stranger than fiction40--,the  
romantic annals of  ,scotland1 and the  
characters of her ancient               
heroes--,wallace1 ,bruce1 and  the      
like1--will go far to convert this      
expression into an axiom4    ,,haddon1  
,,brothers1 ,,and ,,co41 ,,printers1    
,,castle ,,street1 ,,finsbury4          
99       99       99       99       99  
,transcriber's ,notes    ,obvious       
typographical errors have been silently 
corrected and  hyphenation has been     
standardised4 ,other variations in      
spelling and  punctuation remain        
unchanged4    ,italics are represented  
thus italic and bold thus bold4