,illustration3 ,,medallion ,,and        
,,autograph ,,from ,,monument ,,to      
,,philipp ,,reis ,,at ,,friedrichsdorf4 
,,philipp ,,reis3                       
,,inventor ,,of                         
,,the ,,telephone4                      
,a ,,biographical ,,sketch1             
,,with ,,documentary ,,testimony1       
,,translations ,,of ,,the               
,,original ,,papers ,,of ,,the          
,,inventor ,,and                        
,,contemporary ,,publications4          
,,by                    ,,silvanus ,p4  
,,thompson1 ,b4,a41 ,d4,sc41            
,,professor ,,of ,,experimental         
,,physics ,,in ,,university ,,college1  
,,bristol4                              
,illustration                           
,,london3                   ,e4  ,f4 ,n4
 ,,spon1 #af1 ,,charing ,,cross4        
,,new ,,york3 #ce1 ,,murray ,,street4   
#ahhc4     ,,preface4   ,the title of   
this little work sufficiently indicates 
its nature and scope4 ,the labour of    
preparing it has not been slight1 and   

has involved the expenditure of much    
time in prosecuting inquiries both in   
this country and in ,germany amongst the
 surviving contemporaries of ,philipp   
,reis4 ,to set forth the history of this
 long-neglected inventor and of his     
instrument1 and to establish upon its   
own merits1 without special pleading1   
and without partiality1 the nature of   
that much-misunderstood and much-abused 
invention1 has been the aim of the      
writer4 ,the thought that he might thus 
be of service in rendering justice to   
the memory of the departed worthy has   
inspired him to his task4 ,he has       
nothing to gain by making ,reis's       
invention appear either better or worse 
than it really was4 ,he has therefore   
preferred to let the contemporary       
documents and the testimony of          
eye-witnesses speak for themselves1 and 
has added that which seemed to him      
desirable in the way of argument in the 
form of four appendices4  ,the author's 
acknowledgments are due in an especial  

manner to ,mr4 ,albert ,stetson1 ,a4,m41
 of ,cohasset1 ,massachusetts1 who has  
given him much valuable assistance in   
the collection of information both in   
,germany and in this country1 and who   
has also assisted in the translation of 
some of the contemporary documents to be
 found in the work4 ,to the friends1    
acquaintances1 and pupils of ,philipp   
,reis1 and especially to the surviving  
members of the family at                
,friedrichsdorf1 who have most kindly   
furnished many details of information1  
the author would express his most       
cordial thanks4 ,the testimony now      
adduced as to the aim of ,philipp       
,reis's invention1 and the measure of   
success which he himself attained1 is   
such1 in the author's opinion1 and in   
the opinion1 he trusts1 of all          
right-thinking persons1 to place beyond 
cavil the rightfulness of the claim     
which ,reis himself put forward of being
 the inventor of the ,telephone4 ,full  
and sufficient as that testimony is1    

much more remains as yet unpublished4   
,the author has1 for example1 been      
permitted to examine a mass of evidence 
collected by the ,dolbear ,telephone    
,company1 which entirely corroborates   
that which is here presented4 ,it is1   
however1 for certain reasons beyond the 
author's control1 deemed well at the    
present moment to withhold this         
testimony for a little while from       
publication4 ,the appearance of this    
volume at the present time needs no     
apology from the author4 ,he is         
conscious that all he can do will add   
little or nothing to the lustre with    
which the name of ,philipp ,reis will be
 handed down to posterity4 ,when the    
,jubilee of ,philipp ,reis comes to be  
celebrated in #ahhd 7,january #gth71 the
 world will find out its indebtedness to
 the great man whose thoughts survive   
him4     ,,philipp ,,reis4     ,,chapter
 ,i4  ,,biography ,,of ,,the ,,inventor4
  ,compiled chiefly from papers left by 
the deceased1 and from the biographical 

notice of the late ,professor ,schenk4  
,philipp ,reis1 or1 as his full name    
appears from his autobiographical sketch
 to have been1 ,johann ,philipp ,reis1  
was born on the #gth of ,january1 #ahcd1
 at ,gelnhausen1 in the principality of 
,cassel4 ,his father1 who belonged to   
the ,evangelical ,church1 was a master  
baker1 but also pursued farming to some 
extent1 as the circumstances of small   
provincial towns generally require4 ,as 
his mother had died young1 his paternal 
grandmother undertook the bringing up of
 the boy4 8,while my father10 writes    
,herr ,reis1 8strove constantly to      
cultivate my mental powers by           
instruction concerning the things which 
surrounded me 7by discussing that which 
was actually observed71 my grandmother  
turned her activity to training my      
disposition and to the development of   
the religious sentiments to which she   
was eminently fitted by the experiences 
of a long life1 by being well-read1 and 
especially by her gift of narration40   

,on attaining his sixth year the boy was
 sent to the common school of his native
 town4 ,his teachers soon recognised    
that he possessed no ordinary           
endowments1 and sought to induce his    
father to entrust him later to a higher 
institution of learning4 ,his father    
agreed to this2 and the plan was to have
 been carried out after the boy had     
passed the middle-class of the common   
school4 ,how the father contemplated the
 carrying out of the plan is not known2 
he died ere the son had yet completed   
his tenth year4  ,as a considerable     
number of children from                 
,frankfort-on-the-,main and its         
neighbourhood1 attended that time       
,garnier's ,institute at                
,friedrichsdorf1 near ,homburg1 the idea
 occurred to his guardian and his       
grandmother to entrust the boy to this  
school4 ,he entered there when in his   
eleventh year4 8,the foreign languages1 
,english and ,french1 taught in the     
,institute1 attracted me specially4 ,the

 library of the ,institute1 rich and    
well chosen for its size1 gave my mind  
excellent nourishment40 ,at the end of  
his fourteenth year he had passed       
through the school1 organised as it then
 was1 and he now went to ,hassel's      
,institute at ,frankfort-on-the-,main4  
,his delight in the study of language   
induced him to learn ,latin and         
,italian4 ,and here1 also1 the taste for
 the study of natural sciences and      
mathematics appears to have been        
awakened in him4 ,the lively zeal with  
which he applied himself to both these  
disciplines induced his teachers to     
advise his guardian that he should allow
 the boy to attend the ,polytechnic     
,school at ,carlsruhe1 on finishing his 
course at the ,institute4 8,all the     
endeavours of my well-wishing teachers  
shattered themselves1 however1 against  
the will of one of my guardians1 who was
 also my uncle4 ,he wished that ,i      
should follow mercantile pursuits4444 ,i
 wrote him at that time that ,i should1 

indeed1 be obedient and learn the       
pursuit prescribed for me1 but that ,i  
should in any case continue my studies  
later40  ,on the #ast of ,march1 #ahej1 
,philipp ,reis entered the colour       
establishment of ,mr4 ,j4 ,f4           
,beyerbach1 of ,frankfort1 as an        
apprentice4 ,by diligence and           
punctuality he soon won the esteem of   
his principal4 ,all his leisure time he 
bestowed upon his further education4 ,he
 took private lessons in mathematics and
 physics1 and attended the lectures of  
,professor ,r4 ,bttger1 on ,mechanics1  
at the ,trade ,school4 ,and so the end  
of his apprenticeship arrived4 ,at the  
conclusion of it he entered the         
,institute of ,dr4 ,poppe1 in           
,frankfort4 8,several of my comrades in 
this establishment1 young people of     
sixteen to twenty years old1 found it1  
as ,i did1 a defect that no natural     
history1 history1 or geography1 was     
taught4 ,we determined1 therefore1 to   
instruct one another in these subjects4 

,i undertook geography1 and formed from 
this first occasion of acting as teacher
 the conviction that this was my        
vocation4 ,dr4 ,poppe confirmed me in   
this view and aided me by word and      
deed40  ,in the year #ahea1 whilst      
resident in ,frankfort1 ,reis had become
 a member of the ,physical ,society of  
that city4 ,this ,society1 which still  
flourishes1 then held1 and still        
continues to hold1 its meetings in the  
,senckenburg ,museum4 ,lectures in      
,chemistry and ,physics are delivered by
 resident professors in regular courses 
every week throughout the winter1 under 
the auspices of this ,society2 and every
 ,saturday evening is devoted to the    
exposition of recent discoveries or     
inventions in the world of physical     
science1 astronomy1 etc4 ,the most      
active members of this ,society during  
the time of ,reis's connection with it  
were the late ,professor ,bttger1       
,professor ,abbe 7now of ,jena71 and    
,dr4 ,oppel1 all of whom contributed    

many valuable original memoirs to the   
,jahresberichte1 or ,annual ,reports1   
published by the ,society4 ,amongst its 
corresponding and honorary members it   
counted the names of all the best       
scientific men of ,germany1 and also the
 names of ,professor ,faraday1          
,professor ,sturgeon1 and ,sir ,charles 
,wheatstone4 ,doubtless the discussion  
of scientific questions at this ,society
 greatly influenced young ,reis4 ,he    
remained for three years a member1 but  
dropped his connexion for a time on     
leaving ,frankfort4 ,he subsequently    
rejoined the ,society in the session of 
#ahfj-fa1 remaining a member until      
#ahfg1 when he finally resigned4  ,in   
the winter of #ahed-e we find him most  
zealously busied with preparations for  
carrying out his decision to become a   
teacher4 ,in #ahee1 he went through his 
year of military service at ,cassel4    
,returning to ,frankfort1 he worked away
 with his customary and marvellous      
energy1 attended lectures on mathematics

 and the sciences1 worked in the        
laboratory1 and studied books on        
,pedagogy4 8,thus prepared1 ,i set my   
mind on going to ,heidelberg in order to
 put the finishing touch to my education
 as teacher4 ,i wanted to settle down in
 ,frankfort in this capacity1 and       
undertake instruction in mathematics and
 science in the various schools4 ,then  
in the spring of #aheh1 ,i visited my   
former master1 ,hofrath ,garnier1 in    
whom ,i had ever found a fatherly       
friend4 ,when ,i disclosed to him my    
intentions and prospects1 he offered me 
a post in his ,institute4 ,partly       
gratitude and attachment1 and partly the
 ardent desire to make myself right     
quickly useful1 induced me to accept the
 proffered post40  ,in the autumn of the
 year #aheh he returned to              
,friedrichsdorf1 and in ,september #ahei
 he married and founded his peaceful    
home4  ,until ,easter1 #ahei1 he had but
 few lessons to give2 that he utilised  
every moment of his spare time most     

conscientiously in earnest activity and 
sound progress is nothing more than was 
to be expected from what has been said  
above4  ,it was during this time that   
,reis undertook the first experimental  
researches of an original nature4       
,working almost alone1 and without any  
scientific guide1 he was led into lines 
of thought not previously trodden4 ,he  
had conceived an idea that electrical   
forces could be propagated across space 
without any material conductor in the   
same way as light is propagated4 ,he    
made many experiments on the subject1   
the precise nature of which can never   
now be known1 but in which a large      
concave mirror was employed in          
conjunction with an electroscope and a  
source of electrification4 ,the results 
which he obtained he embodied in a      
paper1 of which no trace now remains1   
bearing as its title #8,on the          
,radiation of ,electricity4' ,this paper
 he sent in #ahei to ,professor         
,poggendorff for insertion in           

,poggendorff's well-known #8,annalen der
 ,physik4' ,greatly to his              
disappointment the memoir was not       
accepted by ,professor ,poggendorff4    
,its rejection was a great blow to the  
sensitive and highly strung temperament 
of the young teacher2 and as will be    
seen was not without its consequences4  
,the other piece of original work       
undertaken at this time was the research
 which resulted in his great            
invention--the ,telephone4 ,from the    
brief biographical notes written by the 
lamented inventor in #ahfh we extract   
the following3--  8,incited thereto by  
my lessons in ,physics in the year      
#ahfj1 ,i attacked a work begun much    
earlier concerning the organs of        
hearing1 and soon had the joy to see my 
pains rewarded with success1 since ,i   
succeeded in inventing an apparatus1 by 
which it is possible to make clear and  
evident the functions of the organs of  
hearing1 but with which also one can    
reproduce tones of all kinds at any     

desired distance by means of the        
galvanic current4 ,i named the          
instrument #8,telephon4' ,the           
recognition of me on so many sides1     
which has taken place in consequence of 
this invention1 especially at the       
,naturalists' ,association 7,versammlung
 ,deutscher ,naturforscher7 at ,giessen1
 has continually helped to quicken my   
ardour for study1 that ,i may show      
myself worthy of the luck that has      
befallen me40  ,his earliest telephones 
were made by his own hands1 in a little 
workshop behind his house1 whence he    
laid on wires into an upper room4 ,he   
also carried a wire from the physical   
cabinet of ,garnier's ,institute across 
the playground into one of the          
class-rooms for experimental telephonic 
communication2 and a firmly established 
tradition of the school is still        
preserved1 that the boys were afraid of 
making a noise in that class-room for   
fear ,herr ,reis should hear them in his
 place amongst his favourite            

instruments4  ,in #ahfb ,reis sent once 
again to ,professor ,poggendorff a      
memoir1 this time on the ,telephone4    
,this1 in spite of the advocacy of      
,professor ,bttger and of ,professor    
,mller of ,freiburg1 both of whom wrote1
 was declined by ,professor             
,poggendorff1 who treated the           
transmission of speech by electricity as
 a myth4 ,reis1 who was convinced that  
the rejection was because he was 8only a
 poor schoolmaster10 was more deeply    
pained than ever4  ,of the various      
public exhibitions of the ,telephone    
given by ,reis in the years #ahfa to    
#ahfd1 much will be found in the latter 
part of this book in which the          
contemporary notices are reprinted4 ,the
 first public lecture was in #ahfa1     
before the ,physical ,society of        
,frankfort 7see p4 #ej71 the last the   
above-mentioned occasion at ,giessen    
7see p4 #ic7 in #ahfd4 ,by this time    
,reis's invention was becoming widely   
known4 ,in addition to his own lectures 

on the subject1 the ,telephone had been 
the subject of lectures in various parts
 of ,germany4 ,it was lectured upon by  
,professor ,buff in ,giessen twice1 by  
,professor ,bttger both in ,frankfort   
and in ,stettin2 by ,professor ,h4      
,pick1 by ,professor ,osann of          
,wrtzburg1 by ,professor ,paul ,reis of 
,mainz1 and by others4 ,in #ahfc ,reis's
 ,telephone was shown by ,dr4 ,otto     
,volger1 ,founder and ,president of the 
,free ,german ,institute 7,freies       
,deutsches ,hochstift71 to the ,emperor 
of ,austria and to ,king ,max of        
,bavaria1 then on a visit to ,frankfort4
  ,telephones were being sent to various
 parts of the world4 ,they were to be   
found in the ,physical ,laboratories of 
,munich1 ,erlangen1 ,wiesbaden1 ,vienna1
 and ,cologne4 ,they were sent to       
distant parts of the world1 to          
,london1#a to ,dublin1 to ,tiflis in the
 ,caucasus4 ,in ,manchester1 before the 
,literary and ,philosophical ,society1  
,reis's ,telephone was shown in #ahfe by

 ,professor ,clifton1 who1 however1 from
 not having ,reis's own original memoirs
 on the subject before him1 utterly     
mistook--if the ,journal of ,proceedings
 be not in error--the nature of the     
instrument1 and not knowing the theory  
of vibration of the tympanum so         
beautifully demonstrated by ,reis1      
imagined the instrument to be a mere    
harmonic telegraph for transmitting code
 signals in fixed musical tones6        
,telephones1 too1 were becoming an      
article of commerce and1 good and bad1#b
 were being bought for the purpose of   
placing them in collections of          
scientific apparatus4 ,the invention    
was1 however1 too soon for the world4   
,to ,reis's great disappointment1 the   
,physical ,society of ,frankfort took no
 further notice of the invention1 the   
lustre of which shone upon them4 ,he    
resigned his membership in the ,society 
in ,october #ahfg4 ,the ,free ,german   
,institute of ,frankfort1 to which ,reis
 had next betaken himself1 though       

electing him to the dignity of honorary 
membership1 left the invention aside as 
a philosophic toy4 ,the ,naturalists'   
,assembly1 including all the leading    
scientific men of ,germany1 had indeed  
welcomed him at ,giessen2 but too late4 
,the sensitive temperament had met with 
too many rebuffs1 and the fatal disease 
with which he was already stricken told 
upon his energies4 ,in particular the   
rejection of his earlier researches had 
preyed upon his disposition4 ,it is     
narrated by eye-witnesses still living1 
how1 after his successful lecture on the
 ,telephone at ,giessen1 ,reis was asked
 by ,professor ,poggendorff1 who was    
present1 to write an account of his     
instrument for insertion in the         
#8,annalen1' to which request ,reis's   
reply was3 8,ich danke ,ihnen recht     
sehr1 ,herr ,professor2 es ist zu spt4  
,jetzt will ich nicht ihn schicken4     
,mein ,apparat wird ohne ,beschreibung  
in den ,annalen bekannt werden48        
,hmorrhage of the lungs and a loss of   

voice1 which eventually became almost   
total1 intervened to incapacitate him   
for work1 and especially from working   
with the telephone4 ,in #ahgc he        
disposed of all his instruments and     
tools to ,garnier's ,institute4 ,to     
,herr ,garnier he made the remark that  
he had showed the world the way to a    
great invention1 which must now be left 
to others to develop4 ,at last the end  
came4 ,the annual ,report of ,garnier's 
,institute for the academic year        
#ahgc-ahgd contains the following brief 
notice of the decease and labours of    
,philipp ,reis3--  8,at first active in 
divers subjects of instruction1 he soon 
concentrated his whole faculties upon   
instruction in ,natural ,science1 the   
subject in which his entire thought and 
work lay4 ,witnesses of this are not    
only all they who learned to know him in
 ,frankfort1 in the period when he was  
preparing for his vocation as teacher1  
but also his colleagues at the          
,institute1 his numerous pupils1 and the

 members of the ,naturalists'           
,association 7,naturforscher            
,versammlung7 at ,giessen1 who1         
recognising his keen insight1 his       
perseverance and his rich gifts1        
encouraged him to further investigations
 in his newly propounded theories4 ,to  
the ,association at ,giessen he brought 
his ,telephone4 ,to the ,association at 
,wiesbaden1 in ,september #ahgb1 he     
intended to exhibit a new ingeniously   
constructed gravity-machine1 but his    
state of health made it impossible4     
,this had become such during several    
years1 that he was enabled to discharge 
the duties of his post only by          
self-control of a special1 and1 as is   
generally admitted1 unusual nature2 and 
the practice of his vocation became more
 difficult when his voice also failed4  
,in the summer of #ahgc he was obliged1 
during several weeks1 to lay aside his  
teaching4 ,as by this rest and that of  
the autumn vacation an improvement in   
his condition occurred1 he acquired new 

hopes of recovery1 and resumed his      
teaching in ,october with his customary 
energy4 ,but it was only the last       
flickering up of the expiring lamp of   
life4 ,pulmonary consumption1 from which
 he had long suffered1 laid him in      
,december upon the sickbed1 from which  
after long and deep pains1 at five      
o'clock in the afternoon1 on the #adth  
of ,january1 #ahgd1 he was released by  
death40  ,the closing words of his      
autobiographical notes1 or 8curriculum  
vit10 as he himself styled them1 were   
the following3--  8,as ,i look back upon
 my life ,i can indeed say with the     
,holy ,scriptures that it has been      
#8labour and sorrow4' ,but ,i have also 
to thank the ,lord that ,he has given me
 ,his blessing in my calling and in my  
family1 and has bestowed more good upon 
me than ,i have known how to ask of     
,him4 ,the ,lord has helped hitherto2   
,he will help yet further40  ,in #ahgg1 
when the ,magneto-,telephones of ,graham
 ,bell began to make their way into     

,europe1 the friends of ,philipp ,reis  
were not slow to reclaim for their      
deceased comrade the honours due to him4
 ,in ,december #ahgg1 as the columns of 
the ,neue ,frankfurter ,presse show1 a  
lecture was given upon the history of   
the ,telephone1 at the ,free ,german    
,institute1 in ,frankfort1 by ,dr4      
,volger1 its ,president1 the same who in
 #ahfc had shown the ,telephone to the  
,emperor of ,austria4 ,on that occasion 
the ,telephone of ,reis's own           
construction1 presented by him to the   
,institute after his exhibition of it in
 #ahfb1 was shown4  ,early in #ahgh a   
subscription was raised by members of   
the ,physical ,society of ,frankfort for
 the purpose of erecting a monument to  
the memory of their former colleague4   
,this monument1 bearing a portrait      
medallion1 executed by the sculptor1    
,carl ,rumpf1 was duly inaugurated on   
,sunday1 ,december #h1 #ahgh1 when an   
appropriate address was pronounced by   
the late ,dr4 ,fleck1 of ,frankfort4    

,the #8,jahresbericht1' of the ,physical
 ,society for #ahgg-gh 7p4 #dd71        
contains the following brief record3--  
8,the ,society has erected to the memory
 of its former member1     the inventor 
of the ,telephone1 ,philipp ,reis       
7deceased in #ahgd71     teacher1 of    
,friedrichsdorf 7see #8,jahresbericht1' 
#ahfj-fa1 pp4     #eg-fd2 and #ahfa-fb1 
p4 #ac71 in the cemetery of that place1 
a monument which was inaugurated on the 
#hth of ,december1     #ahgh4 ,this     
monument1 an obelisk of red sandstone1  
bears in     addition to the dedication1
 a well-executed medallion portrait     
of ,philipp ,reis1 modelled by the      
sculptor1 ,a4 ,c4 ,rumpf1 and           
executed galvanoplastically by ,g4 v4   
,kress40  ,the inscription on ,reis's   
monument in the ,friedrichsdorf         
,cemetery is3--  ,illustration3         
,,hier ,,ruht                           
,,philipp ,,reis                        
,,geb4 #g4 ,,januar #ahcd               
,,gest4 #ad4 ,,januar #ahgd             

,,seinem ,,verdienstvollen              
,,mitgliede                             
,,dem ,,erfinder ,,des                  
,,telephons                        ,,der
 ,,physikalische ,,verein               
,,zu                                    
,,frankfurt-,a-,m4                      
,,errichtet                             
#ahgh    ,,principal ,,dates ,,in       
,,reis',s ,,life4    #ahcd  ,january #g 
,philipp ,reis born4    #ahej  ,march #a
        ,apprenticed to ,beyerbach4     
#ahee                 ,year of ,military
 ,service at ,cassel4    #aheh          
,settled in ,friedrichsdorf4    #ahei   
,september #ad   ,married4    #ahfj     
,invented the ,telephone4    #ahfa      
,october #bf     ,read ,paper 8,on      
,telephony by the                       
,galvanic ,current0 before the ,physical
                          ,society of   
,frankfort-on-the-,main4                
,november       ,read ,paper to the     
,physical ,society                      
of ,frankfort-on-the-,main1 entitled    

8,explanation of a new ,theory          
concerning the ,perception of ,chords   
and of ,timbre as a ,continuation       
and ,supplement of the ,report on       
the ,telephone40    #ahfa  ,december    
,wrote out his ,paper 8,on ,telephony10 
as printed in the #8,jahresbericht4'    
#ahfb  ,may #h          ,notice in      
#8,didaskalia' of ,reis's               
invention4         ,may #aa             
,lectured and showed the ,telephone     
to the ,free ,german ,institute         
7,freies ,deutsches ,hochstift7 in      
,frankfort-on-the-,main4                
,article on the ,telephone1 communicated
                          by ,inspector 
,von ,legat to the                      
,austro-,german ,telegraph ,society1    
and subsequently printed in its         
#8,zeitschrift' 7,journal74    #ahfc    
,july #d         ,showed his improved   
,telephone to                           
the ,physical ,society of               
,frankfort-on-the-,main4                
,september #f    ,reis's ,telephone     

shown to the ,emperor                   
of ,austria and the ,king of            
,bavaria1 then visiting ,frankfort4     
,sept4 #ag-bd    ,meeting of the        
8,deutscher ,naturforscher0             
at ,stettin2 ,reis's ,telephone         
shown there by ,professor               
,bttger4    #ahfd  ,february #ac        
,meeting of the 8,oberhessische         
,gesellschaft                           
fr ,natur- und ,heilkunde0              
at ,giessen2 ,lecture by                
,professor ,buff1 and exhibition by     
,reis of his ,telephone4                
,september #ba   ,meeting of the        
8,deutscher ,naturforscher0             
at ,giessen4 ,reis gave                 
an explanation of the ,telephone        
and the history of its invention1       
and exhibited it in action before       
the most distinguished scientific       
men of ,germany4    #ahgb  ,september   
,meeting of the 8,deutscher             
,naturforscher0                         
at ,wiesbaden2 ,reis                    

announced to show his 8,fallmaschine10  
but prevented by ill-health4    #ahgd   
,january #ad     ,philipp ,reis died4   
,illustration3 ,fig4 #a4 ,monument to   
,philipp ,reis in the ,cemetery at      
,friedrichsdorf4  ,,footnotes3  #a ,an  
autograph letter of ,philipp ,reis to   
,mr4 ,w4 ,ladd1 the well-known          
instrument maker of ,beak ,street1      
,london1 describing his telephone1 is   
still preserved1 and is now in          
possession of the ,society of ,telegraph
 ,engineers and ,electricians of        
,london4 ,it is reproduced at p4 #ha4   
#b ,as to the difference in quality of  
the instruments1 see the testimony of   
the maker1 ,albert of ,frankfort1 on p4 
#dd4 ,prof4 ,pisko 7see p4 #aja7 seems  
to have had a peculiarly imperfect      
instrument4     ,,chapter ,,ii4  ,,the  
,,inventor',s ,,apparatus4   ,in        
describing the various forms            
successively given by the inventor to   
his apparatus1 as he progressed1 from   
the earliest to the latest1 it will be  

convenient to divide them into two      
groups1 viz4 the ,transmitters and the  
,receivers4   ,a4--,reis's              
,transmitters4  ,so far as can be       
learned1 ,reis constructed transmitters 
in some ten or twelve different forms4  
,the complete series in this course of  
evolution does not now exist1 but the   
principal forms still remain and will be
 described in their historical order4   
,theoretically1 the last was no more    
perfect than the first1 and they all    
embody the same fundamental idea3 they  
only differ in the mechanical means of  
carrying out to a greater or less degree
 of perfection the one common principle 
of imitating the mechanism of the human 
ear1 and applying that mechanism to     
affect or control a current of          
electricity by varying the degree of    
contact at a loose joint in the circuit4
   ,first ,form4--,,the ,,model ,,ear4  
,naturally enough the inventor of the   
,telephone began with crude and         
primitive#c apparatus4 ,the earliest    

form of telephone-transmitter now       
extant1 was a rough model of the human  
ear carved in oak wood1 and of the      
natural size1 as shown in ,figs4 #b1 #c1
 #d1  #e4  ,illustration3 ,fig4 #b4     
,illustration3 ,fig4 #c4  ,illustration3
 ,fig4 #d4  ,illustration3 ,fig4 #e4    
,the end of the aperture a was closed by
 a thin membrane b1 in imitation of the 
human tympanum4 ,against the centre of  
the tympanum rested the lower end of a  
little curved lever c d1 of platinum    
wire1 which represented the 8hammer0    
bone of the human ear4 ,this curved     
lever was attached to the membrane by a 
minute drop of sealing-wax1 so that it  
followed every motion of the same4 ,it  
was pivoted near its centre by being    
soldered to a short cross-wire which    
served as an axis2 this axis passing on 
either side through a hole in a bent    
strip of tin-plate screwed to the back  
of the wooden ear4 ,the upper end of the
 curved lever rested in loose contact   
against the upper end g of a vertical   

spring1 about one inch long1 also of    
tin-plate1 bearing at its summit a      
slender and resilient strip of platinum 
foil4 ,an adjusting-screw1 h1 served to 
regulate the degree of contact between  
the vertical spring and the curved      
lever4 ,the conducting-wires by which   
the current of electricity entered and  
left the apparatus were connected to the
 screws by which the two strips of      
tin-plate were fixed to the ear4 ,in    
order to make sure that the current from
 the upper support of tin should reach  
the curved lever1 another strip of      
platinum foil was soldered on the side  
of the former1 and rested lightly       
against the end of the wire-axis1 as    
shown in magnified detail in ,fig4 #f4  
,if now any words or sounds of any kind 
were uttered in front of the ear the    
membrane was thereby set into           
vibrations1 as in the human ear4 ,the   
little curved lever took up these       
motions precisely as the 8hammer0-bone  
of the human ear does2 and1 like the    

8hammer0-bone1 transferred them to that 
with which it was in contact4 ,the      
result was that the contact of the upper
 end of the lever was caused to vary4   
,with every rarefaction of the air the  
membrane moved forward and the upper end
 of the little lever moved backward and 
pressed more firmly than before against 
the spring1 making better contact and   
allowing a stronger current to flow4 ,at
 every condensation of the air the      
membrane moved backwards and the upper  
end of the lever moved forward so as to 
press less strongly than before against 
the spring1 thereby making a less       
complete contact than before1 and by    
thus partially interrupting the passage 
of the current1 caused the current to   
flow less freely4 ,the sound waves which
 entered the ear would in this fashion  
throw the electric current1 which flowed
 through the point of variable contact1 
into undulations in strength4 ,it will  
be seen that this principle of causing  
the voice to control the strength of the

 electric current by causing it to      
operate upon a loose or imperfect       
contact1 runs throughout the whole of   
,reis's telephonic transmitters4 ,in    
later times such pieces of mechanism for
 varying the strength of an electric    
current have been termed                
current-regulators4#d ,it would not be  
inappropriate to describe the mechanism 
which ,reis thus invented as a          
combination of a tympanum with an       
electric current-regulator1 the         
essential principle of the electric     
current-regulator being the employment  
of a loose or imperfect contact between 
two parts of the conducting system1 so  
arranged that the vibrations of the     
tympanum would alter the degree of      
contact and thereby interrupt in a      
corresponding degree the passage of the 
current4  ,illustration3 ,fig4 #f4  ,mr4
 ,horkheimer1 a former pupil of ,reis1  
informs me that a much larger model of  
the ear was also constructed by ,reis4  
,no trace of this is1 however1 known4   

,second ,form4--,,tin ,,tube4  ,the     
second form1 a tube constructed by ,reis
 himself1 of tin1 is still to be seen in
 the ,physical cabinet of ,garnier's    
,institute1 at ,friedrichsdorf1 and is  
shown in ,fig4 #g4 ,it consists of an   
auditory tube a1 with an embouchure     
representing the pinna or flap of the   
ear4 ,this second apparatus shows also a
 great similarity with the arrangement  
of the ear1 having the pinna or         
ear-flap1 the auditory passage1 and the 
drum-skin 7a1 b1 c74 ,upon the bladder c
 there still remains some sealing-wax1  
by means of which a little strip of     
platinum1 for the all-essential         
loose-contact that controlled the       
current1 had formerly been cemented to  
the apparatus4  ,illustration3 ,fig4 #g4
   ,third ,form4--,,the ,,collar-,,box4 
,illustration3 ,fig4 #h4  ,the third    
form1 also preserved in the collection  
in ,garnier's ,institute1 is given in   
,fig4 #h1 which1 with the preceding1 is 
taken by permission from the pamphlet of

 the late ,professor ,schenk1 consists  
of a round tin box1 the upper part of   
which fits upon the lower precisely like
 the lid of a collar-box4 ,over this lid
 b1 which is #ae centimetres in         
diameter1 was formerly stretched the    
vibrating membrane1 there being also an 
inner flange of metal4 ,into a circular 
aperture below opened an auditory tube  
a1 with an embouchure representing the  
pinna4 ,the precise arrangements of the 
contact-parts of this apparatus are not 
known4 ,mr4 ,horkheimer1 who aided ,reis
 in his earlier experiments1 has no     
knowledge of this form1 which he thinks 
was made later than ,june #ahfb4 ,this  
is not improbable1 as the design with   
horizontal membrane more nearly         
approaches that of the tenth form1 the  
8,square-box0 pattern4   ,fourth        
,form4--,,the ,,bored-,,block4  ,the    
instrument described by ,reis in his    
paper 8,on ,telephony10 in the ,annual  
,report of the ,physical ,society of    
,frankfort-on-the-,main1 for #ahfj-fa   

7see p4 #ej71 comes next in order4 ,the 
inventor's own description of this      
telephone 7,fig4 #i7 is as follows3--   
,illustration3 ,fig4 #i4  8,in a cube of
 wood1 r s t u v w x1 there is a conical
 hole a1 closed at one side by the      
membrane b 7made of the lesser intestine
 of the pig71 upon the middle of which a
 little strip of platinum is cemented as
 a conductor or electrode4 ,this is     
united with the binding screw p4 ,from  
the binding screw n there passes        
likewise a thin strip of metal over the 
middle of the membrane1 and terminates  
here in a little platinum wire1 which   
stands at right-angles to the length and
 breadth of the strip4 ,from the        
binding-screw p a conducting wire leads 
through the battery to a distant        
station40 ,the identical apparatus used 
by ,reis was afterwards given by him to 
,professor ,bttger1 who later gave it to
 ,hofrath ,dr4 ,th4 ,stein1 of          
,frankfort1 from whose hands it has     
recently passed into the possession of  

the author of this work4 ,it possesses  
one feature not shown in the original   
cut1 viz4 an adjusting screw1 h1 which1 
so far as the writer can learn1 was put 
there by ,reis himself4 ,there appears  
no reason to doubt this1 since there was
 an adjusting screw in ,reis's very     
earliest form of transmitter1 the wooden
 ear4 ,a section of the actual          
instrument is given in ,fig4 #aj4       
,illustration3 ,fig4 #aj4   ,fifth      
,form4--,,the ,,hollow ,,cube4  ,another
 form1 a mere variety of the preceding1 
is described as follows by ,professor   
,bttger in his 8,polytechnisches        
,notizblatt0 7see p4 #fa73--  8,a little
 light box1 a sort of hollow cube of    
wood1 has a large opening at its front  
side and a small one at the back of the 
opposite side4 ,the latter is closed    
with a very fine membrane 7of pig's     
smaller intestine7 which is strained    
stiff4 ,a narrow springy strip of       
platinum foil1 fixed at its outer part  
to the wood1 touches the membrane at its

 middle2 a second platinum strip is     
fastened by one of its ends to the wood 
at another spot1 and bears at its other 
end a fine horizontal spike1 which      
touches the other little platinum strip 
where it lies upon the membrane40       
,sixth ,form4--,,the ,,wooden ,,cone4   
,illustration3 ,fig4 #aa4  ,another     
transmitter1 also a mere variety of the 
,fourth ,form1 has been described to me 
by ,herr ,peter1 of ,friedrichsdorf1 who
 assisted ,reis in his earlier          
experiments4 ,fig4 #aa is prepared from 
a rough sketch furnished me by the      
kindness of ,karl ,reis4 ,herr ,peter   
describes the apparatus as having been  
turned out of a block of wood by ,reis  
upon his own lathe4 ,the conical hole   
was identical with that of ,fig4 #i1 but
 the surrounding portions of the wood   
were cut away1 leaving a conical        
mouth-piece4   ,seventh                 
,form4--8,,hochstift0 ,,form4           
,illustration3 ,fig4 #ab4  ,the         
engraving presented below 7,fig4 #ab7   

has been engraved with the utmost       
fidelity by ,mr4 ,j4 ,d4 ,cooper1 from a
 photograph lent to the author by       
,ernest ,horkheimer1 ,esq41 of          
,manchester1 a former pupil of ,reis4   
,the original photograph was taken in   
#ahfb1 having been sent by ,reis in     
,june of that year to ,mr4 ,horkheimer1 
who had left for ,england4 ,the         
photograph was taken by ,reis himself   
with his own camera1 the exposure being 
managed by a slight movement of the     
foot1 actuating a pneumatic contrivance 
of ,reis's own invention1 which was     
originally designed to turn over the    
pages of a music book at the piano4     
,reis is here represented as holding in 
his hand the telephone with which he had
 a few days preceding 7,may #aa1 #ahfb7 
achieved such success at his lecture    
before the ,freies ,deutsches ,hochstift
 7,free ,german ,institute7 in          
,frankfort 7see p4 #ff74 ,this          
instrument was constructed by ,reis1    
young ,horkheimer assisting him in the  

construction4 ,mr4 ,horkheimer has very 
obligingly indicated from memory the    
form of the instrument--but dimly seen  
in the photograph--in a sketch from     
which ,fig4 #ac has been prepared4 ,mr4 
,horkheimer adds that the cone was a    
wooden one2 and that the square patch   
behind at the back was1 he thinks1 a box
 to contain an electro-magnet4          
,illustration3 ,fig4 #ac4   ,eighth     
,form4--,,lever ,,form4  ,illustration3 
,fig4 #ad4  ,the ,transmitter described 
with so much minuteness by ,inspector   
von ,legat in his ,report on ,reis's    
,telephone in #ahfb 7see p4 #gj71       
differs from the earliest and latest    
forms1 so much so that some have doubted
 whether this form was really invented  
by ,reis4 ,it is not described anywhere 
else than in ,legat's ,report 7in the   
8,zeitschrift0 of the ,austro-,german   
,telegraph ,union1 reprinted also in    
,dingler's ,journal71 except in ,kuhn's 
,handbook1 where1 however1 the          
description is taken from ,legat4       

,nevertheless a comparison of this      
instrument 7,fig4 #ad7 with the original
 model of the ear1 from which ,reis     
started1 will show that it embodies no  
new point4 ,there is1 first1 a conical  
tube to receive the sound1 closed at its
 end with a tympanum of membrane4 ,there
 is next a curved lever1 c d1 the lower 
end of which rests against the centre of
 the membrane4 ,thirdly1 there is a     
vertical spring1 g1 which makes contact 
lightly against the upper end of the    
curved lever4 ,lastly1 there is an      
adjusting screw4 ,it may be further     
pointed out that in each case the       
current enters 7or leaves1 as the case  
may be7 the lever at its middle point4  
,this form of transmitter is so closely 
allied indeed to the primitive 8ear0 as 
to be alike in every feature save the   
external form of the sound-gathering    
funnel4 ,the only reasonable doubt is   
not whether it be1 as ,legat asserts1   
,reis's transmitter1 but whether it     
ought not in chronological order to rank

 second4 ,legat's paper was not         
published1 however1 till #ahfb1 whilst  
the fourth form was described by ,reis  
in #ahfa4 ,no trace of any instrument   
corresponding in form to ,fig4 #ad1 save
 modern reproductions from ,legat's     
drawing1 has been found4 ,the instrument
 held by ,reis in his hand in the       
photograph 7,fig4 #ab7 is so strikingly 
like the form described by ,legat1 that 
it furnishes an additional reason for   
accepting ,legat's statement that this  
transmitter really is ,reis's invention4
  ,illustration3 ,fig4 #ae4             
,illustration3 ,fig4 #af4   ,ninth      
,form4--,,transitional ,,form4  ,our    
knowledge of this form is derived solely
 from information and sketches supplied 
by ,mr4 ,e4 ,horkheimer1 who assisted   
,reis in its construction4 ,figs4 #ae   
and #af are engraved after ,mr4         
,horkheimer's sketches4 ,the conical    
mouthpiece was of wood3 the contact     
pieces of platinum4 ,the point c was    
attached to a springy slip of brass1 g1 

fixed across the wooden box2 and the    
adjusting-screw1 h1 served to regulate  
the degree of initial pressure at the   
point of contact which controlled the   
current4   ,tenth ,form4--,,the ,,square
 ,,box4  ,illustration3 ,fig4 #ag4      
,illustration3 ,fig4 #ah4  ,the last    
form of ,reis's ,transmitter is that    
which has become best known1 being the  
only one 7except ,fig4 #i7 which found  
its way into the market4 ,it is here    
named1 for the sake of distinction1 as  
the 8,square ,box0 pattern4 ,it         
consisted of a square wooden box1 having
 a hinged lid4 ,fig4 #ag is reproduced  
from ,reis's 8,prospectus0 7see page    
#he71 whilst ,fig4 #ah is taken from    
,prof4 ,schenk's biographical pamphlet4 
,in this instrument the idea of the     
human ear is still carried out4 ,the tin
 funnel1 with its flaring embouchure1   
still represents the auditory tube and  
pinna4 ,the tympanum1 no longer at the  
very end of the tube1 is strained across
 a circular aperture in the lid4 ,upon  

it rests the strip of platinum foil     
which serves as an electrode1 and       
resting in loose contact with this lies 
the little angular piece of metal which 
,reis called the 8,hmmerchen40 ,above   
all lay a circular glass disk 7a cover  
to keep out the dust71 which was removed
 when the instrument was used4 ,so      
sensitive did this form prove itself    
that it was found unnecessary to speak  
right into the mouthpiece1 and the      
speaker in practice talked or sang with 
his mouth at some little distance       
vertically above the instrument2 a      
method which had the advantage of not so
 soon relaxing the membrane by the      
moisture of the breath4 ,the figures    
show also the auxiliary apparatus       
attached at the side1 consisting of a   
key for interrupting the circuit 7added 
at first to enable the experimenters to 
single out the 8galvanic tones0 from the
 reproduced tones1 and later applied1 as
 ,reis explains in his 8,prospectus10 on
 page #hg71 and an electro-magnet to    

serve as a 8call10 by which the listener
 at the other end could signal back to  
the transmitter4  ,this form of         
instrument1 which has been so frequently
 described in the ,text-books of        
,physics1 was constructed for sale first
 by ,albert of ,frankfort1 later by     
,ladd of ,london1 ,knig of ,paris1 and  
,hauck of ,vienna4 ,further details     
concerning it will be found in this     
book1 in ,reis's 8,prospectus10 and in  
other contemporary documents4  ,although
 this form is the one most commonly     
referred to as 8the ,reis ,telephone10  
it is evident from a consideration of   
the entire group of forms that ,reis's  
invention was in no way limited to one  
individual pattern of instrument4 ,for  
in all these forms there was embodied   
one all-embracing principle2--that of   
controlling the electric current by the 
voice working upon a point of imperfect 
contact1 by the agency of a tympanum1   
thereby opening or closing the circuit  
to a greater or less degree1 and so     

regulating the flow of the current4     
,b4--,reis's ,receivers4   ,first       
,form4--,,the ,,violin ,,receiver4      
,illustration3 ,fig4 #ai4  ,the first   
form of apparatus used by ,reis for     
receiving the currents from the         
transmitter1 and for reproducing audibly
 that which had been spoken or sung1    
consisted of a steel knitting-needle1   
round which was wound a spiral coil of  
silk-covered copper-wire4 ,this wire1 as
 ,reis explains in his lecture 8,on     
,telephony10 was magnetised in varying  
degrees by the successive currents1 and 
when thus rapidly magnetised and        
demagnetised1 emitted tones depending   
upon the frequency1 strength1 etc41 of  
the currents which flowed round it4 ,it 
was soon found that the sounds it       
emitted required to be strengthened by  
the addition of a sounding-box1 or      
resonant-case4 ,this was in the first   
instance attained by placing the needle 
upon the sounding-board of a violin4 ,at
 the first trial it was stuck loosely   

into one of the f-shaped holes of the   
violin 7see ,fig4 #ai73 subsequently the
 needle was fixed by its lower end to   
the bridge of the violin4 ,these details
 were furnished by ,herr ,peter1 of     
,friedrichsdorf1 music-teacher in       
,garnier's ,institute1 to whom the      
violin belonged1 and who gave ,reis1    
expressly for this purpose1 a violin of 
less value than that used by himself in 
his profession4 ,reis1 who was not      
himself a musician1 and indeed had so   
little of a musical ear as hardly to    
know one piece of music from another1   
kept this violin for the purpose of a   
sounding-box4 ,it has now passed into   
the possession of ,garnier's ,institute4
 ,it was in this form that the          
instrument was shown by ,reis in        
,october #ahfa to the ,physical ,society
 of ,frankfort4   ,second ,form4--,,the 
,,cigar-,,box ,,receiver4               
,illustration3 ,fig4 #bj4  ,later a     
shallow rectangular wooden box was      
substituted for the violin1 and the     

spiral was laid horizontally upon it    
7,fig4 #bj74 ,the date when this        
modification was made was either at the 
end of #ahfa or the early spring of     
#ahfb4 ,a cigar-box was the actual      
sounding-box1 and the needle was        
supported within the coil1 but not      
touching it1 with its ends resting upon 
two wooden bridges4   ,third            
,form4--,,the ,,electro-,,magnet        
,,receiver4  ,though the precise history
 of this form of telephonic receiver is 
defective1 there can be little doubt    
that it was conceived by ,reis amongst  
his earliest researches4 ,when there    
were in common use so many electric and 
telegraphic instruments in which an     
electro-magnet is employed to move an   
armature to and fro1 it is not          
surprising that ,reis should have       
thought of availing himself of this     
method for reproducing the vibrations of
 speech4 ,speaking of the two parts of  
his invention1 the ,transmitter and the 
,receiver1 ,reis himself says3#e 8,the  

apparatus named the #8,telephone1'      
constructed by me1 affords the          
possibility of evoking sound-vibrations 
in every manner that may be desired4    
,electro-magnetism affords the          
possibility of calling into life at any 
given distance vibrations similar to the
 vibrations that have been produced1 and
 in this way to give out again in one   
place the tones that have been produced 
in another place40 ,a remark1 almost    
identical with this1 is also made by    
,inspector von ,legat 7see p4 #gd7 in   
his ,report on ,reis's ,telephone4 ,it  
may be here remarked that the form of   
this receiver is known only from the    
figure and description given in that    
,report1 and from the extract therefrom 
printed in ,kuhn's #8,handbook' 7see p4 
#aji74 ,reis seems to have very soon    
abandoned this form1 and to have        
returned to the needle1 surrounded by a 
coil1 in preference to the              
electro-magnet4 ,the electro-magnet form
 is1 however1 of great importance1      

because its principle is a complete and 
perfect anticipation of that of the     
later receivers of ,yeates1 of ,gray1   
and of ,bell1 who each1 like ,reis1     
employed as receiver an electro-magnet  
the function of which was to draw an    
elastically mounted armature backwards  
and forwards1 and so to throw it into   
vibrations corresponding to those       
imparted to the transmitting apparatus4 
,fig4 #ba shows the disposition of the  
electro-magnet1 and of its vibratory    
armature upon a sounding-board4 ,this   
apparatus was a good deal larger than   
most of ,reis's instruments4 ,the       
sounding-board was nearly a foot long3  
the coils of the electro-magnet were six
 inches long1 and over an inch thick4   
,the armature1 a rod of iron of         
elliptical section1 was affixed         
cross-wise at the end of a 8light and   
broad0 vertical lever1 about seven      
inches long1 which seems to have been   
made of wood1 as in ,legat's ,report it 
is also denominated as a 8plank0        

7,balken74  ,illustration3 ,fig4 #ba4   
,fourth ,form4--,,the                   
,,knitting-,,needle ,,receiver4         
,illustration3 ,fig4 #bb4               
,illustration3 ,fig4 #bc4  ,the final   
form adopted by ,reis for his           
,reproducing-apparatus is that commonly 
known as the ,knitting-needle ,receiver4
 ,it differs only from the first form in
 that the needle and its surrounding    
spiral no longer stand upright on a     
violin1 but lie horizontally upon a     
rectangular sounding-box of thin pine   
wood4 ,the coil of silk-covered copper  
wire is wound upon a light wooden       
bobbin1 instead of being twisted round  
the needle itself4 ,two wooden bridges  
stand upon the sounding-box1 and through
 these pass the protruding ends of the  
needle1 whilst an upper box or lid1     
hinged to the lower at the back1 is     
added above4 ,figs4 #bb and #bc show    
this form1 the former being reproduced  
from ,reis's own ,prospectus 7see p4    
#he71 the latter being from             

,mller-,pouillet's #8,text-book of      
,physics' 7see p4 #ie74 ,herr ,albert1  
mechanician1 of ,frankfort1 who made and
 sold the ,reis telephones1 says that   
the upper box was added at his          
suggestion4 ,originally it was so       
constructed 7see ,fig4 #bb71 that when  
closed it pressed upon the steel needle4
 ,in the instruments of later date1 the 
notches which fitted over the needle    
were cut so deeply 7see ,fig4 #bc71 that
 the lid did not press upon the wire4   
,reis's own instructions are 7see p4    
#hf7 that the sound is intensified by   
firmly pressing the lid against the     
needle1 as was done occasionally by the 
listeners who pressed their ears against
 the lid in order to hear more          
distinctly4 ,the little key seen at the 
end of the sounding-box1 in ,fig4 #bb1  
was used for interrupting the current   
and so to telegraph back signals to the 
transmitter4  ,,footnotes3  #c ,dr4     
,messel1 ,f4,c4,s41 a former pupil of   
,reis1 and an eye-witness of his early  

experiments1 makes1 in a letter to      
,professor ,w4 ,f4 ,barrett1 the        
following very interesting statement3   
8,the original telephone was of a most  
primitive nature4 ,the transmitting     
instrument was a bung of a beer-barrel  
hollowed out1 and a cone formed in this 
way was closed with the skin of a       
,german sausage1 which did service as a 
membrane4 ,to this was fixed with a drop
 of sealing-wax a little strip of       
platinum corresponding to the hammer of 
the ear1 and which closed or opened the 
electric circuit1 precisely as in the   
instruments of a later date4 ,the       
receiving instrument was a knitting     
needle surrounded with a coil of wire   
and placed on a violin to serve as a    
sounding board4 ,it astonished every one
 quite as much as the more perfect      
instruments of ,bell now do4 ,the       
instrument ,i have described has now    
passed into the hands of the ,telegraph 
,department of the ,german ,government40
 ,the instrument now in the museum of   

the ,reichs ,post-,amt in ,berlin is not
 this1 but is the first of the          
8,improved0 ,telephones described later 
by ,reis in his 8,prospectus0 7see p4   
#he71 and is stamped 8,philipp ,reis10  
8#ahfc10 8,no4 #a40 ,s4,p4,t4  #d ,or   
sometimes 8tension-regulators10 though  
the latter term is acknowledged by most 
competent electricians to be            
indescriptive and open to objection4  #e
 ,see ,die ,geschichte und ,entwickelung
 des ,elektrischen ,fernsprechwesens    
7issued officially from the ,imperial   
,german ,post-office1 #ahhj71 p4 #g4    
,,chapter ,,iii4  ,,the ,,claim ,,of    
,,the ,,inventor4   ,in the present     
century1 when so many facilities exist  
for the diffusion of knowledge1 and when
 every new discovery and invention is   
eagerly welcomed and immediately noised 
abroad to every country of the globe1 it
 is hard to believe that the inventor of
 an instrument of the highest scientific
 value1 destined to play an important   
part in social and commercial life1     

should have been suffered to live and   
die in unrecognised obscurity4 ,still   
harder is it to believe that his        
invention passed into almost complete   
oblivion1 unacknowledged by most of the 
leading scientific men of his day and   
generation4 ,but hardest of all is it to
 believe that when at last attempts were
 made to give to him1 whose name and    
fame had thus been permitted to         
languish1 the credit of the splendid    
researches in which he wore his life    
away1 those attempts could be met on the
 one hand by an almost complete apathy1 
and on the other by a chorus of denial1 
not only that any such invention was    
made1 but that the inventor had ever    
intended to invent anything of the kind4
 ,yet nothing less than this has        
happened4 ,philipp ,reis1 the inventor  
of the ,telephone1 the first to scheme1 
and carry out into execution1 an        
instrument for conveying to a distance  
by means of electric currents the tones 
of human speech and human song1 is no   

longer amongst the living4 ,he cannot   
reclaim for himself the honours that    
have been showered upon the heads of    
others1 who1 however worthy of those    
honours they were--none will deny       
that--were only not the first to deserve
 them4 ,in his quiet grave1 in the      
obscurity of the ,german village where  
his daily work was done1 he sleeps      
undisturbed by the strife of tongues4   
,to him it matters nothing now1 whether 
his genius be recognised and his        
invention applauded1 or whether         
ignorance1 and calumny1 and envy1 alike 
decry both4 ,nevertheless1 the memory of
 him and of his work will live1 and will
 descend to posterity as of one whom his
 own generation knew not1 whose peculiar
 greatness passed unheeded save by a    
chosen few4 ,nor will posterity be the  
less ready to accord honour to him who  
in his own day could not even obtain    
justice4 ,yet something more than a mere
 historic justice for the poor          
schoolmaster of ,friedrichsdorf does the

 world owe2 justice to the great        
invention that is now imperishably      
associated with his name3 justice to the
 struggling family whom1 instead of     
enriching1 it impoverished2 and1 not    
least1 the justice of patience1 whilst  
the story of his life and work1 and the 
words he himself has written thereupon1 
are unfolded4  ,the point at issue1 and 
for which justice has been invoked1 and 
of which ample proof is given in these  
pages1 is not whether ,philipp ,reis    
invented a telephone--that is not       
denied--but whether ,philipp ,reis      
invented the ,telephone4 ,the irony of  
fate1 not to say the curious ignorance  
which is often called by a less polite  
name1 has decreed by the mouth of       
popular scientific writers1 of eminent  
engineers1 and of accomplished          
barristers1 that ,reis's invention was  
not an instrument for transmitting human
 speech at all--was not intended even   
for this--that it was a purely musical  
instrument in its inception1 and that it

 has always so remained4 ,these clever  
persons begin to persuade themselves of 
this view1 and forthwith invent a       
question-begging epithet1 and dub the   
instrument as a mere 8tone-telephone06  
,if some unprejudiced person ventures to
 speak of ,reis's instrument as having1 
as a matter of history1 transmitted     
speech1 all the contemptuous reply that 
he gets from the eminent somebody1 who  
poses as an authority for the moment1   
is3 ,oh1 but1 you know1 it was only a   
tone-telephone1 a musical toy1 and when 
some one was singing to it you fancied  
you caught the words of the song which1 
during singing1 were occasionally       
projected along with the music4 ,i've   
always regarded the accounts of its     
transmission of speech as a good joke2  
all it could possibly do was            
occasionally to utter an articulate     
noise in combination with a musical     
tone4 ,besides1 you know1 ,mr4 ,reis was
 a musical man1 who only intended it to 
sing1 and if it spoke it only spoke by  

accident2 but such an accident never did
 or could occur1 because the            
construction of it shows that it not    
only did not but could not transmit     
speech4 ,if ,mr4 ,reis had really       
penetrated the fundamental principle of 
the articulating telephone1 he would    
have arranged his instruments very      
differently2 and then1 you know1 if he  
really had transmitted speech the       
discovery would have attracted so much  
attention at the time4 ,moreover1 if he 
had meant it to talk1 he would have     
called it the articulating telephone1   
and not a telephone for transmitting    
tones1 you know2 no one before ,graham  
,bell ever dreamed of using a tympanum  
to catch articulate sounds1 or had he   
done so he would have been laughed at4  
,to all such clap-trap as this--and     
there has been enough ad nauseam of     
such--the one reply is silence1 and a   
mute appeal to the original writings of 
,reis and his contemporaries1 and to the
 tangible witness of inexorable         

scientific facts4 ,all the most         
important of these will be found in     
their appropriate places4 ,they amply   
establish the following points3--       
,i4--,reis's ,telephone was expressly   
intended to transmit speech4            
,,ii4--,reis's ,telephone1 in the hands 
of ,reis and his contemporaries1 did    
transmit speech4  ,,iii4--,reis's       
,telephone will transmit speech4        
,before proceeding to discuss these     
three points we will pause for a moment1
 first to clear away a lurking verbal   
fallacy1 then to point out the partial  
historic acknowledgment already conceded
 to ,reis's claims4  ,reis did not call 
his instrument an 8articulating         
telephone40 ,neither did he call it a   
8tone telephone40 ,he called it simply  
8,the ,telephone0 7,das ,telephon71#f as
 will be seen in his own first memoir   
7p4 #eg74 ,he did speak of his          
instrument again and again as an        
instrument 8for reproducing tones40 ,but
 it must be remembered that the ,german 

word ,ton 7plural ,tne7 used by ,reis is
 more nearly equivalent to our ,english 
word 8sound10 and includes articulate as
 well as musical tones1 unless the      
context expressly indicates otherwise4  
,so that when ,reis talked of the       
,reproduction of ,tones he was using    
words which did not limit his meaning to
 musical tones1 as indeed his memoirs   
show in other ways4 ,he started from a  
consideration of the mechanical         
structure of the human ear1 and         
endeavoured to construct an instrument  
on those lines because the ear can take 
up all kinds of tones4 ,reis was not so 
foolish as to imagine that the          
construction of the human ear was solely
 designed for musical1 to the exclusion 
of articulate tones4 ,we are not aware  
that the epithet1 ,tone-,telephone1 was 
ever applied to ,reis's instruments     
until it became advisable767 to seek a  
means of disparaging an old invention in
 order to exalt a new one4 ,and it is a 
curious point that the true musical     

8tone-telephones10 i4e4 instruments     
designed expressly to transmit specific 
musical tones for the purpose of        
multiple telegraphy1 were invented 7by  
,varley1 ,gray1 ,la ,cour1 ,graham      
,bell1 and ,edison7 long after ,reis's  
,telephone1 between the years #ahgj and 
#ahgf4 ,all these were dependent        
practically upon the tuning-fork system 
of vibration1 whereas ,reis's system was
 based on the tympanum of the ear4 ,to  
classify ,reis's invention with these   
would be absurd4  ,having shown the     
fallacy bound up in the term            
8tone-telephone10 we will dismiss the   
point with the remark that henceforth it
 will be a waste of time to argue with  
any person who applies that             
question-begging epithet to ,reis's     
invention4  ,partial historic           
acknowledgments of ,reis's claims as    
inventor of ,the ,telephone have been   
made from time to time by those best    
qualified to speak4  ,mr4 ,edison1 the  
inventor of the famous lamp-black button

 transmitter1 which he christened later 
as 8,the ,carbon ,telephone10 has       
himself stated in his account of his    
inventions1#g that he was started upon  
this line of investigation by having put
 into his hand1 by the late ,hon4 ,mr4  
,w4 ,orton1 a manuscript translation of 
,legat's ,report on ,reis's ,telephone1 
given in the ,journal of the            
,austro-,german ,telegraph ,union 7see  
,translation1 p4 #gj74 ,so that he was1 
therefore1 aware at least of this3 that 
in ,reis's instruments 8single words    
uttered1 as in reading1 speaking1 and   
the like1 were perceptible indistinctly1
 nevertheless1 here also the inflexions 
of the voice1 the modulations of        
interrogation1 exclamation1 wonder1     
command1 etc41 attained distinct        
expression40 ,so far as ,mr4 ,edison is 
concerned1 therefore1 ,reis is his      
starting-point by his own direct avowal4
  ,professor ,graham ,bell has not      
failed to acknowledge his indebtedness  
to ,reis1 whose entry 8into the field of

 telephonic research0 he explicitly     
draws attention to by name1 in his      
8,researches in ,electric ,telephony10  
read before the ,american ,academy of   
,sciences and ,arts1 in ,may #ahgf1 and 
repeated almost verbatim before the     
,society of ,telegraph ,engineers1 in   
,november #ahgg4 ,in the latter1 as     
printed at the time1 ,professor ,bell   
gave references to the researches of    
,reis1 to the original paper in         
,dingler's #8,polytechnic ,journal' 7see
 ,translation1 p4 #fa72 to the          
particular pages of ,kuhn's volume in   
,karsten's #8,encyclopdia' 7see p4      
#ajf71 in which diagrams and            
descriptions of two forms of ,reis's    
,telephone are given2 and where mention 
is also made of the success with which  
exclamatory and other articulate        
intonations of the voice were           
transmitted by one of these instruments2
 and to ,legat's ,report1 mentioned     
above 7and given in full on p4 #gj74    
,professor ,bell has1 moreover1 in      

judicial examination before one of the  
,united ,states ,courts expressly and   
candidly stated1#h that whilst the      
receivers of his own early              
tone-telephones were constructed so as  
to respond to one musical note only1 the
 receiver of ,reis's instrument1 shown  
in ,legat's ,report 7as copied in       
,prescott's #8,speaking ,telephone1' p4 
#aj71 and given on p4 #aji of this work1
 was adapted to receive tones of any    
pitch1 and not of one tone only4 ,it is 
further important to note that in       
,professor ,bell's ,british ,patent he  
does not lay claim to be the inventor1  
but only the improver of an invention3  
the exact title of his patent is1       
8,improvements in ,electric ,telephony  
7,transmitting or causing sounds for    
,telegraphing ,messages7 and ,telephonic
 ,apparatus40  ,so far as ,professor    
,bell is concerned1 therefore1 he is    
guiltless of stigmatising the ,reis     
instrument as a mere 8tone-telephone40  
,professor ,dolbear1 the inventor of the

 8,static ,receiver0 form of ,telephone1
 is still more explicit in avowing      
,reis's claim4 ,in the report of his    
paper on 8the ,telephone10 read1 ,march 
#ahhb1 before the ,society of ,telegraph
 ,engineers and of ,electricians#i we   
find3 8,the speaker could testify that  
the instrument would talk1 and would    
talk well4 ,the identical instruments   
employed by ,reis would do that1 so that
 ,reis's transmitters would transmit4   
,secondly1 his receiver would receive2  
and ,reis did transmit and receive      
articulate speech with such             
instruments40  ,as far as ,professor    
,dolbear is concerned1 therefore1 he    
admits in unequivocal terms the whole   
claim of ,reis to be the inventor of    
,the ,telephone4  ,count du ,moncel1    
author of a work on the ,telephone1     
which has run through several editions1 
though he has classified ,reis's        
instrument as a mere 8tone-telephone10  
has recently admitted#aj that he was1   
until the year #ahhb1 ignorant of some  

of ,reis's instruments and of his       
original papers4 ,he has1 moreover1     
added these words3 8,nevertheless1 it   
would not be just not to acknowledge    
that the ,reis ,telephone formed the    
starting-point of all the others20 also 
these significant lines3 8,it is        
probable that in this matter1 as in the 
greater number of modern inventions1 the
 original inventor obtained only        
insignificant results1 and that it was  
the man who first succeeded in arranging
 his apparatus so as to obtain really   
striking results that received the      
honour of the discovery and rendered it 
popular40  ,so far as the ,count du     
,moncel is concerned1 therefore1 the    
claims of ,philipp ,reis to be the      
inventor of the telephone are admitted1 
though hesitatingly1 to be historically 
just4  ,we now return to the proof of   
the three points previously enunciated4 
,i4--,reis's ,telephone was expressly   
intended to transmit speech4  ,reis's   
first instrument was 7see p4 #af7       

nothing else than a model of the        
mechanism of the human ear4 ,why did he 
choose this fundamental type which runs 
through all his instruments from first  
to last8 ,the reason is given in his own
 first memoir 7p4 #ea71 8,how could a   
single instrument reproduce at once the 
total actions of all the organs operated
 in human speech8 ,this was ever the    
cardinal question40 ,reis constructed   
his instrument therefore with intent to 
reproduce human speech4 ,for this reason
 he borrowed from the ear the suggestion
 of a tympanum4 ,of the operation of the
 tympanum he had the most exact and     
perfect conception4 ,he says 7p4 #ed71  
8,every tone1 and every combination of  
tones0--and this includes articulate    
tones1 of course1 and is just as true of
 them as of any other kind--8evokes in  
our ear1 if it enters it1 vibrations of 
the drum-skin1 the motions of which may 
be represented by a curve40 ,and        
further3 8,as soon1 therefore1 as it    
shall become possible1 at any place and 

in any prescribed manner1 to set up     
vibrations whose curves are like those  
of any given tone1 or combination of    
tones1 we shall then receive the same   
impression as that tone or combination  
of tones would have produced upon us40  
,again1 it is clear that his study of   
acoustics led him to employ the         
tympanum1 because of its special value  
in responding to all the complex        
vibrations of human speech4 ,it is no   
less significant that when a decade     
later ,varley1 ,gray1 and ,bell1 set    
themselves to invent tone-telephones for
 the purpose of multiple telegraphy1    
they abandoned tympanums as being       
unsuitable for tone-telephones1 and in  
lieu thereof employed vibrating tongues 
like those of tuning-forks4 ,reis's use 
of the tympanum had a very definite     
meaning then2 it meant nothing less than
 this3 ,i intend my instrument to       
transmit any sound that a human ear can 
hear4 ,that it was explicitly within his
 intention to transmit speech is        

confirmed by another passage of his     
first memoir 7p4 #eh71 wherein he       
remarks with a shade of disappointment  
that though 8the consonants are for the 
most part tolerably distinctly          
reproduced1 the vowels are not yet to an
 equal degree40 ,to his own pupils and  
co-workers he communicated his ideas4   
,one of the former1 ,mr4 ,e4            
,horkheimer1 now of ,manchester1        
expressly says 7see p4 #aag7 that       
,reis's intention was to transmit       
speech1 and that the transmission of    
music was an afterthought adopted for   
the convenience of public exhibition1   
just as was the case with the public    
exhibitions of ,bell's ,telephone       
fifteen years later4  ,nor did this     
imperfection cause ,reis to hide his    
intentions from the world4 ,he modestly 
claimed such success as he had obtained1
 and left the rest4 ,in #ahfc he drew up
 a ,prospectus 7given in extenso on p4  
#he71 which was printed to accompany the
 instruments which were sold2 and of    

which copies are still extant4 ,in this 
document he says3 8,besides the human   
voice1 according to my experience1 there
 can also be reproduced the tones of    
good organ pipes1 from ,f to c'''1 and  
those of a piano40 ,in this same        
,prospectus 7p4 #hg7 occur the          
instructions for the use of the signal  
call by which the listener communicates 
his wishes to the speaker4 ,those       
instructions run3 8,one beat  sing2 two 
beats  speak40 ,can any sane person     
doubt that ,reis intended his instrument
 to transmit speech1 when such          
directions stand printed in his own     
,prospectus8 ,legat's ,report 7#ahfb7   
speaks of ,reis's instrument as intended
 7see p4 #gg7 to speak1 and further     
describes the use of an elliptic cavity 
to which the listener can apply his ear4
 ,kuhn 7#ahff7 7see p4 #ajf7 says that  
the square-box transmitter 7,figs4 #ag1 
#ah7 did not send speech well1 and      
complains that he could only get from it
 an indistinguishable noise4 ,doubtless 

he spoke too loudly1 ,pisko 7#ahfe7     
speaks of the ,reis instrument as       
intended for speaking 7p4 #aje74        
,further1 in the letter which ,reis     
wrote in #ahfc to ,mr4 ,w4 ,ladd1 of    
,london1 he expressly emphasises by     
underscoring the word that his          
,telephone can transmit 8any sound0 that
 is sufficiently loud1 and he refers to 
the speaker and listener at the two ends
 of the line as 8the correspondents40   
,the only reply henceforth possible to  
any person who shall assert that ,reis's
 ,telephone was not expressly intended  
to transmit articulate speech is the    
good honest retort3 impudentissime      
mentiris4   ,,ii4--,reis's ,telephone1  
in the hands of ,reis and his           
contemporaries1 did transmit speech4    
,of the performance of his instruments  
,reis speaks modestly and carefully1    
nothing extenuating of his failures1    
nothing exaggerating of his successes4  
,i shall not attempt to be wiser than   
he2 nor seek to make out his instrument 

to have been either more perfect or more
 reliable than he himself knew it to be4
 ,the membrane tympanum of his          
transmitter was liable to become relaxed
 by the moisture of the breath rendering
 the instrument--as ,graham ,bell found 
fifteen years later with his membrane   
magneto-transmitters--uncertain in its  
action4 ,moreover1 in some earlier forms
 of ,reis's transmitter1 notably those  
with a vertical tympanum1 the adjustment
 of the contact-points that controlled  
the current was a matter of delicacy    
requiring experience and practice1 so   
that casual experimenters failed to     
obtain the results which ,reis himself  
obtained2#aa they obtaining only a noisy
 snarl where he obtained intelligible   
speech4 ,lastly1 the very delicacy of   
the essential parts1 the conducting     
strips of metal which lay lightly in    
contact against one another1 militated  
against a uniformity of success when    
tried with different voices1 some of    
which were too low to produce any       

effect1 others so loud as to rattle the 
delicate contact-pieces in a manner     
fatal to the attainment of the desired  
result4  ,in spite of all these         
drawbacks1 which were not inherent in   
the principle of the instrument1 there  
is plenty of evidence that ,reis's      
,telephone did transmit speech4 ,reis   
himself records this fact3  7#a47 ,in   
#ahfa1 in his memoir #8,on ,telephony'  
7see p4 #eh71 8,the consonants are for  
the most part tolerably distinctly      
reproduced1 but the vowels not yet in an
 equal degree40  7#b47 ,in his          
#8,prospectus' 7p4 #hf7 ,reis says that 
the tones of organ-pipes and of the     
piano can be reproduced as well as the  
tones of the human voice1 8according to 
my experience40  7#c47 ,the fact is     
attested by ,inspector ,wilhelm von     
,legat1 in his ,report in the           
#8,zeitschrift' 7p4 #gg71 #ahfb4 ,after 
alluding to the indistinctness of the   
vowels1 he says3 8,single words1 uttered
 as in reading1 speaking1 and the like1 

were perceptible indistinctly1          
nevertheless1 here also the inflexions  
of the voice1 the modulations of        
interrogation1 exclamation1 wonder1     
command1 etc41 attained distinct        
expression40  7#d47 ,professor ,quincke1
 of ,heidelberg1 testifies 7see p4 #aac7
 that he heard and understood words     
spoken through a ,reis ,telephone in    
#ahfd4  7#e47 ,professor ,bttger1 editor
 of the #8,polytechnisches ,notizblatt1'
 in #ahfc says 7see p4 #ij73 8,the      
experimenters could even communicate    
words to one another1 though certainly  
indeed1 only such as had often been     
heard by them40  7#f47 ,dr4 ,rudolph    
,messel1 an old pupil of ,reis1 and an  
eye-witness of his early experiments1   
has written#ab3 8,there is not a shadow 
of a doubt about ,reis having actually  
achieved imperfect articulation4 ,i     
personally recollect this very          
distinctly1 and could find you plenty   
more people who witnessed the same40    
7#g47 ,herr ,peter1 a former colleague  

of ,philipp ,reis1 whose testimony will 
be found on page #abf1 narrates how he  
doubted the powers of the instrument    
until he had verified them for himself  
by speaking into it words which could   
not possibly be premeditated4  7#h47    
,mr4 ,e4 ,horkheimer1 who aided ,reis in
 his earlier work1 though he left       
,germany when the development of the    
instrument was yet very far from        
complete1 has even given 7see p4 #aag7 a
 list of the words and expressions which
 he has heard transmitted by the earlier
 forms of the instrument4  7#i47 ,herr  
,philipp ,schmidt1 brother-in-law of    
,philipp ,reis1 and now acting-paymaster
 in the ,imperial ,german ,navy at      
,wilhelmshavn1 says3 8he succeeded      
finally in reproducing at a distance1   
words and whole sentences40 8,there     
never was any understanding between my  
brother-in-law and myself as to         
particular words and sentences3 on the  
contrary1 these were quite spontaneous40
  7#aj47 ,mr4 ,s4 ,m4 ,yeates1 of       

,dublin1 who in #ahfe constructed a     
modified ,reis ,telephone 7see p4 #abh71
 has thus described the performance of  
the instrument3 8,before disposing of   
the apparatus1 ,i showed it at the      
,november meeting 7#ahfe7 of the ,dublin
 ,philosophical ,society1 when both     
singing and the distinct articulation of
 several words were heard through it1   
and the difference between the speakers'
 voices clearly recognised40#ac  ,it is 
difficult to conceive how testimony on  
this point could be stronger4 ,from so  
many different sources it is alike      
agreed that--with the instrument        
presumably in good adjustment--,reis's  
,telephone1 in the hands of ,reis and   
his contemporaries1 did transmit        
articulate speech4   ,,iii4--,reis's    
,telephone will transmit speech4        
,reis's ,telephone consists of two      
parts3 a 8transmitter10 into which the  
speaker speaks2 and a 8receiver10 at    
which the hearer listens4 ,their various
 forms have been described in detail in 

the preceding chapter4 ,all that we are 
concerned with at this place is1 whether
 these instruments will at the present  
day do what is asserted4 ,the writer has
 tested every form of ,reis's           
transmitter1 save only some of the      
tentative historic forms shown in ,figs4
 #b-h1 #ac1 #ae1  #af1 ante1 and has    
found them perfectly competent to       
transmit speech1 provided proper        
precautions were taken3 namely1 that the
 contacts were clean and in adjustment1 
that the tympanum was tightly stretched1
 and that the speaker did not speak too 
loudly3#ad in other words1 that the     
instruments were properly used4 ,any one
 who wants not to succeed in            
transmitting speech with ,reis's        
transmitter has only to neglect these   
reasonable precautions4 ,it is not1     
therefore1 difficult to fail4 ,the      
writer has also tested both the         
better-known forms of ,reis's receiver  
7,figs4 #ba1 #bb1  #bc71 and finds that 
both are perfectly competent to receive 

speech electrically and reproduce it    
audibly1 both vowels and consonants     
being perfectly distinct and articulate1
 though never as loud as in more modern 
forms of telephone-receiver4 ,from a    
steel wire1 magnetised1 as prescribed by
 ,reis1 by surrounding it with a coil of
 wire through which the current passes1 
the writer has obtained articulation    
exceeding in perfection of definition1  
both of vowels and of consonants1 the   
articulation of any other               
telephone-receiver he has ever listened 
to4 ,perhaps it may be objected that it 
is difficult to listen to a steel wire4 
,reis met this difficulty in his own way
 by mounting his steel wire upon a small
 sounding-box to strengthen the sounds1 
and added a flat upper case against     
which the ear of the listener can be    
pressed1 and which can be removed1 or   
opened as a lid1 when a whole audience  
is to hear simultaneously the tones of  
the instrument when working in a loud   
and disagreeable manner1 as a           

transmitter of the coarser vibrations of
 a loudly sung melody4 ,the lid is not  
wanted for this latter purpose--is an   
encumbrance2 which1 nevertheless1 by its
 presence proves the more delicate      
functions of the instrument4 ,reis's    
instructions in his #8,prospectus1' p4  
#hf1 are that pressing this lid down    
firmly upon the steel core increases the
 loudness of the sounds4 ,any one who   
wants not to succeed in receiving speech
 with ,reis's receiver has1 as before1  
only to neglect reasonable precautions4 
,he has only to use an imperfect or bad 
transmitter1 or use it carelessly1 or   
put the receiver to a sufficient        
distance from his ear1 to attain this   
result4 ,there are people who have      
failed to make ,reis's receiver receive4
  ,this is not the place to discuss a   
doctrinaire objection sometimes raised1 
that it is theoretically impossible for 
,reis's instruments to work4 ,for the   
moment we are concerned with the        
practical question3 ,do they work8 ,no  

one practically experienced in          
telephones1 even if he should deny that 
,reis had any such intention1 will      
dispute that they can now be made to    
transmit speech4 ,professor ,dolbear1   
himself no mean authority on telephones1
 testifies1 as quoted above 7p4 #da71   
8that the instruments would talk1 and   
would talk well40 ,he would1 indeed1 be 
a bold man who would come forward to    
deny what can be shown any day as an    
experimental fact3 that ,reis's         
,telephone will transmit speech4  ,we   
have now shown that ,philipp ,reis was  
the undisputed inventor of an instrument
 which he called the ,telephone1 which  
instrument can now be used to transmit  
speech2 which was then used to transmit 
speech2 and which was invented on       
purpose to transmit speech4 ,so far the 
result of the examination into the facts
 of the case is conclusive enough4 ,a   
more complete case could hardly be      
desired4 ,no honest person could        
hesitate for want of proof1 either      

greater in amount or more direct to the 
point4  ,nevertheless1 ,i propose in    
another section to go a little further  
and to prove a technical point of       
highest interest2 namely1 that there is 
not in the ,telephone ,exchanges of     
,england to-day1 any single telephone to
 be found in which the fundamental      
principles of ,reis's ,telephone are not
 the essential and indispensable        
features4 ,these considerations being1  
however1 of a strictly technical nature1
 will be best considered in an          
,appendix4 ,as1 however1 we are able to 
show that those instruments which are   
now in daily use for transmitting       
speech1 embody the two fundamental      
principles upon which ,reis based the   
instrument which he called 8,das        
,telephon10 it would be dishonest to the
 memory of the deceased inventor to     
claim anything less than that he was the
 8first and true inventor0 of the       
,telephone4  ,,footnotes3  #f ,the name 
8,telephone0 had already been applied by

 ,sir ,c4 ,wheatstone 7#ahca7 to an     
acoustic arrangement for transmitting   
sounds through wooden rods to a distant 
place in a purely mechanical manner4 ,it
 is needless to observe that speech as  
well as music can be thus transmitted2  
and though ,wheatstone gave telephonic  
concerts1 this does not prove 7nor do   
telephonic concerts given through       
,reis's instrument prove7 that speech   
could not be transmitted also4 ,the name
 8,fernsprecher10 now used in ,germany  
for the ,telephone1 was only suggested  
in #ahgg by ,dr4 ,stephan1 ,postmaster  
of the ,german ,empire1 in obedience to 
the absurd fashion which has raged since
 #ahga in ,germany of rejecting words of
 classic derivation4  #g ,see           
proceedings in ,u4 ,s4 ,court 7,dowd    
suit71 ,edison's second answer1 and     
,prescott's #8,the ,speaking            
,telephone1' p4 #bah4  #h ,published    
volume of ,proceedings in the ,united   
,states ,patent ,office1 before the     
,commissioner of ,patents4 ,evidence for

 ,a4 ,g4 ,bell1 p4 #f4  #i ,proc4 ,soc4 
,telegr4 ,engin4 and ,electr4 vol4 xi4  
p4 #acd1 #ahhb4  #aj #8,electrical      
,review1' ,july #bb1 #ahhb1 p4 #di4  #aa
 ,mr4 ,e4 ,albert1 of the firm of ,j4   
,w4 ,albert and ,sohn1 of ,frankfurt1 to
 whom ,reis entrusted the manufacture of
 ,telephones for public sale1 thus      
writes3 8,the most important part was   
the membrane1 because the delicacy of   
the apparatus depended principally upon 
that part4 ,as it was not possible to   
make every membrane equally good1 so it 
came about that instruments of different
 degrees of superiority came into use1  
and various decisions were arrived at as
 to the ability of the instrument to    
perform the functions for which it was  
designed4 ,those who happened to have a 
poor instrument were able to hear but   
little2 while those who possessed a good
 instrument were astonished at its      
performances4 ,a good instrument        
reproduced the words sung into it in    
such a manner that not only the pitch   

but also the words of the song were     
perfectly understood1 even when the     
listener was unacquainted with the song 
and the words40  ,m4 ,st4 ,edm1 of      
,paris1 who contributed to #8,cosmos1'  
vol4 xxiv4 p4 #cdi1 #ahfd1 an article on
 ,reis's ,telephone1 of which he had    
seen an example in ,knig's atelier1 said
 that when the scale was sung it needed 
a trained ear to distinguish the notes  
amidst the noises of the receiver4 ,he  
must have got hold of an uncommonly bad 
transmitter with a flabby tympanum to   
have failed so completely4  #ab ,letter 
of ,dr4 ,messel to ,professor ,w4 ,f4   
,barrett quoted1 in ,professor          
,barrett's memoir1 #8,on the ,electric  
,telephone1' read ,nov4 #ai1 #ahgg1 to  
the ,dublin ,royal ,society4 ,vide      
,proc4 ,roy4 ,soc4 ,dubl4 #ahgg4  #ac   
,see ,barrett's #8,telephones ,old and  
,new' 7#ahgh71 p4 #ab4  #ad ,see ,reis's
 own remark at bottom of p4 #eg4        
,,chapter ,,iv4  ,,contemporary         
,,documents4   ,the following documents1

 drawn from the scientific literature of
 the time1 are placed in chronological  
order1 beginning with the first memoir  
published by ,philipp ,reis himself1 in 
the ,jahresbericht of the ,physical     
,society of ,frankfort1 for the year    
#ahfj-fa4 ,every care has been taken    
that the translations here given shall  
be faithful in every detail to the      
originals4 ,all notes and comments by   
the translator are distinguished by     
being enclosed in square brackets4   #a4
 ,,on ,,telephony ,,by ,,the ,,galvanic 
,,current4  ,by ,,philipp ,,reis4       
,translated from the ,annual ,report    
7,jahresbericht7 of the     ,physical   
,society of ,frankfurt-am-,main1 for    
#ahfj-ahfa4  ,the surprising results in 
the domain of ,telegraphy1 have often   
already suggested the question whether  
it may not also be possible to          
communicate the very tones of speech    
direct to a distance4 ,researches aiming
 in this direction have not1 however1 up
 to the present time1 been able to show 

any tolerably satisfactory result1      
because the vibrations of the media     
through which sound is conducted1 soon  
fall off so greatly in their intensity  
that they are no longer perceptible to  
our senses4  ,a reproduction of the     
tones at some distance by means of the  
galvanic current1 has perhaps been      
contemplated2 but at all events the     
practical solution of this problem has  
been most doubted by exactly the very   
persons who by their knowledge and      
resources should have been enabled to   
grasp the problem4 ,to one who is only  
superficially acquainted with the       
doctrines of ,physics1 the problem1 if  
indeed he becomes acquainted with it1   
appears to offer far fewer points of    
difficulty because he does not foresee  
most of them4 ,thus did ,i1 some nine   
years ago 7with a great penchant for    
what was new1 but with only too         
imperfect knowledge in ,physics71 have  
the boldness to wish to solve the       
problem mentioned2 but ,i was soon      

obliged to relinquish it1 because the   
very first inquiry convinced me firmly  
of the impossibility of the solution4   
,later1 after further studies and much  
experience1 ,i perceived that my first  
investigation had been very crude and by
 no means conclusive3 but ,i did not    
resume the question seriously then1     
because ,i did not feel myself          
sufficiently developed to overcome the  
obstacles of the path to be trodden4    
,youthful impressions are1 however1     
strong and not easily effaced4 ,i could 
not1 in spite of every protest of my    
reason1 banish from my thoughts that    
first inquiry and its occasion2 and so  
it happened that1 half without intending
 it1 in many a leisure hour the youthful
 project was taken up again1 the        
difficulties and the means of           
vanquishing them were weighed1--and yet 
not the first step towards an experiment
 taken4  ,how could a single instrument 
reproduce1 at once1 the total actions of
 all the organs operated in human       

speech8 ,this was ever the cardinal     
question4 ,at last ,i came by accident  
to put the question in another way3 ,how
 does our ear take cognizance of the    
total vibrations of all the             
simultaneously operant organs of speech8
 ,or1 to put it more generally3 ,how do 
we perceive the vibrations of several   
bodies emitting sounds simultaneously8  
,in order to answer this question1 we   
will next see what must happen in order 
that we may perceive a single tone4     
,apart from our ear1 every tone is      
nothing more than the condensation and  
rarefaction of a body repeated several  
times in a second 7at least seven to    
eight times#ae74 ,if this occurs in the 
same medium 7the air7 as that with which
 we are surrounded1 then the membrane of
 our ear will be compressed toward the  
drum-cavity by every condensation1 so   
that in the succeeding rarefaction it   
moves back in the opposite direction4   
,these vibrations occasion a lifting-up 
and a falling-down of the 8hammer0      

malleus bone upon the 8anvil0 incus bone
 with the same velocity1 or1 according  
to others1 occasion an approach and a   
recession of the atoms of the auditory  
ossicles1 and give rise1 therefore1 to  
exactly the same number of concussions  
in the fluid of the cochla1 in which the
 auditory nerve and its terminals are   
spread out4 ,the greater the            
condensation of the sound-conducting    
medium at any given moment1 the greater 
will be the amplitude of vibration of   
the membrane and of the 8hammer10 and   
the more powerful1 therefore1 the blow  
on the 8anvil0 and the concussion of the
 nerves through the intermediary action 
of the fluid4  ,the function of the     
organs of hearing1 therefore1 is to     
impart faithfully to the auditory nerve1
 every condensation and rarefaction     
occurring in the surrounding medium4    
,the function of the auditory nerve is  
to bring to our consciousness the       
vibrations of matter resulting at the   
given time1 both according to their     

number and their magnitude4 ,here1      
first1 certain combinations acquire a   
distinct name3 here1 first the          
vibrations become musical tones or      
discords 7,misstne74  ,that which is    
perceived by the auditory nerve1 is1    
therefore1 merely the action of a force 
affecting our consciousness1 and as such
 may be represented graphically1        
according to its duration and magnitude1
 by a curve4  ,illustration3 ,fig4 #bd4 
,let the line a1 b1 indicate any given  
length of time1 and the curve above the 
line a condensation 771 the curve below 
the line a rarefaction 7-71 then every  
ordinate erected at the end of an       
abscissa will give according to the     
height of it1 at a moment indicated by  
the position of the foot of the         
ordinate1 the strength of the           
condensation that is causing the        
drum-skin to vibrate4  ,our ear can     
perceive absolutely nothing more than is
 capable of being represented by similar
 curves1 and this method is completely  

sufficient to bring before our clear    
consciousness every tone and every      
combination of tones4  ,if several tones
 are produced at the same time1 then the
 medium that conducts sound is placed   
under the influence of several          
simultaneous forces2 and the two        
following laws hold good3--  ,if all the
 forces operate in the same sense1 the  
resultant motion is proportional in     
magnitude to the sum of the forces4  ,if
 the forces operate in opposite senses1 
the resultant motion is proportional in 
magnitude to the difference of the      
opposing forces4  ,let us exhibit the   
condensation-curves for three           
tones--each singly 7,table ,i47#af3     
then1 by adding together the ordinates  
corresponding to equal absciss1 we can  
determine new ordinates and develop a   
new curve which we may call the         
combination-curve or resultant curve4   
,now this gives us just exactly what our
 ear perceives from the three           
simultaneous tones4 ,it ought to cause  

us as little wonder that a musician can 
recognize the three tones1 as that 7as  
is the fact7 a person conversant with   
the science of colour1 can recognize in 
green1 blue and yellow tints4 ,the      
combination-curves of table ,i4 present1
 however1 very little difficulty1 since 
in them all the proportions of the      
component curves recur successively4 ,in
 chords consisting of more than three   
tones 7,table ,,ii471 the proportions of
 the components are no longer so easy to
 recognize in the drawing4 ,but it is   
also difficult to an accomplished       
musician1 in such chords to recognize   
the individual notes4  ,table ,,iii4    
shows us a discord4 ,why discords affect
 us so unpleasantly ,i leave            
provisionally to the contemplation of   
the gentle reader1 as ,i may perhaps    
return to this point in another memoir4 
,it follows from the preceding that3--  
7#a47 ,every tone and every combination 
of tones evokes in our ear1 if it enters
 it1 vibrations of the drum-skin1 the   

motions of which may be represented by a
 curve4#ag  7#b47 ,the motions of these 
vibrations evoke in us the perception   
7sensation7 of the tone3 and every      
change in the motion must change the    
sensation4  ,as soon1 therefore1 as it  
shall be possible at any place and in   
any prescribed manner1 to set up        
vibrations whose curves are like those  
of any given tone or combination of     
tones1 we shall receive the same        
impression as that tone or combination  
of tones would have produced upon us4#ah
  ,taking my stand on the preceding     
principles1 ,i have succeeded in        
constructing an apparatus by means of   
which ,i am in a position to reproduce  
the tones of divers instruments1 yes1   
and even to a certain degree the human  
voice4 ,it is very simple1 and can be   
clearly explained in the sequel1 by aid 
of the figure3  ,illustration3 ,fig4    
#be4  ,in a cube of wood1 r s t u v w x1
 there is a conical hole1 a1 closed at  
one side by the membrane b 7made of the 

lesser intestine of the pig71 upon the  
middle of which a little strip of       
platinum is cemented as a conductor of  
the current or electrode4 ,this is      
united with the binding-screw1 p4 ,from 
the binding-screw n there passes        
likewise a thin strip of metal over the 
middle of the membrane1 and terminates  
here in a little platinum wire which    
stands at right angles to the length and
 breadth of the strip4  ,from the       
binding-screw1 p1 a conducting-wire     
leads through the battery to a distant  
station1 ends there in a spiral of      
copper-wire1 overspun with silk1 which  
in turn passes into a return-wire that  
leads to the binding-screw1 n4  ,the    
spiral at the distant station is about  
six inches long1 consists of six layers 
of thin wire1 and receives into its     
middle as a core a knitting-needle1     
which projects about two inches at each 
side4 ,by the projecting ends of the    
wire the spiral rests upon two bridges  
of a sounding-box4 7,this whole piece   

may naturally be replaced by any        
apparatus by means of which one produces
 the well-known 8galvanic tones407  ,if 
now tones1 or combinations of tones1 are
 produced in the neighbourhood of the   
cube1 so that waves of sufficient       
strength enter the opening a1 they will 
set the membrane b in vibration4 ,at the
 first condensation the hammer-shaped   
little wire d will be pushed back4 ,at  
the succeeding rarefaction it cannot    
follow the return-vibration of the      
membrane1 and the current going through 
the little strip of platinum remains    
interrupted so long as until the        
membrane1 driven by a new condensation1 
presses the little strip 7coming from p7
 against d once more4 ,in this way each 
sound-wave effects an opening and a     
closing of the current4  ,but at every  
closing of the circuit the atoms of the 
iron needle lying in the distant spiral 
are pushed asunder from one another4    
7,mller-,pouillet1 #8,lehrbuch der      
,physik1' see p4 #cjd of vol4 ii4 #eth  

ed474 ,at the interruption of the       
current the atoms again attempt to      
regain their position of equilibrium4   
,if this happens then in consequence of 
the action and reaction of elasticity   
and traction1 they make a certain number
 of vibrations1 and yield the           
longitudinal tone#ai of the needle4 ,it 
happens thus when the interruptions and 
restorations of the current are effected
 relatively slowly4 ,but if these       
actions follow one another more rapidly 
than the oscillations due to the        
elasticity of the iron core1 then the   
atoms cannot travel their entire paths4 
,the paths travelled over become shorter
 the more rapidly the interruptions     
occur1 and in proportion to their       
frequency4 ,the iron needle emits no    
longer its longitudinal tone1 but a tone
 whose pitch corresponds to the number  
of interruptions 7in a given time74 ,but
 this is saying nothing less than that  
the needle reproduces the tone which was
 imparted to the interrupting apparatus4

  ,moreover1 the strength of this tone  
is proportional to the original tone1   
for the stronger this is1 the greater   
will be the movement of the drum-skin1  
the greater therefore the movement of   
the little hammer1 the greater finally  
the length of time during which the     
circuit remains open1 and consequently  
the greater1 up to a certain limit1 the 
movement of the atoms in the reproducing
 wire the knitting needle1 which we     
perceive as a stronger vibration1 just  
as we should have perceived the original
 wave4  ,since the length of the        
conducting wire may be extended for this
 purpose1 just as far as in direct      
telegraphy1 ,i give to my instrument the
 name 8,telephon40  ,as to the          
performance attained by the ,telephone1 
let it be remarked1 that1 with its aid1 
,i was in a position to make audible to 
the members of a numerous assembly 7the 
,physical ,society of                   
,frankfort-on-the-,main7 melodies which 
were sung 7not very loudly7 into the    

apparatus in another house 7about three 
hundred feet distant7 with closed doors4
  ,other researches show that the       
sounding-rod i4e4 the knitting needle is
 able to reproduce complete triad chords
 78,dreiklnge07 of a piano on which the 
telephone i4e4 the transmitter stands2  
and that1 finally1 it reproduces equally
 well the tones of other                
instruments--harmonica1 clarionet1 horn1
 organ-pipes1 c41 always provided that  
the tones belong to a certain range     
between ,f and f''#bj4  ,it is1 of      
course1 understood that in all          
researches it was sufficiently          
ascertained that the direct conduction  
of the sound did not come into play4    
,this point may be controlled very      
simply by arranging at times a good     
shunt-circuit directly across the spiral
 i4e4 to cut the receiving instrument   
out of circuit by providing another path
 for the currents of electricity1       
whereby naturally the operation of the  
latter momentarily ceases4  ,until now  

it has not been possible to reproduce   
the tones of human speech with a        
distinctness to satisfy everybody4 ,the 
consonants are for the most part        
tolerably distinctly reproduced1 but the
 vowels not yet in an equal degree4 ,why
 this is so ,i will endeavour to        
explain4  ,according to the researches  
of ,willis1 ,helmholtz1 and others1     
vowel sounds can be artificially        
produced by causing the vibrations of   
one body to reinforce those of another  
periodically1 somewhat after the        
following scheme3--  ,illustration3     
,fig4 #bf4  ,an elastic spring is set in
 vibration by the thrust of the tooth of
 a cog-wheel3 the first swing is the    
greatest1 and each of the others is less
 than the preceding one 7see ,fig4 #bf74
  ,after several vibrations of this sort
 7without the spring coming to rest7 let
 another thrust be given by the tooth2  
the next swing will again be a maximum  
one1 and so on4  ,the height or depth of
 the sound produced in this fashion     

depends upon the number of vibrations   
made in a given time2 but the quality of
 the note depends upon the number of    
variations of amplitude                 
7,anschwellungen7 occurring in the same 
time4  ,two vowels of equal pitch may be
 distinguished from each other somewhat 
after the manner represented by the     
curves 7#a7 7#b73 while the same tone   
devoid of any vowel quality1 is         
represented by curve 7#c74              
,illustration3 ,fig4 #bg4  ,our organs  
of speech create the vowels probably in 
the same manner by a combined action of 
the upper and lower vocal chords1 or of 
the latter and of the cavity of the     
mouth4  ,now my apparatus gives the     
number of the vibrations1 but with far  
less strength than the original ones2   
though also1 as ,i have cause to think1 
always proportional to one another up to
 a certain degree4 ,but because the     
vibrations are throughout smaller1 the  
difference between large and small      
vibrations is much more difficult to    

recognize than in the original waves1   
and the vowel is therefore more or less 
indefinite4  ,whether my views with     
respect to the curves representing      
combinations of tones are correct1 may  
perhaps be determined by aid of the new 
phonautograph described by ,duhamel4    
7,see ,vierordt's #8,physiology1' p4    
#bed47  ,there may probably remain much 
more yet to be done for the utilisation 
of the telephone in practice 7zur       
praktischen ,verwerthung des            
,telephons74 ,for physics1 however1 it  
has already sufficient interest in that 
it has opened out a new field of labour4
                                        
,philipp ,reis4    ,friedrichsdorf1 near
 ,frankfort-on-the-,main1               
in ,december #ahfa4  ,though the        
foregoing memoir1 as printed in the     
#8,jahresbericht1' of the ,physical     
,society of ,frankfort-on-the-,main1 is 
dated 8,december #ahfa10 it was         
delivered verbally on ,october #bfth    
preceding1 as the #8,proceedings' of the

 ,society show4 ,from the               
#8,jahresbericht' for the succeeding    
year we learn that three weeks after the
 delivery of this communication ,reis   
made a second communication to the      
,society on a kindred matter4 ,the entry
 is as follows 7#8,proceedings' of the  
,society1 p4 #ac73 8,on the #afth       
,november1 by the same3 ,explanation of 
a new ,theory concerning the ,perception
 of ,chords and of ,timbre              
7#8,klangfarben'71 as a ,continuation   
and ,supplement of the ,memoir on the   
,telephone40 ,so far as can now be      
learned1 the substance of this          
communication was embodied in the latter
 part of the paper 8,on ,telephony10    
when written out in ,december for       
publication4 ,on the #hth of ,january1  
#ahfb1 the formal thanks of the ,society
 were voted to ,reis for the manuscript 
which he had contributed to the         
#8,jahresbericht4'  ,it is of interest1 
moreover1 to note that the matter did   
not immediately drop4 ,professor        

,bttger1 who as one of the regular      
lecturers of the ,physical ,society1    
held fortnightly discourses on matters  
of scientific novelty1 took occasion on 
the #gth of ,december to recur to the   
subject then attracting so much         
attention4 ,the title of his discourse  
7see #8,proceedings' of the ,society1 p4
 #aa7 was 8,application of an           
,experiment relating to the             
,transmission of ,musical ,tones to any 
desired distance by means of the        
,galvanic ,current40 ,it is not quite   
certain whether ,reis was present on    
this occasion4 ,early in the spring of  
#ahfc1 appeared in ,bttger's            
#8,polytechnisches ,notizblatt' 7,no4 #f
 of that year7 an article which contains
 in condensed form ,bttger's discourse4 
,this article was copied into ,dingler's
 #8,polytechnisches ,journal' for ,may  
#ahfc4 vol4 clxviii4 p4 #ahe1 and also  
into the #8,polytechnisches             
,centralblatt' for ,july #ahfc1 vol4    
xxix4 p4 #heh4 ,an extract of ,reis's   

own paper1 condensed from the           
#8,jahresbericht' by ,dr4 ,roeber 7now  
,president of the ,physical ,society of 
,berlin71 appeared in the #8,berliner   
,berichte' 7i4 e4 the #8,fortschritte   
der ,physik'7 for #ahfa1 vol4 xvii4 pp4 
#aga-agc4 ,it is interesting to note    
that ,reis's paper was then deemed      
worthy to stand in the pages of the     
#8,fortschritte' by the side of the     
classic researches of ,thomson on       
,regelation1 and of ,maxwell on         
,magnetic ,lines of ,force4 ,the        
following is a translation of ,bttger's 
notice mentioned above4   #b4 ,,on ,,the
 ,,transmission ,,of ,,tones ,,to ,a    
,,distance ,,as ,,far ,,as ,,desired1   
,,by ,,the ,,help ,,of ,,electricity    
7,,telephony74      ,translated from the
 original notice by ,professor ,bttger1 
which appeared in ,bttger's             
#8,polytechnischen ,notizblatt1'        
#ahfc1 ,no4 #f1 p4 #ha1 in ,dingler's   
#8,polytechnisches ,journal1'     #ahfc1
 vol4 clxviii4 p4 #ahe1 and in the      

#8,polytechnisches     ,centralblatt1'  
#ahfc1 t4 xxix4 p4 #heh4  ,two decades  
ago we had not yet gone beyond the first
 attempts to give signals at a great    
distance by the aid of electricity4     
,since then telegraphy has attained such
 a completeness1 and the telegraph wire 
has reached such a universal extension1 
that there seems little left for even   
the boldest wish to desire4  ,now there 
crops up a first serious research to    
reproduce tones at any desired distance 
by the aid of electricity4 ,this first  
experiment which has been crowned with  
some success1 has been made by the      
teacher of ,natural ,science at         
,friedrichsdorf1 not far from           
,frankfort-on-the-,main1 ,herr ,ph4     
,reis1 and has been repeated in the     
,auditorium of the ,physical ,society in
 ,frankfort1 before numerous assembled  
members on the #bfth of ,october1 #ahfa4
 ,he caused melodies to be sung not very
 loudly into one part of his apparatus1 
which was placed in a building 7the     

,brger-,hospital71 about #cjj feet      
distant1 with closed windows and doors4 
,these same melodies were audible to the
 members in the meeting-hall by means of
 the second part of the apparatus4      
,these wonderful results were attained  
with the following simple pieces of     
apparatus4 ,a little light box1 a sort  
of hollow cube of wood1 has a large     
opening at its front side1 and a small  
one at the back on the opposite side4   
,the latter is closed with a very fine  
membrane 7of pig's smaller-intestine7   
which is strained stiff4 ,a narrow      
springy strip of platinum foil1 fixed at
 its outer part to the wood1 touches the
 membrane at its middle2 a second       
platinum strip is fastened by one of its
 ends to the wood at another spot1 and  
bears at its other end a fine horizontal
 spike1 which touches the other little  
platinum strip where it lies upon the   
membrane4  ,as is known1 tones arise    
from rarefactions and condensations of  
the air following quickly after one     

another4 ,if these motions of the air1  
known as waves1 strike upon the thin    
membrane1 they press it against the     
little plate of platinum with which it  
is in contact1 and immediately let it   
vibrate back again into the hollow cube 
7or so-called artificial ear73 they act 
so that the membrane now takes a form   
hollowed toward the cube1 now bulged    
toward the outside4 ,the little plate of
 platinum touching it thereby acquires a
 vibrating motion1 so that it now is    
pressed against the spike of the second 
platinum plate1 now leaves the same4    
,if now one little plate of platinum be 
united by a wire with one pole of a     
voltaic battery1 and the electricity be 
led1 by a wire fastened to the other    
pole of the battery1 to any desired     
distance2 there carried through a       
spiral1 about six inches long1 made of a
 six-fold winding of very thin covered  
copper wire2 thence led back to the     
second platinum strip on the wooden cube
 through a second insulated wire2 then  

at every vibration of the membrane an   
interruption in the current of          
electricity takes place because the     
platinum point no longer touches the    
other little strip of platinum4 ,through
 the hollow of the wire-spiral there is 
stuck a thin iron wire 7a strong        
knitting-needle71 which is ten inches   
long1 and which rests upon two bridges  
of a sounding-board by its ends which   
project on both sides about two inches  
out of the spiral4  ,it is known#ba that
 if an electric current be led through a
 spiral which surrounds an iron rod in  
the manner described1 at every          
interruption of the same a tone is      
audible arising from the vibration of   
the rod4 ,if the closings and           
interruptions of the circuit follow one 
another relatively slowly1 then there is
 produced by the changes of position of 
the molecules of the rod1 evoked by the 
electricity1 a tone1--the so-called     
longitudinal tone of the rod1--which is 
dependent upon the length and stoutness 

of the rod4 ,but if the closings and    
interruptions of the electric current in
 the spiral follow one another more     
rapidly than the vibrations of the      
smallest particles of the iron rod1#bb  
which vibrations are determined by its  
elasticity1 then these particles cannot 
complete their paths1 receive new       
impacts1 their vibrations become        
smaller1 but quicker1 and follow one    
another as frequently as the            
interruptions4 ,the iron rod then no    
longer gives its longitudinal tone1 but 
a tone1 which is higher according as the
 interruptions are more frequent in the 
given time1 or lower1 as they are less  
frequent4 ,it is known that the height  
and depth of tones depends only on the  
number of air-waves which follow one    
another in a second4 ,we have seen above
 that by this is determined the number  
of interruptions of the electric current
 of our apparatus by means of the       
membrane and the platinum strip4 ,the   
iron wire must therefore give out the   

tone in the same height or depth as that
 which struck the membrane4 ,now since a
 very far leading of the electricity    
makes it suffer scarcely any weakening  
in proper apparatus1 it is intelligible 
that one can make the tone which acts on
 the membrane at one place audible1 by  
means of the iron rod1 at any desired   
distance4  ,that the tone is made       
audible at a distance by the electric   
agitations1 and not by direct conduction
 of the sound-waves through the wires is
 proved in the most evident way of all1 
because one instantly hears no more the 
tone through the spiral when a good     
short circuit is made1 as1 for example1 
by laying upon the two wires which      
conduct the electricity a strip of sheet
 metal right in front of the spiral4    
,the reproduced tones are1 of course1   
somewhat weaker than the original ones1 
but the number of vibrations is similar4
 ,if thus the reproduction of tones in  
exactly similar height and depth is     
easily attained1 it is however difficult

 for our ear1 amidst the always smaller 
vibrations1 to which the diminished     
strength of the tone is due1 to evaluate
 exactly the magnitude of the           
vibrations4 ,but the character of the   
tone depends upon the number of         
variations of amplitude                 
7,anschwellungen71 that is to say1      
depends upon whether1 for example1 in   
the tones which have similar pitch and  
therefore a similar number of waves per 
second1 the fourth1 sixth1 eighth1      
tenth1 or sixteenth wave is stronger    
than the others4 ,for physicists have   
shown that an elastic spring is set in  
vibration by the thrust of the teeth of 
a cog-wheel2 the first vibration is the 
greatest1 all those that follow being   
less4 ,if there comes1 before the spring
 comes to rest1 a fresh thrust from a   
cog1 then the next vibration is again   
equal to the greatest first vibration   
without the spring making any more      
vibrations on that account2 and by this 
means vowel-tones may be artificially   

produced4  ,one may also be yet far     
removed from being able to carry on a   
conversation with a friend dwelling a   
hundred miles distant1 and recognise his
 voice1 as if he sat near us2 but it can
 no longer be maintained that this is   
impossible4 ,indeed the probability that
 this will be attained#bc is already    
become as great as the probability of   
the reproduction of natural colours in  
photography has become through the      
notable researches of ,niepce4          
99       99       99       99       99  
,the second public exhibition which     
,reis made of the telephone was1 like   
the first1 in ,frankfort-on-the-,main1  
but this time before a ,society known as
 the ,freies ,deutsches ,hochstift1 or  
,free ,german ,institute1 a kind of     
,athenum ,club for the city of          
,frankfort1 now for many years          
established in the well-known house     
where the poet ,goethe was born1 in the 
,grosse ,hirschgraben4 ,in #ahfb1       
however1 the ,free ,german ,institute   

held its meetings in another building   
known as the ,saalbau4 ,and on ,may the 
#aath of that year ,philipp ,reis       
lectured upon and exhibited the         
,telephone4 ,a journal which appeared   
then1 and still appears1 in ,frankfort1 
with the title of #8,didaskalia1'       
devoted to light literary and artistic  
news1 popular science1 and general      
intelligence of an informing character1 
ordinarily inserted notices of the chief
 meetings of the ,hochstift4 ,on this   
occasion a preliminary paragraph was    
inserted in the following terms3--   #c4
 ,,telephony1 i4e4                      
,,sound-,,transmission4  ,,translation  
,,from #8,,didaskalia1' ,,may #h,,th1   
#ahfb4  ,the excellent physicist1 ,mr4  
,phil4 ,reis1 of ,friedrichsdorf1 calls 
by this name his surprising invention   
for using the telegraph line to transmit
 really audible tones4 ,our readers will
 perhaps remember having heard some time
 since of this invention1 the first     
trials with which ,mr4 ,reis performed  

here in the ,physical ,society4 ,since  
then the invention has been constantly  
developed1 and will1 no doubt1 become of
 great importance4  ,the lecture which  
followed this announcement was duly     
given on the #aath of ,may4 ,in the     
,saalbau there is a suite of four rooms4
 ,the ,lecture to the assembled members 
of the ,hochstift was delivered in the  
,auditorium1 at one end of the suite3   
the wires were passed through the two   
intervening rooms to the fourth chamber1
 where the transmitter was placed1 the  
doors being closed4 ,the battery and    
wires were borrowed from the ,physical  
,society for this occasion1 permission  
for their use having been granted on    
,may #bnd1 as appears in a formal entry 
in the minute-book4 ,the following      
notice of ,reis's discourse1 believed to
 have been written by ,dr4 ,volger1     
,founder and first ,president of the    
,hochstift1 appeared in #8,didaskalia'  
for ,may #adth4   #d4 ,,translation     
,,from #8,,didaskalia1' #ab,,th ,,may1  

#ahfb4  ,yesterday's meeting of the     
,free ,german ,institute was a very     
numerously attended one from the fact   
that the subject in the order of        
business1 8,telephony by ,transmission  
of the ,galvanic ,current10 as explained
 by the inventor himself1 ,mr4 ,phil4   
,reis1 excites so great an interest that
 it rightly deserves the most general   
attention4  ,in a lecture exceedingly   
interesting1 universally understood1    
clear1 and concise1 ,mr4 ,reis gave a   
historical outline of the origin and    
development of his idea of the practical
 possibility of the transmission of     
tones in a galvanic way4  ,his first    
attempts were mostly unsuccessful in    
solving the cardinal question propounded
 by him4 8,how is it possible that a    
single instrument can reproduce at once 
the total action of all the organs      
operated in human speech80 ,until       
finally it occurred to him to seek the  
solution of the problem in the question1
 8,how does our ear take cognisance of  

the total vibrations of all the organs  
of speech acting at once80 or 8,how do  
we perceive the vibrations of several   
bodies sounding at once80  ,in order to 
answer this question the lecturer went  
more closely into the anatomy of the ear
 and into the formation of tones in     
general4 ,after this was determined1 he 
took up again his experiments in        
reference to the transmission of tones  
by means of galvanism4  ,afterwards ,mr4
 ,reis constructed considerably enlarged
 the parts of the ear necessary for     
hearing1 by which it was finally        
possible for him to transmit the tones  
brought to the mechanically-imitated    
ear4  ,the experiments by him some      
months ago in the ,physical ,society1   
were1 to the astonishment of all1       
exceedingly plain and clear1 whereas the
 experiment following the lecture of    
yesterday was less successful4 ,this was
 due partly to the poor conductivity of 
the wires1 partly to the locality4      
,although much is still left to be done 

for the practical utilisation           
7,verwerthung7 of the telephone1 yet a  
new and interesting field of labour is  
hereby opened to physics4  ,no more     
complete report than the foregoing is to
 be found1 and it is believed that the  
discourse1 which like all those given by
 ,reis was delivered extempore1 was     
never committed to writing4 ,its        
resemblance to the discourse of the     
preceding autumn before the ,physical   
,society is great2 and indeed it may be 
said that all ,reis's discourses upon   
the telephone were practically identical
 in their contents4 ,a few months after 
this lecture1 ,reis presented a pair of 
instruments1 transmitter and receiver1  
to the ,hochstift4 ,these instruments   
were not the same as those used by ,reis
 at his lecture1 but were of the        
8improved0 type1 whilst those used by   
,reis at his lecture to the ,hochstift1 
were1 so far as respects the transmitter
 at least1 more like the form described 
by ,w4 von ,legat1 and figured in ,plate

 ,,ii41 ,fig4 ,a2#bd and according to   
,mr4 ,horkheimer1 who helped ,reis on   
this occasion1 the transmitter was      
provided with a conical mouthpiece of   
wood4 ,the transmitter presented later  
by ,reis is of the 8square-box0 form    
7,fig4 #ag71 and is stamped1 8#ahfc1    
,philipp ,reis1 #b10 and the receiver is
 of the 8knitting-needle0 form 7,fig4   
#bc74 ,these instruments are carefully  
preserved by the ,hochstift in the      
8,goethehaus10 amongst their archives   
8in everlasting remembrance0 of the     
inventor4 ,a few months later1 in #ahfc1
 the ,emperor of ,austria and the late  
king ,max of ,bavaria were residing at  
,frankfurt and visited the              
8,goethehaus20 and on this occasion     
,reis's instruments were shown to these 
distinguished visitors by the ,founder  
and ,president of the ,hochstift1 ,dr4  
,volger4  ,in honour of his brilliant   
invention ,reis was1 shortly after his  
lecture1 elected an honorary member of  
the ,freies ,deutsches ,hochstift4      

99       99       99       99       99  
,the next document in order is a ,report
 by ,wilhelm von ,legat1 communicated to
 the ,austro-,german ,telegraph ,union  
7,verein7 in #ahfb1 and printed in the  
#8,journal' of that ,society4 ,it was   
reprinted verbatim in ,dingler's        
#8,polytechnisches ,journal1' for #ahfc1
 vol4 clxix4 p4 #bi4 ,this ,report is of
 great importance4 ,it is quoted by     
,graham ,bell1 in his earliest account  
of his telephone4 ,it was this ,report1 
moreover1 which in #ahge or #ahgf1 in a 
translated manuscript form1 was put into
 ,mr4 ,edison's hands by the then       
,president of the ,western ,union       
,telegraph ,company1 and which formed   
the starting-point of ,edison's         
subsequent work4   #e4 ,,on ,,the       
,,reproduction ,,of ,,tones ,,in ,,the  
,,electro-,,galvanic ,,way4  ,by ,v4    
,,legat1 ,inspector of the ,royal       
,prussian ,telegraphs in ,cassel4       
,translated from the ,journal of the    
,austro-,german ,telegraph     ,society 

7edited by ,dr4 ,brix71 vol4 ix4 p4     
#abe1 #ahfb4     7,zeitschrift des      
deutschsterreichischen                  
,telegraphen-,vereins1     #ahfb47  ,it 
might not be uninteresting to make known
 to wider circles the following ideas   
concerning the reproduction of tones in 
an electro-galvanic way1 which have     
recently been put forward by ,herr      
,philipp ,reiss sic of ,friedrichsdorf1 
before the ,physical ,society1 and      
before the meetings of the ,free ,german
 ,institute 7,freies ,deutsches         
,hochstift7 in ,frankfort-on-the-,main2 
also to state what has hitherto been    
attained in the realisation of this     
project1 in order that building upon the
 collected experiences and the efficacy 
of the galvanic current1 what has       
already been made serviceable to the    
human intellect for the advancement of  
its correspondence1 may in this respect 
also be turned to profit4  ,in what is  
here announced we are concerned not with
 the action of the galvanic current in  

moving telegraphic apparatus of whatever
 construction for producing visible     
signals1 but with its application for   
the production of audible signals--of   
tones6  ,the air-waves1 which by their  
action within our ears awaken in us the 
sensation of sound1 by first of all     
setting the drum-skin into a vibrating  
motion1 are thence1 as is known1        
conveyed to the inner part of the ear   
and to the auditory nerves lying there  
by a lever apparatus of the most        
marvellous fineness1--the auditory      
ossicles 7including 8,hammer10 8,anvil10
 and 8,stirrup074 ,the experiment for   
the reproduction of tones is based upon 
the following3 viz4 to employ an        
artificial imitation of this            
lever-apparatus and to set it in motion 
by the vibrations of a membrane like the
 drum-skin in the ear1 and thus to open 
and close a galvanic circuit which is   
united by a metallic conductor with a   
distant station4  ,before the           
description of the necessary apparatus  

is followed out1 it might be necessary1 
however1 to go back to the point how our
 ear perceives the vibrations of a given
 tone1 and the total vibrations of all  
the tones simultaneously acting upon it2
 because by this means will be          
determined the various requisite        
conditions which must be fulfilled by   
the transmitting and receiving apparatus
 for the solution of the problem that   
has been set4  ,let us consider first   
the processes which take place in order 
that a single tone should be perceived  
by the human ear2 so shall we find that 
each tone is the result of a            
condensation and rarefaction several    
times repeated in a certain period of   
time4 ,if this process is going on in   
the same medium 7the air7 in which our  
ear is situated1 the membrane will at   
every condensation be forced toward the 
hollow of the drum1 and at every        
rarefaction will move itself in the     
opposite direction4  ,these vibrations  
necessitate a similar motion of the     

auditory ossicles1 and thereby a        
transference to the auditory nerves is  
effected4  ,the greater the condensation
 of a sound-conducting medium at any    
given moment1 the greater also will be  
the amplitude of vibration of the       
membrane and of the auditory ossicles   
and of their action2 and in the converse
 case the action will be proportionally 
less4 ,it is1 therefore1 the function of
 the organs of hearing to communicate   
with fidelity to the auditory nerves    
every condensation and rarefaction      
occurring in the surrounding medium2    
whilst it remains to be the function of 
the auditory nerves to bring to our     
consciousness the number as well as the 
magnitude of the vibrations ensuing in a
 given time4  ,here in our consciousness
 a definite name is given to a certain  
composition1 and here the vibrations    
brought to the consciousness become     
8tones40  ,that which is perceived by   
our auditory nerves is consequently the 
effect upon our consciousness of a force

 which1 according to its duration and   
magnitude1 may for the sake of better   
comprehension1 be exhibited graphically4
  ,illustration  ,let1 for example1 the 
length of the line a b be any definite  
duration of time1 and let the curves    
above this line denote the condensations
 771 and the curves below this line the 
rarefactions 7-72 then every ordinate   
erected at the extremity of an abscissa 
gives us the strength of the            
condensation in consequence of which the
 drum-skin vibrates1 at the moment      
indicated by the position of the foot of
 the ordinate4  ,anything more than that
 which is exhibited in this way or by   
similar curves our ear cannot in the    
least perceive1 and this is sufficient  
to bring to our consciousness each      
single tone and each given combination  
of tones4 ,for1 if several tones are    
produced at the same time1 the          
sound-conducting medium is put under the
 influence of several simultaneously    
acting forces which are subject to the  

laws of mechanics4  ,if all the forces  
operate in the same sense1 then the     
magnitude of the motion is proportional 
to the sum of the forces4 ,if the forces
 act in opposite directions1 the        
magnitude of the motion is proportional 
to the difference between the opposing  
forces4  ,consequently it is possible   
out of the condensation-curves of       
several simultaneously-occurring tones  
to compound1 by the foregoing           
principles1 a condensation-curve which  
exactly expresses that which our ear    
experiences on the reception of these   
simultaneously-acting tones4 ,the       
objection ordinarily made to this1 that 
a musician1 or even any one1 is able to 
hear separately the single tones of     
which this combined curve is built and  
constructed1 cannot be admitted as a    
proof to the contrary2 for one expert in
 the science of colour will1 for        
example1 in the same way discern in     
green a mixture of yellow and blue in   
their various shades3 and the one       

phenomenon equally with the other may be
 referred back to this2 that1 to the    
person concerned1 the factors which make
 up the product of that which reaches   
his consciousness are well known4       
,according to that which has been       
already explained1 it is easy to        
construct the condensation-curves of    
various tones1 chords1 c41 and for the  
sake of clearness some examples         
follow3--  ,fig4 #a1 ,plate ,i41#be     
shows a combination curve of three      
tones1 in which all the proportions of  
the components recur successively4      
,fig4 #b shows such a curve of more than
 three tones1 in which the proportions  
in the drawing can no longer so         
evidently be given2 yet the practised   
musician would here recognise them1 even
 although in practice it might be       
difficult for him to single out1 in such
 chords1 the separate tones4  ,this     
method of exhibiting the action of tones
 upon the human ear offers the advantage
 of a very clear perception of the      

process2 and that which is exhibited    
7,fig4 #c7 shows also why a discord must
 affect our ear unpleasantly4  ,this    
apparent digression from the aim set    
forth was necessary in order to indicate
 that as soon as it is possible for us  
to create anywhere1 and in any manner   
whatever1 vibrations whose curves and   
magnitudes are similar to the vibrations
 of any given tone1 or of any given     
combination of tones1 we shall have the 
same impression as this original tone or
 this original combination of tones     
would have produced upon us4  ,the      
apparatus hereafter described offers the
 possibility of creating these          
vibrations in every fashion that may be 
desired1 and the employment of          
electro-galvanism gives us the          
possibility of calling into life1 at any
 given distance1 vibrations similar to  
the vibrations that have been produced1 
and in this way to reproduce at any     
place the tones that have been          
originated at another place4  ,in ,fig4 

#d1 ,plate ,,ii41#bf herewith presented1
 ,a is the transmitter 7,tonabgeber71   
and ,b the receiver 7,tonempfnger71     
which two instruments are set up at     
different stations4 ,i make1 however1   
the preliminary remark that the manner  
of joining the instruments for          
interchangeable use backward and forward
 is here omitted for the sake of        
clearness1 and the more so because the  
whole is not here propounded as a final 
fact1 but in order to bring that which  
has been hitherto accomplished to the   
knowledge of a wider circle4 ,the       
possibility of the working of the       
apparatus to a greater distance than    
that which at present limits in practice
 the direct working of the galvanic     
current may also be left out of         
consideration1 since these points may be
 easily rendered possible by mechanical 
precautions1 and do not affect the      
essential part of the phenomena now     
described4  ,let us next turn to the    
transmitter1 ,fig4 ,a4 ,it is put into  

communication on one side with the      
metallic conductor leading to the       
neighbouring station1 and by means of   
this with the receiver1 ,fig4 ,b2 on the
 other side it is connected1 by means of
 the electro-motive power1 ,c1 with the 
earth or a metallic return-conductor4   
,the transmitter1 ,fig4 ,a1 consists of 
a conical tube1 a b1 of about #ae       
centimetres length1 #aj centimetres in  
the front1 and #d centimetres in the    
back aperture4  7,in the practical      
investigations it has been established  
that the choice of material for this    
tube is without influence on the use of 
the apparatus1 and moreover a greater   
length of the same for the certainty of 
action of the apparatus is without      
effect4 ,a greater width of the cylinder
 spoils the usefulness of the apparatus2
 and it is recommended that the interior
 surface be as smooth as possible47     
,the narrow hinder aperture of the      
cylinder is closed by a membrane1 o1 of 
collodion1 and on the middle of the     

circular surface formed by this membrane
 rests one end1 c1 of the lever1 c d1   
the fulcrum 7point of support71 c1 of   
which1 supported on a bearing1 remains  
joined to the metallic conductor4  ,the 
choice of the length of the two arms of 
the lever1 c e and e d1 is determined by
 the laws of force of levers4 ,it is    
recommended that the arm1 c e1 be       
constructed longer than the arm e d1 in 
order to bring the smallest movement at 
c into action at d with the greatest    
possible force2 but1 on the other hand1 
it is desirable to make the lever itself
 as light as possible1 in order that it 
may follow the motions of the membrane4 
,an uncertain following of the lever1 c 
d1 produces impure tones at the         
receiving station4 ,in the condition of 
rest the contact1 d g1 is closed1 and a 
delicate spring1 n1 holds the lever     
firmly in this position of rest4  ,the  
second part of this apparatus1 the      
pillar1 f1 consists of a metallic       
support1 which is united with one pole  

of the battery1 ,c1 while the second    
pole of the battery is carried to the   
metallic conductor of the other station4
  ,upon the support1 f1 there is a      
spring1 g1 with a contact1 which        
corresponds to the contact at d of the  
lever c d1 and whose position is        
regulated by a screw1 h4  ,in order not 
to weaken the action of the apparatus by
 the communication of the air-waves     
which are produced in using the         
apparatus1 against the back of the      
membrane1 it is recommended1 in using   
the apparatus1 to place over the tube1 a
 b1 at right angles to its longitudinal 
axis1 a screen of about #ej centimetres 
diameter1 which fixes tight upon the    
outer surface of the tube4  ,the        
receiver1 ,fig4 ,b1 consists of an      
electro-magnet1 m m1 which reposes upon 
a sounding-box1 u w1 and whose wire     
coils are respectively connected with   
the metallic conductor and with the     
earth or metallic return-conductor4     
,opposite the electro-magnet1 m m1      

stands an armature1 which is connected  
with a lever1 i1 which is long as       
possible1 but light and broad4  ,the    
lever1 i1 is fastened1 pendulum-wise1 to
 the support1 k1 and its movements are  
regulated by the screw1 l1 and the      
spring1 p4  ,in order to improve the    
action of the apparatus1 this receiver  
can be placed in one focus of an        
elliptically arched cavity of           
corresponding size1 in which case1 then1
 the ear of him who is listening to the 
reproduced tones may be placed at the   
second focus of this cavity4  ,the      
action of the two apparatuses here      
described1 is the following3--  ,in a   
condition of rest the galvanic circuit  
is closed4  ,in the apparatus1 ,fig4 ,a1
 by speaking 7singing1 or leading into  
it the tones of an instrument7 into the 
tube a b1 in consequence of the         
condensation and rarefaction of the air 
present in this tube1 there will be     
evoked a motion of the membrane closing 
the tube at its narrow end1             

corresponding to this condensation or   
rarefaction4 ,the lever1 c d1 follows   
the motion of the membrane1 and opens   
and closes the galvanic circuit at d g1 
so that by each condensation of the air 
in the tube an opening1 and at each     
rarefaction a closing of the galvanic   
circuit ensues4  ,in consequence of this
 process1 the electro-magnet of ,fig4 ,b
 7the receiver7 will be demagnetised and
 magnetised correspondingly with the    
condensations and rarefactions of the   
mass of air in the tube ,a1 a b the     
mouth-piece of the transmitter1 and the 
armature belonging to the magnet will be
 set into vibrations similar to those of
 the membrane in the transmitting       
apparatus4 ,the plank1 i1 connected with
 the armature1 conveys these similar    
vibrations to the air surrounding the   
apparatus1 ,fig4 ,b1 which finally      
transmits to the ear of the listener the
 tones thus produced4  ,we are not1     
therefore1 dealing here with a          
propagation of sound through the        

electric current1 but only with a       
transference to another place of the    
tones that have been produced1 by a like
 cause being brought into play at this  
second place1 and a like effect         
produced4  ,here1 however1 it must not  
be overlooked that the preceding        
apparatus reproduces1 indeed1 the       
original vibrations in equal number1 but
 that equal strength in the reproduced  
vibrations has not yet been attained1   
and the production of these is reserved 
for a completion of the apparatus4  ,one
 consequence of this temporary          
incompleteness of the apparatus1 is that
 the slighter differences of the        
original vibrations are more difficult  
to discern3 that is to say1 the vowel   
appears more or less indistinct1 the    
more so since each tone is dependent1   
not only on the number of vibrations of 
the medium1 but also on the condensation
 or rarefaction of the same4  ,by this  
it is also explained1 that1 in the      
practical investigations heretofore     

carried on1 chords1 melodies1 etc41 were
 transmitted with marvellous fidelity2  
while single words uttered as in        
reading1 speaking1 and the like1 were   
perceptible more indistinctly4          
,nevertheless1 here also the inflexions 
of the voice1 the modulations of        
interrogation1 exclamation1 wonder1     
command1 c41 attained distinct          
expression4  ,there remains no doubt1   
that before expecting a practical       
utilisation with serviceable results    
7praktische ,verwerthung mit ,nutzen71  
that which has been here spoken of will 
require still considerable improvement1 
and in particular mechanical science    
must complete the apparatus to be used2 
yet ,i am convinced by repeated         
practical experiments that the          
prosecution of the subject here         
explained is of the highest theoretical 
interest1 and that our intelligent      
century will not miss the practical     
utilisation 7,verwerthung7 of it4       
99       99       99       99       99  

,this article was also reprinted        
verbatim in ,dingler's ,polytechnisches 
,journal1 vol4 clxix4 p4 #bi1 #ahfc4    
99       99       99       99       99  
,a peculiar interest is attached to the 
foregoing article1 partly on account of 
the unique nature of the instruments    
therein described1 partly because of the
 mystery attaching to the author of the 
article4 ,wilhelm von ,legat was        
,inspector of the ,royal ,prussian      
,telegraphs at ,cassel4 ,how or when he 
became acquainted with ,philipp ,reis is
 not known--possibly whilst the latter  
was performing his year of military     
service at ,cassel in #ahee4 ,none of   
,reis's intimate friends or colleagues  
now surviving can give any information  
as to the nature of von ,legat's        
relations with ,reis1 as not even his   
name is known to them1 save from this   
,report4 ,yet he was for one year only  
7#ahfb71 the year in which this ,report 
was made1 a member of the ,physical     
,society of ,frankfort-on-the-,main4 ,it

 is possible that he may have been      
present at ,reis's discourse in the     
preceding ,october4 ,it is probable that
 he was present at ,reis's subsequent   
discourse in ,may1 #ahfb1 to the ,freies
 ,deutsches ,hochstift4 ,dr4 ,brix1 then
 editor of the #8,journal of the        
,telegraph ,union1' informs me that     
,inspector von ,legat based his article 
upon information derived direct from    
,reis1 whom he knew1 and that the       
article was submitted to ,reis before   
being committed to the #8,journal4' ,the
 particular form of transmitter         
described in von ,legat's ,report 7see  
also p4 #be1 ante7 has also some        
important points in common with that    
believed to have been used by ,reis at  
the ,hochstift4 ,neither of the specific
 forms described by ,inspector von      
,legat are now known to be extant4      
,inquiries made in ,frankfort and in    
,cassel have failed to find any trace of
 them4 ,neither at the local            
,naturalists' ,society1 nor anywhere    

else in ,cassel1 did von ,legat describe
 the invention4 ,he met with a tragic   
end during the ,bavarian ,war in #ahff1 
in the battle near ,aschaffenburg1      
having1 according to some1 been shot1   
or1 according to others1 fallen from his
 horse4         99       99       99    
99       99  ,the next extract is from  
an article entitled #8,telephonie1'     
which appeared in a journal of science  
published at ,leipzig1 under the title  
#8,aus der ,natur4' ,this article is    
essentially a paraphrase of ,reis's     
memoir read to the ,physical ,society in
 the preceding ,december 7see p4 #ej71  
and contains the same illustrations1    
including a cut of the transmitter      
identical with ,fig4 #i1 p4 #bj4   #f4  
,,aus ,,der ,,natur4 7,vol4 xxi4 #ahfb4 
,july-,october4 pp4 #dgj-dgd47  8,until 
now1 however1 it was not possible to    
reproduce human speech with a           
distinctness sufficient for every       
person4 ,the consonants are mostly      
tolerably distinctly reproduced1 but the

 vowels not in an equal degree40        
99       99       99       99       99  
,about this time there arose a          
,correspondence in the #8,deutsche      
,industrie ,zeitung' 7#8,german ,journal
 of ,industry'7 concerning the          
telephone4 ,in ,no4 xvi4 p4 #ahd        
7#ahfc71 a correspondent who signs      
himself 8,k0 asks whether the account of
 the telephone is true8 ,in ,no4 xviii4 
p4 #bjh1 there is given a brief answer2 
and ,no4 xxii4 contains1 on p4 #bci1 an 
extract from ,legat's ,report1 on       
,reis's ,telephone 7see p4 #gj of this  
work71 together with an editorial remark
 to the effect that he had received a   
letter from ,herr ,j4 ,f4 ,quilling1 of 
,frankfort-on-the-,main1 who gives the  
information that in the transmission of 
singing in the telephone1 the singer    
could be recognized by his voice4   #g4 
,,extract ,,from ,,the ,,annual ,,report
 ,,of ,,the ,,physical ,,society ,,of   
,,frankfort-,,on-,,the-,,main 7#ahfc74  
4442 8and on the #dth of ,july1 #ahfc1  

by ,mr4 ,philipp ,reis1 teacher1 of     
,friedrichsdorf1 ,on the ,transmission  
of ,tones to any desired ,distance1 by  
the help of ,electricity1 with the      
production of an ,improved ,telephone1  
and ,exhibition of ,experiments         
therewith40  ,this was ,reis's second   
occasion of bringing his ,telephone     
before the ,physical ,society4 ,the     
instrument had now-assumed the          
8square-box0 pattern described at p4 #bg
 of this work4   #h4 ,,letter ,,of      
,,philipp ,,reis4  ,in ,july #ahfc1 ,mr4
 ,w4 ,ladd1 the well-known              
instrument-maker of ,london1 bought one 
of ,reis's ,telephones of ,messrs4 ,j4  
,w4 ,albert and ,son of ,frankfort4     
,philipp ,reis wrote to ,mr4 ,ladd the  
following letter of instructions1 having
 heard that ,mr4 ,ladd proposed to      
exhibit the instrument at the           
approaching meeting of the ,british     
,association4 ,the autograph letter1    
written in ,english1 is still preserved1
 and has been presented by ,mr4 ,ladd to

 the ,society of ,telegraph ,engineers  
and of ,electricians of ,london4        
8,institut ,garnier1                    
8,friedrichsdorf4     8,dear ,sir6      
8,i am very sorry not to have been in   
,francfort when you were     there at   
,mr4 ,albert's1 by whom ,i have been    
informed that     you have purchased one
 of my newly-invented instruments       
7,telephons74 ,though ,i will do all in 
my power to give you the     most ample 
explanations on the subject1 ,i am sure 
that personal     communication would   
have been preferable2 specially as ,i   
was     told1 that you will show the    
apparatus at your next sientifical      
meeting and thus introduce the apparatus
 in your country4      8,tunes#bg and   
sounds of any kind are only brought to  
our     conception by the condensations 
and rarefactions of air or     any other
 medium in which we may find ourselves4 
,by every     condensation the tympanum 
of our ear is pressed inwards1 by       
every rarefaction it is pressed outward 

and thus the tympanum     performs      
oscillations like a pendulum4 ,the      
smaller or greater     number of the    
oscillations made in a second gives us  
by help of     the small bones in our   
ear and the auditory nerve the idea of a
     higher or lower tune4      8,it was
 no hard labour1 either to imagine that 
any other     membrane besides that of  
our ear1 could be brought to make       
similar oscillations1 if spanned in a   
proper manner and if     taken in good  
proportions1 or to make use of these    
oscillations     for the interruption of
 a galvanic current4      8,however     
these were the principles wich 7sic7    
guided me     in my invention4 ,they    
were sufficient to induce me to try     
the reproduction of tunes i4e41         
tones--see footnote4--,s4     ,p4 ,t4 at
 any distance4 ,it would be long to     
relate all the     fruitless attempts1  
,i made1 until ,i found out the         
proportions     of the instrument and   
the necessary tension of the membrane4  

,the apparatus you have bought1 is now1 
what may be found most     simple1 and  
works without failling when arranged    
carefully in     the following manner4  
8,the apparatus consists of two         
separated parts2 one for the     singing
 station ,a1 and the other for the      
hearing station ,b4#bh                  
,illustration3 ,fig #bh4      8,the     
apparatus ,a1 a square box of wood1 the 
cover of which     shows the membrane   
7c7 on the outside1 under glass4 ,in the
     middle of the latter is fixed a    
small platina plate to which     a      
flattened copper wire is soldered on    
purpose to conduct the     galvanic     
current4 ,within the cercle you will    
further remark     two screws4 ,one of  
them is terminated by a little pit in   
which     you put a little drop of      
quiksilver2 the other is pointed4 ,the  
angle1 which you find lying on the      
membrane1 is to be placed     according 
to the letters1 with the little whole   
hole 7a7     on the point 7a7 the little

 platina foot 7b7 into the              
quicksilver screw1 the other platina    
foot will then come on the     platina  
plate in the middle of the membrane4    
8,the galvanic current coming from the  
battery 7which ,i compose     generally 
of three or four good elements7 is      
introduced at     the conducting screw  
near 7b7 wherefrom it proceeds to the   
quicksilver1 the movable angle1 the     
platina plate and the     complementary 
telegraph to#bi the conducting screw    
7s74 ,from     here it goes through the 
conducter to the other station ,b and   
from there returns to the battery4      
8,the apparatus ,b1 a sonorous box on   
the cover of which is     placed the    
wire-spiral with the steel axis1 wich   
will be     magnetic when the current   
goes through the spiral4 ,a second      
little box is fixed on the first one1   
and laid down on the     steel axis to  
increase the intensity of the reproduced
     sounds4 ,on the small side of the  
lower box you will find the             

correspondent part of the complementary 
telegraph4      8,if a person sing at   
the station ,a1 in the tube 7x7 the     
vibrations of air will pass into the box
 and move the     membrane above2       
thereby the platina foot 7c7 of the     
movable     angle will be lifted up and 
will thus open the stream at     every  
condensation of air in the box4 ,the    
stream will be     re-established at    
every rarefaction4 ,for this manner the 
steel axis at station ,b will be        
magnetic once for every full            
vibration2 and as magnetism never enters
 nor leaves a metal     without         
disturbing the equilibrium of the atoms1
 the steel-axis     at station ,b must  
repeat the vibrations at station ,a and 
thus     reproduce the sounds which     
caused them4      8,any#cj sound will be
 reproduced1 if strong enough to set    
the membrane in motion4      8,the      
little telegraph1 which you will find on
 the side of the     apparatus is very  
usefull and agreable for to give signals

     between both of the correspondents4
 ,at every opening of the     stream and
 next following shutting the station ,a 
will hear a     little clap produced by 
the attraction of the steel spring4     
,another little clap will be heard at   
station 7,b7 in the     wire-spiral4 ,by
 multiplying the claps and producing    
them in     different measures you will 
be able as well as ,i am to get         
understood by your correspondent4       
8,i am to end1 ,sir1 and ,i hope1 that  
what ,i said will be     sufficient to  
have a first try2 afterward you will get
 on quite     alone4      8,i am1 ,sir1 
8,your most obediant ,servant1          
8,ph4 ,reis4        8,friedrichsdorf1   
#ac_/g1 #fc40   #i4 ,,reis',s           
,,prospectus4  ,the following           
8,prospectus0 of instructions was drawn 
up by ,reis to accompany the ,telephones
 which were sold by ,herr ,wilh4 ,albert
 of ,frankfort4 ,the author of this book
 is in possession of original copies1 of
 which a number are extant4 ,the        

8,prospectus0 was also reprinted in its 
entirety at page #bda of ,professor     
,pisko's book #8,die neueren ,apparate  
der ,akustik1' published at ,vienna in  
#ahfe4   ,,telephon4  ,each apparatus   
consists1 as is seen from the above     
illustration1 of two parts3 the         
,telephone proper1 ,a1 and the          
,reproduction apparatus ,receiver1 ,c4  
,these two parts are placed at such a   
distance from each other1 that singing1 
or the tones of a musical instrument1   
can be heard from one station to the    
other in no way except through the      
apparatus itself4  ,both parts are      
connected with each other1 and with the 
battery1 ,b1 like ordinary telegraphs4  
,the battery must be capable of         
effecting the attraction of the armature
 of the electromagnet placed at the side
 of station ,a 7#c-d six-inch ,bunsen's 
elements suffice for several hundred    
feet distance74  ,the galvanic current  
goes then from ,b to the screw1 d1      
thence through the copper strip to the  

little platinum plate at the middle of  
the membrane1 then through the foot1 c1 
of the angular piece to the screw1 b1 in
 whose little concavity a drop of       
quicksilver is put4 ,from here the      
current then goes through the little    
telegraph apparatus1 e-f1 then to the   
key of station ,c1 and through the      
spiral past i back to ,b4               
,illustration3 ,fig4 #bi4  ,if now      
sufficiently strong tones are produced  
before the sound-aperture1 ,s1 the      
membrane and the angle-shaped little    
hammer lying upon it are set in motion  
by the vibrations2 the circuit will be  
once opened and again closed for each   
full vibration1 and thereby there will  
be produced in the iron wire of the     
spiral at station ,c the same number of 
vibrations which there are perceived as 
a tone or combination of tones 7chord74 
,by imposing the little upper case      
7,oberkstchen7 firmly upon the axis of  
the spiral the tones at ,c are greatly  
strengthened4  ,besides the human voice 

7according to my experience7 there also 
can be reproduced the tones of good     
organ-pipes from ,f--c' and those of a  
piano4 ,for the latter purpose ,a is    
placed upon the sounding-board of the   
piano4 7,of thirteen triads 7,dreiklnge7
 a skilled experimentor could with all  
exactness recognise ten74  ,as regards  
the telegraph apparatus placed at the   
side1 it is clearly unnecessary for the 
reproduction of tones1 but it forms a   
very agreeable addition for convenient  
experimenting4 ,by means of the same1 it
 is possible to make oneself understood 
right well and certainly by the other   
party4 ,this takes place somewhat in the
 following manner3 ,after the apparatus 
has been completely arranged1 one       
convinces oneself of the completeness of
 the connexion and the strength of the  
battery by opening and closing the      
circuit1 whereby at ,a the stroke of the
 armature is heard1 and at ,c a very    
distinct ticking4  ,by rapid alternate  
opening and closing at ,a it is asked at

 ,c whether one is ready for            
experimenting1 whereupon ,c answers in  
the same manner4  ,simple signals can by
 agreement be given from both stations  
by opening and closing the circuit one1 
two1 three1 or four times2 for          
example3--                  #a beat     
,sing4                 #b beats  ,speak1
 c4  ,i telegraph the words thus--that  
,i number the letters of the alphabet   
and then transmit their numbers--       
#a beat   a4                 #b beats   
b4                 #c       c4          
#d       d4                 #e       e1 
c4  z would accordingly be designated by
 twenty-five beats4  ,this number of    
beats would1 however1 appear wasteful of
 time1 and would be uncertain in        
counting1 wherefore ,i employ for every 
five beats a dactyl-beat                
7,dactylusschlag71 and there results    
,illustration3--  for e4                
,illustration3--  and one beat for f1 c4
  z1  ,illustration3-- 1-- 1-- 1-- 1--  
which is more quickly and easily        

executed and easier to understand4  ,it 
is still better if the letters are      
represented by numbers which are in     
inverse proportion to the frequency of  
their occurrence4                       
,phil4 ,reis1       ,teacher at ,l4 ,f4 
,garnier's ,institute for boys4         
,friedrichsdorf1 near                   
,homburg-by-the-,height1       ,august  
#ahfc4  ,the foregoing 8,prospectus0 was
 accompanied by a further document      
printed as a postscript by ,reis1 at the
 top of which the figure of the         
instrument was repeated1 and which ran  
as follows3--      8,p4 ,p41            
8,since two years ago ,i succeeded in   
effecting the possibility     of the    
reproduction of tones by the galvanic   
current1 and in     setting up a        
convenient apparatus therefor1 the      
circumstance     has found such a       
recognition from the most celebrated men
 of     science1 and so many calls to   
action have come to me1 that ,i     have
 since striven to improve my originally 

very incomplete     apparatus1 so that  
the experiments might thereby become    
accessible to others4      8,i am now in
 the position to offer an apparatus     
which fulfils     my expectations1 and  
with which each physicist may succeed in
     repeating the interesting          
experiments concerning reproduction     
of tones at distant stations4      8,i  
believe ,i shall fulfil the wish of many
 if ,i undertake to     bring these     
improved instruments into the possession
 of the     physical cabinets4 ,since   
the preparation of the same requires    
a complete acquaintance with the leading
 principles and a     tolerable         
experience in this matter1 ,i have      
decided myself to     prepare the most  
important parts of the same1 and to     
leave the     fashioning of the         
accessory parts1 as also of the external
     adornments1 to the mechanician4    
8,the distribution of the same ,i have  
made over to ,herr ,j4     ,wilh4       
,albert1 mechanician1 in                

,frankfort-on-the-,main1 and have       
placed him in the position to deliver   
these instruments in     two qualities1 
differing only in external adornment1 at
 the     prices of #ba florins and #ad  
florins 7#ab thalers and #h thalers     
current71 inclusive of packing4         
,moreover1 the instruments can     also 
be obtained direct from me at the same  
prices1 upon a cash     remittance of   
the amount4      8,each apparatus will  
be tested by me before sending off1 and 
will then be furnished with my name1 an 
order-number1 and with     the year of  
manufacture4      8,friedrichsdorf1 near
 ,homburg-by-the-,height1               
8in ,august #ahfc4                      
8,phil4 ,reis1          8,teacher at ,l4
 ,f4 ,garnier's ,institute for ,boys40  
,in ,september of the same year the     
telephone was shown by ,prof4 ,r ,bttger
 at the meeting of the ,german          
,naturalists' ,association              
7,naturforscher71 which met on that     
occasion at ,stettin4 ,little or nothing

 is known of what took place at this    
exhibition1 but ,professor von          
,feilitzsch1 of the neighbouring        
,university of ,greifswald1 has informed
 the author of this work that the       
,telephone there shown was of the form  
figured in ,reis's ,prospectus 7p4 #hf71
 and that ,reis claimed at that time to 
be able to transmit words by his        
instruments4 ,in the same autumn the    
following notice appeared in ,bttger's  
#8,notizblatt1' and was copied thence   
into ,dingler's #8,journal1' and other  
scientific papers4   #aj4 ,,on ,,the    
,,improved ,,telephone4      ,translated
 from the original notice which appeared
 in     ,bttger's #8,polytechnisches    
,notizblatt1' #ahfc1 ,no4 #ae1 p4 #bbe1 
and in ,dingler's #8,polytechnisches    
,journal1' #ahfc1 vol4 clxix4     p4    
#cii4  ,at the meeting of the ,physical 
,society of ,frankfort-on-the-,main1 on 
the #dth of ,july1 a member of this     
,society1 ,herr ,ph4 ,reis1 of          
,friedrichsdorf1 near                   

,homburg-vor-der-,hhe1 exhibited some of
 his improved ,telephones 7means for the
 reproduction of tones at any desired   
distance by the galvanic current74 ,it  
is now two years since ,herr ,reis first
 gave publicity to his apparatus1#ca and
 though even already at that time the   
performances of the same in their simple
 artless form were capable of exciting  
astonishment1 yet they had then the     
great defect that experimenting with    
them was only possible to the inventor  
himself4 ,the instruments exhibited in  
the above-named meeting scarcely        
reminded one of the earlier ones4 ,herr 
,reis has also striven to give them a   
form pleasing to the eye1 so that they  
may now occupy a worthy place in every  
,physical ,cabinet4 ,these new apparatus
 may now also be handled by every one   
with facility1 and work with great      
certainty4 ,melodies gently sung at a   
distance of about #cjj feet were        
repeated by the instrument which was set
 up1 much more distinctly than          

previously4 ,the scale was reproduced   
especially sharply4 ,the experimenters  
could even communicate words to one     
another1 though certainly indeed only   
such as had often been heard by them4   
,in order moreover that others who are  
less accustomed to experimenting may be 
able to understand one another through  
the apparatus1 the inventor has placed  
on the side of the same a little        
arrangement1#cb which according to his  
explanation is completely sufficient1   
the speed of communication of which is  
indeed not so great as that of modern   
,telegraphs1 but which works quite      
certainly1 and requires no special skill
 on the part of the one experimenting   
with it4  ,we would bring to the notice 
of gentlemen who are professional       
physicists that the inventor of these   
interesting pieces of apparatus now has 
them prepared for sale under his        
oversight 7the important parts he makes 
himself71 and the same can be procured  
from him direct1 or through the         

mechanician1 ,mr4 ,wilhelm ,albert1 of  
,frankfort-on-the-,main1 at #ad and at  
#ba florins1 in two qualities1 differing
 only in external adornment4  ,a review1
 written by ,dr4 ,rber of ,berlin1 of   
this and other articles relating to the 
,telephone appeared subsequently in the 
#8,fortschritte der ,physik1' #ahfc1 p4 
#if4  ,another consequence of the       
publicity thus given to the ,telephone  
was the appearance of an article on that
 instrument1 under the title of 8,der   
,musiktelegraph10 in a popular          
illustrated weekly family paper1 #8,die 
,gartenlaube1' published at ,leipzig4   
,this article1 from the pen1 it is      
believed1 of ,dr4 ,oppel of ,frankfort1 
is made up chiefly of slightly altered  
extracts from the previously quoted     
documents4 ,the form of the instrument  
described is identical with that        
described in ,reis's #8,prospectus1' and
 the figure given in the                
#8,gartenlaube1' ,no4 #ea1 p4 #hji1 is a
 reprint1 apparently from the same      

wood-block of the figure which heads    
,reis's ,prospectus1 and which is       
reproduced on p4 #hf of this work4 ,the 
only passage of further interest is a   
brief sentence relating to the          
exhibition of the ,telephone at the     
,german ,naturalists' ,assembly at      
,stettin in #ahfc1 and is as follows3-- 
#aa4 8,now in order also to give to a   
still wider circle1 especially to       
technologists 7,fachmnnern71 the        
opportunity of witnessing with their own
 eyesight the efficiency of this        
apparatus1--lately1 in fact essentially 
improved1--,professor ,bttger of        
,frankfort-on-the-,main exhibited       
several experiments therewith at the    
meeting of the ,german ,naturalists     
7,naturforscher7 and ,physicians        
recently held at ,stettin1 in the       
,section for ,physics2 which experiments
 would certainly have been crowned with 
still greater success if the place of   
meeting had been in a less noisy        
neighbourhood1 and had been filled with 

a somewhat less numerous audience40     
,the next extract is a brief record from
 the ,report of a scientific society    
meeting in ,giessen1 which during the   
,austro-,prussian war of #ahff had      
become disorganised1 and which in #ahfg 
published a condensed account of its    
proceedings for the preceding years4    
,amongst those proceedings was a lecture
 by the late ,professor ,buff1 at which 
,reis's ,telephone was shown1 and at    
which ,reis himself is believed to have 
been present4   #ab4 ,,extract ,,from   
,,the #8,,twelfth ,,report ,,of ,,the   
,,upper-,,hessian ,,association ,,for   
,,natural ,,and ,,medical ,,science1'   
7#8,oberhessische ,gesellschaft fr      
,natur und ,heilkunde1'7 ,giessen1      
,february #ahfg4  ,p4 #aee4 ,report on  
the doings and condition of the         
,association from the #ast of ,july1    
#ahfc1 to the #ast of ,july1 #ahfe1 by  
,herr ,gymnasiallehrer ,dr4 ,w4 ,diehl4 
444 ,on the #acth of ,february #ahfd1   
#8,on the ,tones of the ,magnet1 with   

,application to the ,telephone1 with    
experiments1' by ,professor ,buff4      
,,exhibition ,,of ,,the ,,telephone ,,to
 ,,the ,,naturalists' ,,association ,,of
     ,,germany4 7,,deutsche             
,,naturforscher ,,versammlung47  ,by far
 the most important of all the public   
exhibitions given by ,reis of his       
,telephone1 was that which took place on
 the #bast of ,september1 #ahfd1 at     
,giessen1 on the occasion of the meeting
 of the ,german ,naturalists'           
,association 7,versammlung ,deutsche    
,naturforscher74 ,here were assembled   
all the leading scientific men of       
,germany1 including the following       
distinguished names1 many of whom are   
still living3--,prof4 ,buff 7,giessen71 
,prof4 ,poggendorff 7,berlin71 ,prof4   
,bohn 7,frankfurt-a4-,m41 now of        
,aschaffenburg71 ,prof4 ,jolly          
7,munich71 ,dr4 ,geissler 7,bonn71      
,prof4 ,weber 7,gttingen71 ,prof4       
,plcker 7,bonn71 ,prof4 ,quincke        
7,heidelberg71 ,prof4 ,dellmann         

7,kreutznach71 ,prof4 ,bttger           
7,frankfurt-a4-,m4 and ,mainz71 ,prof4  
,kekule 7,bonn71 ,prof4 ,gerlach        
7,erlangen71 ,dr4 ,j4 ,frick            
7,carlsruhe71 ,dr4 ,f4 ,kohlrausch      
7,wrtzburg71 ,prof4 ,reusch 7,tbingen71 
,prof4 ,j4 ,mller 7,freiburg71 ,prof4   
,helmholtz 7,heidelberg71 ,prof4 ,melde 
7,marburg71 ,prof4 ,kopp 7,marburg71    
,prof4 ,a4 ,w4 ,hoffmann 7,london1 now  
of ,berlin71 ,mons4 ,hofmann 7,paris1   
optician71 ,hofrath ,dr4 ,stein         
7,frankfurt-a4-,m471 ,dr4 ,w4 ,steeg    
7,homburg71 ,mons4 ,hartnack 7,paris1   
and of ,pottsdam71 ,prof4 ,g4 ,wiedemann
 7,basel1 now of ,leipzig71 ,e4 ,albert 
7,frankfurt-a4-,m41 mechanician71 ,dr4  
,thudichum 7,london71 ,w4 ,schultze     
7,york1 apothecary71 ,dr4 ,j4 ,barnard  
,davis 7,shelton71 ,e4 ,j4 ,chapman     
7,london1 chemist71 ,dr4 ,l4 ,beck      
7,london1 chemist71 ,prof4 ,chas4 ,j4   
,himes 7,u4,s4,a41 chemist71 ,e4 ,w4    
,blake 7,new ,haven1 ,u4,s4,a41         
student71 ,c4 ,g4 ,wheeler 7,united     

,states ,consul in ,nrnberg71 and many  
others4 ,dr4 ,c4 ,bohn 7now of          
,aschaffenburg7 was ,secretary of the   
,association1 and also ,secretary of the
 ,section of ,physics4 ,the meetings of 
this ,section were held in the          
,laboratory of ,professor ,buff4 ,reis  
came over from ,friedrichsdorf          
accompanied by his young brother-in-law1
 ,philipp ,schmidt4 ,a preliminary trial
 on the morning of that day was not very
 successful1 but at the afternoon       
sitting1 when communications were made  
to the ,section by ,prof4 ,buff1 by     
,reis himself1 and by ,prof4            
,poggendorff1 the instrument was shown  
in action with great success4 ,reis     
expounded the story how he came to think
 of combining with the electric current 
interruptor a tympanum in imitation of  
that of the human ear1 narrating his    
researches in an unassuming manner that 
won his audience completely to him2 and 
the performance of the instrument was   
received with great applause4 ,various  

professors essayed to experiment with   
the instrument1 with varying degrees of 
success according to whether their      
voices suited the instrument or not4    
,amongst these were ,prof4 ,bttger and  
,prof4 ,quincke of ,heidelberg1 whose   
account of the occasion is to be found  
on p4 #aab4 ,dr4 ,bohn1 the ,secretary  
of the ,section1 wrote for the          
#8,journal' 7,tagesblatt71 issued daily1
 the following notice4   #ac4 ,,extract 
,,from ,,the ,,report ,,of ,,the        
,,german ,,naturalists' ,,society1      
,,held ,,at ,,giessen 7#ahfd74          
8,afternoon sitting on #bast ,september1
 #ahfd4  8,prof4 ,buff speaks about the 
tones of iron and steel rods when       
magnetised1 and exhibits the            
corresponding experiments4  8,dr4 ,reis 
demonstrates his ,telephone1 gives      
thereupon an explanation and the history
 of this instrument4  8,prof4           
,poggendorff produces tones in a metal  
cylinder1 the slit up edges of which    
touch one another firmly1 and which is  

placed loosely round an induction-bobbin
 through which there goes an interrupted
 current40  ,this occasion was the      
crowning point of ,philipp ,reis's      
career1 and might have proved of even   
greater importance but for two causes3  
the inventor's precarious health1 and   
the indifference with which the         
commercial world of ,germany viewed this
 great invention4 ,where the keen       
insight of ,reis contemplated the vast  
possibilities opened out by the         
invention of a new mode of              
inter-communication1 others saw only an 
ingenious philosophical toy1 or at best 
a pleasing illustration of certain known
 principles of acoustic and electric    
science4 ,and in spite of the momentary 
enthusiasm which the exhibition of the  
,telephone had evoked1 the interest in  
it dwindled away4 ,a few of the public  
journals of that date1 noticed the      
invention in eulogistic terms and spoke 
of the prospect it afforded of          
communication between distant friends   

and of simultaneous concerts being given
 in different towns1 all transmitted    
telephonically from one orchestra4 ,but 
the invention came too early4 ,the      
public mind was not yet prepared to take
 it up1 and the enthusiasm died away4   
,still in a few of the more important   
books on ,physics1 ,acoustics1 and      
,electricity1 the matter continued to   
receive attention4 ,in the well-known   
,mller-,pouillet's #8,textbook of       
,physics' 7,lehrbuch der ,physik7 edited
 by ,professor ,j4 ,mller2 in the       
#8,technical ,physics' of ,hessler1 of  
,vienna1 edited by ,professor ,pisko2 in
 ,pisko's #8,recent ,apparatus of       
,acoustics1' and particularly in ,kuhn's
 admirable #8,handbook of ,applied      
,electricity1' the ,telephone was       
accepted as a definite conquest of      
science1 and was described and figured4 
,from the works named we transcribe the 
extracts which follow1 and which        
sufficiently explain themselves4   #ad4 
,,extract ,,from ,m,,ller-,,pouillet',s 

#8,,textbook ,,of ,,physics ,,and       
,,meteorology' 7,,lehrbuch ,,der        
,,physik ,,und ,,meteorologie74         
,published at ,brunswick1 ,sixth ed41   
#ahfc1 vol4 ii4 page #ceb1 fig4 #cbe2   
and ,seventh ed41 #ahfh1 vol4 ii4 pages 
#chf-chh1 figs4 #cdh-cej4 ,the following
 translation is from the latter edition4
  8,this tone 444 has ,reis used for the
 construction of his ,telephone4        
8,figure #cdhcc exhibits ,reis's        
interrupting apparatus4 ,in the lid of a
 hollow cube of wood ,a1 a circular     
opening is made1 which is closed by an  
elastic membrane 7pig's lesser          
intestine7 strained over it4 ,upon the  
centre of this membrane is glued a      
little plate of platinum1 which stands  
in conductive communication with the    
clamping-screw a by means of a quite    
thin little strip of metal f 7distinctly
 visible in ,fig4 #cdi7 ,fig4 #ca4      
8,upon the middle of the little platinum
 plate1 rests a short little platinum   
pencil1 which is fastened at g to the   

under-side of the strip of tin-plate h g
 i1 one end of which1 h1 rests upon the 
little metal pillar l1 while a little   
platinum spike fastened upon its        
under-side at i1 dips into the hollow of
 the little metal pillar k1 containing  
some quicksilver4 ,the clamping-screw b1
 is put into conductive communication   
with the little metal pillar k4  8,from 
one pole of the battery there goes a    
conducting-wire to the clamping-screw a 
of the interrupting apparatus ,fig4 #cdh
 ,fig4 #cj1 from the other pole of the  
same there goes a wire to the           
clamping-screw d of the reproducing     
apparatus1 ,fig4 #cej ,fig4 #cb1 which  
is to be presently described4 ,the      
clamping-screw c1 of this apparatus1 is 
connected by a wire with b1 ,fig4 #cdh  
,fig4 #cj4 ,the clamping-screws c and d 
are connected with the ends of the wire 
of the small magnetising spiral ,m1     
,fig4 #cej ,fig4 #cb2 with the connexion
 described above1 the current of the    
current-generator 7battery7 goes1       

therefore1 through the spiral ,m4  8,as 
soon now as the sound-waves of an       
adequately powerful tone enter through  
the mouth-piece ,s into the hollow cube 
,a1 the elastic membrane which closes   
this at the top is set into vibrations4 
,each wave of condensation on entering  
lifts the little platinum plate together
 with the little spike which sits upon  
it2 but if the membrane swings          
downwards1 the tin-piece h g i1 with the
 little spike at i1 cannot follow it    
quick enough2 there therefore occurs    
here1 at each vibration of the membrane1
 an interruption of the current which   
lets itself be recognised by a little   
spark appearing at the place of         
interruption4  ,illustration3 ,fig4 #cj4
  ,illustration3 ,fig4 #ca4             
,illustration3 ,fig4 #cb4  8,now in the 
spiral ,m is stuck a knitting-needle1   
which1 as the figure shows1 is fastened 
into a sounding-board4 ,a lid provided  
with second sounding-board may be       
clapped over the spiral1 and the tone be

 thereby greatly strengthened4  8,if    
now1 tones are produced before the      
mouth-piece ,s1 whilst one sings into   
the same or whilst one blows            
organ-pipes1 one at once hears at the   
reproducing apparatus a peculiar        
creaking noise which is independent of  
the pitch of the tones produced at the  
interrupting apparatus1 but1 beside     
this1 those tones are themselves        
reproduced by the steel wire distinctly 
perceptibly1 and indeed ,reis found that
 this is the case for all tones between 
,f and f''4  8,in ,reis's experiments   
the interrupting apparatus was #cjj feet
 distant from the spiral1 and was indeed
 set up in another house with closed    
doors4 ,but since the length of the     
conducting wire can be extended just as 
far as in direct telegraphy1 ,reis gave 
to his apparatus the name ,telephone    
7,jahresbericht des physikalischen      
,vereins zu ,frankfurt-a4-,m4 fr        
#ahfj_/fa740   #ae4 ,,extract ,,from    
,,pisko',s #8,,die ,,neueren ,,apparate 

,,der ,,akustik4'  ,this book1 #8,the   
more recent ,apparatus of ,acoustics1'  
by ,dr4 ,francis ,joseph ,pisko1        
,professor of ,physics in the           
,gewerbeschule in ,vienna1 was published
 at ,vienna in #ahfe4 ,at that time the 
novelties in acoustics were ,knig's     
apparatus for the graphic study of      
sounds1 ,knig's manometric flames1      
,schaffgotsch's singing flames1         
,helmholtz's #8,researches on the       
,quality of ,sounds1' ,duhamel's        
,vibrograph1 ,scott and ,knig's         
,phonautograph1 and ,reis's ,telephone4 
,the account given of the latter is more
 detailed in some respects than any     
other published at the time4  ,page     
#id4--,,principle ,,of ,,the            
8,,telephon0 ,,of ,,reis4  #ea4 7a47    
,allied to the ,membrane ,phonautograph 
is the 8,telephon0 of ,reis#cd 7,fig4   
#cc74 ,upon the little membrane1 m m1 in
 the middle1 is fastened with adhesive  
wax the round end s of a light strip of 
platinum1 n s1 so that the platinum     

strip can join in with all the          
vibrations of the membrane4 ,very near  
to the central end1 s1 of the little    
platinum strip1 n s1 a platinum spike   
stands1 in such a way that it is brought
 into contact1 by the vibrations of the 
membrane1 with the platinum strip that  
vibrates with the latter4 ,suppose now  
that the outer end1 n1 of the platinum  
strip and the platinum spike are        
connected with the poles of a galvanic  
battery1 then1 by the vibration of the  
membrane the galvanic current will1     
according to the phase of the vibration1
 be alternately established and         
interrupted4 ,inserted in this circuit1 
an electro-magnetic bell1 or an         
electro-magnetic telegraph1 will give   
signals to great distances that somebody
 is speaking2#ce though1 obviously1 it  
cannot inform what is being spoken4     
,illustration3 ,fig4 #cc4  7b47 ,as is  
known1 an iron wire around which flow   
rapidly-interrupted powerful galvanic   
currents1 is thereby thrown into tones  

which1 according to circumstances1 may  
be longitudinal or transverse or both   
together4 ,such an iron wire1 lying in a
 multiplying wire-coil1 ,g1 ,reis       
inserted at the second receiving        
station1 ,c4 ,the wire emitted sounds   
when the membrane was set into          
vibrations by singing or speaking 7at   
,s1 ,fig4 #cc7 into the hollow cubical  
piece ,a4 ,in the investigations made by
 me with the telephone1 the rod 7of     
iron7 never altered the pitch of its    
tone with the most different kinds of   
tones and clangs1 and always gave only  
the rhythm of the words sung or spoken  
into the piece ,a 7the transmitter7 at  
,s4 ,usually the air of the song that   
was sung could be recognised by its     
rhythm4#cf ,the special researches on   
these points follow in paragraph #ec4   
,however1 it is so far clear that there 
is still plenty of time yet before we   
have the simultaneous concerts1 and the 
transmission of singing to different    
towns1 as the daily newspapers have     

sanguinely expected4 ,the apparatus of  
,reis is certainly a 8,telephone0 but   
not a 8,phonic ,telegraph40 ,the single 
means of transmission for song and      
speech--and that only for moderate      
distances--remains the old familiar     
speaking-tube4 ,nevertheless1 the       
experiment of ,reis must ever be        
reckoned amongst the most beautiful and 
interesting of school-experiments4 ,and 
since the means for this are so simple1 
the apparatus of ,reis will certainly   
find a speedy entrance into educational 
establishments that are only moderately 
endowed4 ,it is easily proved that the  
tones of the wire in the telephone do   
not arise from acoustic conduction1 for 
by cutting out the coil from the circuit
 the tones immediately cease4      #a4  
,the ,telephone of ,reis originally     
consisted of a cube of wood     with a  
conical boring4 ,the smaller opening was
 strained over     with a membrane4 ,a  
knitting-needle which served for a      
sounding     wire projected about #b    

inches on each side of the multiplying  
coil1 and lay upon the two bridges of a 
sounding-box4 ,the     surrounding helix
 consisted of six layers of thin wire4  
,fig4     #cc shows the ,telephone as it
 is constructed at the present     time 
by the mechanician1 ,albert1 in         
,frankfort1 and by the     mechanician1 
,hauck1 in ,vienna1 according to the    
directions of     the inventor4         
99       99       99       99       99  
#eb4 ,details about the ,telephone4     
7a47 ,the same 7,fig4 #cc7 consists in  
its essentials3      #a4 ,of a          
transmitter1 ,a2      #b4 ,of a         
receiver1 ,c2      #c4 ,of a galvanic   
battery1 ,b1 and lastly1      #d4 ,of   
the conducting wires that connect them4 
7b47 ,the transmitter1 ,a1 is           
essentially a parallelepipedal body of  
wood4 ,the upper part1 u x1 of it is cut
 out of one piece of wood with square   
cross-section1 the side1 x x1 of which  
measures #i centimetres1 and its height1
 u x1 #bh centimetres4  ,this part is   

moveable upon a hinge on the lower      
little box1 ,a ,a4 ,if the cover1 x u1  
is laid back1 one sees that a small     
circle of #ci centimetres diameter has  
been cut out in the same4 ,into this    
hole passes a brass collar with a flange
 #h millimetres broad1 which is         
furnished at one side with a groove like
 a pulley4 ,over the collar there is    
stretched the membrane1 m m1 by means of
 a silk thread lying in the shoulder of 
the same4 ,this circular membrane is    
surrounded by a wider circular aperture1
 b b1  #he centimetres4 ,a shovel-shaped
 little strip of platinum1 n s1 lies    
7over it7 leading to the brass          
binding-screw1 d1 with the circular     
part1 s1 falling upon the centre of the 
membrane4  ,by means of some sealing-wax
 this circular part is fastened to the  
membrane1 and thereby compelled to take 
part in the vibrations of the same4 ,the
 further transmission of the galvanic   
current from the centre takes place by  
means of a platinum or steel point      

resting in a cup of mercury1 which is   
extended in a screw1 which transmits the
 current farther4 ,the point a serves as
 a support for the angular hook1 a s b1 
which in general is supported like a    
tripod1 in order that the point of      
contact1 s1 may remain as constant as   
possible4 ,the hook1 a s b1 is simply   
struck with a hole at a upon a          
projecting point1 and lies upon a       
broader under part4 ,from b the galvanic
 circuit proceeds by means of an        
overspun wire to the brass key e 7,a1   
,fig4 #cc71 and from there farther in   
the direction represented by the arrow4 
,the lower part ,a ,a of the transmitter
 is put together of thin wood and forms 
a parallelepiped1 whose height  #fh cm41
 and whose width  #gg cm4 ,an inclined  
mouthpiece of tin with funnel-shaped    
opening serves to receive the tones4    
,the longer side of this mouthpiece     
measures #fg cm41 the shorter #dg cm42  
the longer diameter of the widening     
measures #gae cm41 the shorter diameter 

#ge cm41 and finally the diameter of the
 narrow tube #ci cm4      ,it is clear  
that1 if necessary1 the platinum strip  
can be     replaced by a strip of thin  
sheet-brass1 the platinum or steel      
points by iron4 ,only in this case the  
points of contact must be     oftener   
cleaned to a metallic polish4  7c47 ,the
 receiver 7,zeichengeber7 ,c is in      
general a double resonant box1 whose    
upper part1 8the cover10 is moveable    
upon two hinges1 and can be laid back4  
,the length of this cover is #afd cm41  
its width #ie cm41 and its height #cb   
cm4 ,the length of the lower box        
measures #bbi cm41 its width #if cm41   
and its height #be cm4 ,the under part  
of the resonant box bears two wooden    
bridges1 which stand about #gd cm4 from 
each other1 and which serves as supports
 for the #bae cm4 long1 and #ji cm4     
thick iron needle destined for          
reproducing the tones4 ,the length of   
spiral wound over the needle1 and       
designed for making an electro-magnet of

 the same1 is #ae cm4 ,the wooden covers
 of both parts1 scraped as thin as      
possible1 and the greatest breadth of   
the circular holes shown in the figure1 
measures #ac mm4  7d47 ,for a battery   
one can successfully use a small ,smee's
 consisting of four elements1 or two    
larger ,bunsen's cells4  ,the conductor 
must be at least sufficiently long that 
one cannot perceive the tones that are  
produced4 ,for correspondence between   
the two stations the inventor has       
employed the electro-magnetic telegraph 
arrangement1 e v g h1 seen in the       
mechanism1 and easily understood4 ,an   
agreement in reference to corresponding 
signs can be easily arranged1 and the   
simplest way is to accept the signals   
arranged by the inventor4 7,see         
#8,prospectus4'7  ,the receiver ,c      
gives1 when the key e is pressed1 the   
corresponding telegraphic signals by    
means of tones in the rod ,e ,e1 while  
at the transmitter1 ,a1 the             
electro-magnet v gives the signals by   

means of the springy armature z4        
#ec4 ,experiments with the ,telephone4  
7a47 ,as soon as one brings the mouth to
 the funnel ,s and sings1 the membrane  
of the transmitter1 ,a1 vibrates in a   
corresponding manner1 and the iron rod1 
,e ,e1 at the second station begins to  
give forth a tone4 ,every time a spark  
is seen at the first station s1 the rod 
at the other station certainly gives    
forth a tone4 ,the same is true when one
 hears the peculiarly snarling tone     
which arises from the stroke of the     
vibrating platinum strip against the    
spike of angular hook resting upon it4  
,the appearance of these sparks or of   
the peculiar snarling at the transmitter
 ,a gives the sign to the observers at  
the station ,a that the rod in ,c is    
giving a tone4 ,tones and melodies which
 were sung into the sound aperture1 and 
especially sounds in which the teeth and
 bones of the head also vibrated        
7so-called humming tones71 always evoked
 a tone in the rod or needle ,e ,e1 and 

indeed1 as already mentioned 7 #ea71    
without change in the pitch1 but only   
with the reproduction of the rhythm of  
the respective song or words4  ,the     
pitch of the tone excited at ,c in the  
rod ,e ,e was in the apparatus at my    
disposal h2 its strength not very great 
and its clang snarly1 similar to that of
 a lightly sounding reed-whistle1       
somewhat like that of a child's wooden  
trumpet4 ,the cuticle lying about the   
heart of the smaller and even the larger
 mammals 7from calves1 c47 makes the    
best membranes4 ,goldbeater's-skins     
reproduce only the deeper tones4 ,the   
cover of the sounding-box appeared in my
 apparatus superfluous1 and indeed the  
tone was somewhat stronger without the  
cover4      #a4 ,in experiments with the
 telephone1 one must look closely     as
 to whether the ends of the platinum    
strip is still     fastened to the      
membrane1 and one must1 if necessary1   
press     upon the membrane4 ,if the    
strip will no longer stick1 heat     a  

knife-blade1 touch a small piece of     
sealing wax with it1     and carry thus 
the melted sealing-wax to the under side
 of     the round end of the            
platinum-strip1 n s4 ,then press it     
immediately on the membrane1 m m4       
,ph4 ,reis showed his apparatus in very 
primitive form for     the first time in
 ,october1 #ahfa1 to the ,physical      
,society at     ,frankfort-on-the-,main2
 on ,july #dth1 #ahfc1 before the same  
society1 he showed the form represented 
in ,fig4 #cc4 ,this time     he         
experimented upon a distance of #cjj    
feet4 ,professor ,boettger     brought  
the apparatus before the                
,naturforscher-,versammlung at          
,stettin 7#ahfc7 in the section for     
,physics4   #af4 ,,hessler',s           
#8,,text-,,book ,,of ,,technical        
,,physics1' vol4 i4 p4 #fdh4  ,next in  
chronological order comes a notice of   
the ,telephone in ,hessler's #8,lehrbuch
 der technischen ,physik1' edited by    
,prof4 ,pisko1 and published at ,vienna 

in #ahff4 ,the brief account given in   
this work adds nothing to the accounts  
previously given1 and is evidently      
written by some person ignorant of      
,reis's own work1 for beside omitting   
all mention of the transmission of      
speech by the instrument1 or of its     
being constructed upon the model of the 
human ear1 the writer appears not even  
to know how to spell ,reis's name1#cg   
and speaks of him as 8,reuss40   #ag4   
,,kuhn',s #8,,handbook ,,of ,,applied   
,,electricity1'  7#8,handbuch der       
,angewandten ,elektricittslehre1' von   
,carl ,kuhn71 being vol4 xx4 of         
,karsten's #8,universal ,encyclopdia of 
,physics' 7,karsten's #8,allgemeine     
,encyclopdie der ,physik'74  ,karsten's 
#8,encyclopdia of ,physics1' which has  
been for many years a standard work of  
reference1 both in ,germany and in this 
country1 consists of a number of        
volumes1 each of which is a complete    
treatise1 written by the very highest   
authorities in ,germany4 ,thus          

,helmholtz contributed the volume on    
,physiological ,optics1 ,lamont that on 
,terrestrial ,magnetism1 whilst the     
names of ,dr4 ,brix1 ,professor von     
,feilitzsch1 and others1 are included   
amongst the authors4 ,carl ,kuhn1 who   
wrote vol4 xx41 was ,professor in the   
,royal ,lyceum of ,munich1 and member of
 the ,munich ,academy4 ,kuhn's volume on
 #8,applied ,electricity1' published in 
#ahff1 is to be found on the shelves of 
almost every library of any pretensions 
in ,great ,britain4 ,the account given  
therein of ,reis's ,telephone is        
interesting1 because it describes two   
forms1 both of transmitter and of       
receiver4 ,in fact the descriptions and 
figures are taken almost directly from  
von ,legat's ,report 7p4 #gj71 and from 
,reis's ,prospectus 7p4 #hg74 ,the      
extract translated below includes all   
the matter that is of importance4  ,p4  
#ajag4 ,the researches established by   
,reis on the #bfth of ,october1 #ahfa1  
in ,frankfurt#ch have already shown that

 if the current interruptions follow one
 another almost continuously and very   
rapidly1 in a spiral arranged with a    
thin iron core1 the iron wire can be set
 into longitudinal vibrations1 whereby  
therefore the same is constrained to    
reproduce tones of different pitch4     
99       99       99       99       99  
,here follows a reference to ,petrina's 
,electric ,harmonica4         99        
99       99       99       99  ,from the
 communications made known by ,legat1 it
 follows that 8the ideas concerning the 
reproduction of tones by means of       
electro-galvanism which were put forward
 some time since by ,philipp ,reis of   
,friedrichsdorf1 before the ,physical   
,society1 and the meeting of the ,free  
,german ,institute in                   
,frankfort-on-the-,main10 relate to     
similar arrangements4 8,what has        
hitherto been attained in the           
realisation of this project10 ,legat    
announces in his report1 and we extract 
therefrom only that part which gives an 

explanation of the disposition of the   
telegraphic apparatus1 with which it is 
said to be possible to produce the      
vibrations and the excitement of tones  
in any desired manner1 and by which the 
employment of electro-galvanism is said 
to make it possible 8to call into life  
at any given distance vibrations similar
 to the vibrations that have been       
produced1 and in this way to reproduce  
at any place the tones that have been   
originated at another place40  ,this    
apparatus consists of the tone-indicator
 7transmetteur7 and the tone-receiver   
7rcepteur74 ,the tone-indicator 7,fig4  
#cd1 p4 #aji7 consists of a conical     
tube1 a b1 having a length of about #ae 
cm41 a front aperture of about #aj cm41 
and a back aperture of about #d cm41 the
 choice of the material and the greater 
length of which is said to be           
indifferent1 while a greater width is   
said to be injurious2 the surface of the
 inner wall should be as smooth as      
possible4 ,the narrow back aperture of  

the tube is closed by a membrane1 o1 of 
collodion1 and upon the centre of the   
circular surface formed by this membrane
 rests the one end1 c1 of the lever1 c  
d1 the supporting-point of which1 e1    
being held by a support1 remains in     
connection with the metallic circuit4   
,this lever1 the arm1 c e1 of which must
 be considerably longer than c d1 should
 be as light as possible1 so that it can
 easily follow the movements of the     
membrane1 because an uncertain following
 of the lever1 c d1 will produce impure 
tones at the receiving station4 ,during 
the state of rest the contact1 d g1 is  
closed1 and a weak spring1 n1 keeps the 
lever in this state of rest4 ,upon the  
metallic support1 f1 which is in        
connection with one pole of the battery1
 there is a spring1 g1 with a contact   
corresponding to the contact of the     
lever1 c d1 at d1 the position of which 
is regulated by means of the screw1 h4  
,in order that the effect of the        
apparatus may not be weakened by the    

produced waves of air communicating     
themselves towards the back part1 a disc
 8of about #ej 787 cm4 diameter1 which  
rests fixedly upon the exterior wall of 
the tube10 is to be placed above the    
tube1 a b1 at right angles with its     
longitudinal axis4  ,illustration3 ,fig4
 #cd4  ,the tone-receiver consists of an
 electro-magnet1 m m1 which rests upon a
 resounding-board1 u w1 and the         
surrounding coils of which are connected
 with the metallic circuit and the      
earth4 ,opposite to the electro-magnet  
there stands an armature1 which is      
connected with a lever1 i1 as long as   
possible but light and broad1 and which 
lever together with the armature1 is    
fastened like a pendulum to the support 
k2 its movements are regulated by the   
screw l and the spring q4 8,in order to 
increase the effect of the apparatus1   
this tone-receiver may be placed in the 
one focus of an elliptically hollowed   
cavity of sufficient size1 while the ear
 of the person who listens to the       

reproduced sounds ought to be placed at 
the second focus of the cavity40 ,the   
action of the two apparatus1 the general
 manner of connection of which may be   
seen from the illustrations--at the one 
station being the tone-indicator1 at the
 other the tone-receiver--is the        
following3--,by speaking into1 singing1 
or conducting the tones of an instrument
 into the tube1 a b1 there is produced  
in the tone-indicator 7,fig4 #cd7 in    
consequence of the condensation and     
rarefaction of the enclosed column of   
air1 a motion of the membrane1 c1       
corresponding to these changes4 ,the    
lever1 c d1 follows the movements of the
 membrane1 and opens or closes the      
circuit according as there occurs a     
condensation or rarefaction of the      
enclosed air4 ,in consequence of these  
actions1 the electro-magnet1 m m 7,fig4 
#ac71 is correspondingly demagnetised or
 magnetised1 and the armature 7and the  
armature-lever7 belonging to it is set  
into vibrations similar to those of the 

membrane of the transmitting apparatus4 
,by means of the lever1 i1 connected    
with the armature1 the similar          
vibrations are transmitted to the       
surrounding air1 and these sounds thus  
produced finally reach the ear of the   
listener 7the sounding-board increasing 
the effect74 ,as regards the            
effectiveness of this apparatus1 the    
author remarks that while the similar   
number of the produced vibrations is    
reproduced by the receiver1 their       
original strength has not yet been      
obtained by it4 ,for this reason also   
small differences of vibration are      
difficult to hear1 and during the       
practical experiments hitherto made1    
chords1 melodies1 c41 could be1 it is   
true1 transmitted with astonishing 787  
fidelity1 while single words in reading1
 speaking1 c41 were less distinctly     
perceived4         99       99       99 
99       99      ,the rest of the       
article deals with the 8square-box0     
transmitter described in ,reis's        

,prospectus1 and adds nothing to     the
 information already published4  ,this  
is the last of the contemporary         
documents bearing upon the performance  
of ,reis's instruments4 ,from the       
prominent notice obtained at the time by
 the inventor1 it is clear that his     
invention was even then accorded an     
honourable place amongst the            
acknowledged conquests of science4 ,a   
critical examination of this body of    
evidence proves not only the substantial
 nature of ,reis's claim1 but that the  
claim was openly recognised and allowed 
by the best authorities of the time4    
,the thing was not done in a corner4    
,,footnotes3  #ae ,this was the number  
formerly accepted on the authority of   
,despretz as the minimum number of      
vibrations that could evoke the         
sensation of a tone in the human ear4   
,the limit now more usually recognized  
is that of ,helmholtz1 who assigns from 
thirty to forty double vibrations per   
second as the minimum4--,s4 ,p4 ,t4  #af

 ,the three plates or tables with which 
,reis accompanied his ,memoir1          
containing a variety of undulatory      
curves corresponding to various         
combinations of tones1 both of musical  
concords and of dissonant sounds1 are   
not reprinted in this book in their     
entirety4 ,table ,i4 contained three    
sets1 the first of which is reproduced  
by photo-lithography in reduced         
facsimile in ,fig4 #dg1 p4 #agc4 ,it was
 also reproduced by ,w4 von ,legat in   
his ,report from which ,plate ,i4 at end
 of this book is copied1 ,fig4 #a of    
that plate being the same as ,fig4 #a of
 ,reis's ,table ,i4 ,fig4 #b of ,plate  
#a1 was in like manner copied by ,legat 
from the first figure of ,reis's ,table 
,,ii41 and ,fig4 #c of ,plate ,i41 which
 represents the curves of a             
non-harmonious combination is the same  
as ,reis's ,table ,,iii41 the only      
difference being that in ,reis's ,table 
,,iii4 the irregular undulations of the 
resultant curve were emphasised by being

 labelled #8,dissonanz4'--,s4 ,p4 ,t4   
#ag ,this is true for speech-tones as   
well as for musical tones4 ,each kind of
 tone may be represented by its own     
characteristic curve4--,s4 ,p4 ,t4  #ah 
,this is the fundamental principle1 not 
only of the telephone1 but of the       
phonograph2 and it is wonderful with    
what clearness ,reis had grasped his    
principle in #ahfa4--,s4 ,p4 ,t4  #ai   
,that is1 at any single demagnetisation 
of the needle1 it vibrates and emits the
 same tone as if it had been struck or  
mechanically caused to vibrate          
longitudinally4--,s4 ,p4 ,t4  #bj ,this 
range was simply due to the degree of   
tension of the tympanum2 another        
tympanum differently stretched1 or of   
different proportions1 would have a     
different range according to            
circumstances4--,s4 ,p4 ,t4  #ba ,the   
so-called 8galvanic tone0 heard on      
opening or closing the circuit was      
well-known1 and ,wertheim had shown that
 this tone was1 for any given rod of    

iron1 identical with its 8longitudinal  
tone10 i4e4 the tone produced by        
striking it on the end so as to produce 
longitudinal vibrations4 ,but it was one
 of the most important discoveries in   
,reis's researches that such a rod could
 take up any tone in obedience to the   
vibrations forced upon it by periodic   
interruptions in the magnetising current
 in the spiral of any degree of rapidity
 within very wide limits4 ,the          
translator has had occasion to examine  
this point1 and has found iron1 steel1  
and cobalt wires varying from #d to #aj 
inches in length1 including some used by
 ,reis himself as receivers1 to be      
capable of taking up vibrations from as 
slow as #dj per second to the very      
shrillest whistle audible to human ears1
 or exceeding #cf1jjj per second4 ,it is
 sometimes also mistakenly supposed that
 such a wire can respond only to the    
vibrations of tones that are musical1   
not to those that are articulate1       
including both consonants and vowels4   

,this1 however1 is an entire mistake4   
,for1 using such a wire as a receiver   
7surrounded by its proper coil and      
mounted with an appropriate sounding    
board1 or1 better still1 tympanum71 in  
conjunction with a well-adjusted        
transmitter1 the articulation           
transmitted surpasses that obtainable   
with any of the ordinary magnetic       
receivers in distinctness1 though not in
 loudness4 ,this discovery of ,reis's is
 of the greatest importance1 especially 
as some who ought to know better have   
very unjustly denied the capability of  
this part of the apparatus to act as a  
telephone receiver for articulate       
sounds4--,s4 ,p4 ,t4  #bb ,this limit is
 a mistake of ,professor ,bttger's4 ,the
 longitudinal tone of an unstrained iron
 or steel wire #aj inches long would be 
a note about four octaves above the     
middle c of the piano2 whereas1 in fact1
 any note of the whole piano-gamut down 
to the lowest note1 can be reproduced by
 such a wire1 as stated in preceding    

footnote4--,s4 ,p4 ,t4  #bc ,professor  
,bttger had not to wait long for the    
fulfilment to a very large degree of    
this anticipation2 for within six months
 ,dingler's ,journal1 in which this     
article appeared1 contained ,legat's    
report on ,reis's instruments1 in which 
not only were various modifications in  
their construction made known1 but also 
the transmission of voice-tones1 not yet
 perfectly but with recognisable        
modulations and intonations1 was        
recorded4 ,reis had1 indeed1 succeeded  
nearly as well as this with his first   
instrument1 as his memoir of #ahfa      
shows4 ,see p4 #eh4  #bd ,compare #8,die
 ,geschichte und ,entwickelung des      
,fernsprechwesens1' a pamphlet issued   
officially in #ahhj from the ,imperial  
,german ,post-,office in ,berlin1 p4 #f4
  #be ,plate ,,viii4 of the original in 
,vol4 ,,ix4 of the ,zeitschrift4  #bf   
,plate ,,ix4 of the original ,memoir4   
#bg ,this word1 as the context and      
ending of the paragraph shows1 should   

have been spelled tones4 ,the letter1   
written in ,english by ,reis himself1 is
 wonderfully free from inaccuracies of  
composition2 the slip here noted being a
 most pardonable one since the plural of
 the ,german 8ton0 is 8tnen10 the very  
pronunciation of which would account for
 the confusion in the mind of one       
unaccustomed to write in ,english4 ,so  
far as is known1 this is the only piece 
of ,english composition ever attempted  
by ,reis4--,s4 ,p4 ,t4  #bh ,reis here  
sketched a figure identical in all its  
parts with that which a fortnight later 
was issued in his #8,prospectus4' ,his  
sketch is reproduced in facsimile in    
,fig4 #bh4  #bi ,this was the little    
auxiliary signalling apparatus at the   
side of the box1 placed there for the   
same reasons as the auxiliary call-bell 
attached to modern telephones4  #cj     
,this word is underscored in ,reis's    
original letter4  #ca ,compare ,bttger  
,polyt4 ,notizbl4 #ahfc1 p4 #ha1 the    
notice translated at p4 #fa             

preceding4--,s4 ,p4 ,t4  #cb ,this      
rather obscure passage refers to the    
call-key or communicator fixed to the   
side of the instruments1 and which as   
the inventor explains in his ,prospectus
 7see p4 #hg71 to be intended1 like the 
call-bell or communicator of modern     
telephones1 as a means of sending       
signals to the speaker1 and which1 as   
the ,prospectus says1 can also be       
used--as any call-bell can--for         
telegraphing words by a pre-arranged    
code of signals4--,s4 ,p4 ,t4  #cc ,fig4
 #cj of this book4  #cd ,references4    
,telephon von ,reis im ,jahresbericht   
des physikalischen ,vereins zu          
,frankfurt-a4-,m4 fr #ahfj-ahfa1 pag4   
#eg bis #fd4 ,mller-,pouillet1 ,physik1 
#ahfc1 #f4 ,auflage1 ,,ii pag4 #ceb1    
,fig4 #cbe4 ,berl4 ,ber4 fr #ahfa1 xvii4
 pag4 #aga bis #agc4 ,der               
,musiktelegraph in der 8,gartenlaube0   
#ahfc1 ,nr4 #ea1 pag4 #hjg bis #iji4    
,aus der ,natur #ahfb1 xxi4 pag4 #dgj   
bis #dhd2 ,knig's ,catalog1 #ahfe1 pag4 

#e4  #ce ,this part of the apparatus is 
in fact a 8call10 serving precisely the 
same function as the call-bell attached 
to ordinary telephones1 by which the    
subscriber can be 8called up0 to listen 
to the instrument4 ,it is not without   
importance to observe that this function
 was perfectly well-known at the time2  
for it was gravely argued during a      
former telephone law-suit in ,england   
that the presence of this 8signal-call0 
at the side of the ,reis ,transmitter   
was a proof that it was intended to     
transmit singing only and not speech1 or
 8else there would not have been that   
little ,morse-instrument at the side by 
which to talk06 ,this suggestion is1    
however1 self-evidently absurd1 because 
if this had been the case the little    
electromagnetic ,morse telegraph would  
have been fixed1 not on the side of the 
transmitter but on that of the receiver4
 ,reis himself explains the use of the  
8call0 7see p4 #hg7 in his              
8,prospectus40--,s4 ,p4 ,t4  #cf        

,professor ,pisko seems to have got hold
 of an unusually unfortunate specimen of
 the instrument if he could make it     
neither speak nor sing4 ,his transmitter
 must have been in exceedingly bad      
condition to fail so completely4  #cg   
,this error has been copied by ,count du
 ,moncel1 along with the other defects  
of the article1 into the fifth volume of
 his #8,applications of ,electricity1'  
published in #ahgh4 ,it is rather       
amusing now to read1 at p4 #ajf1 of ,du 
,moncel's treatise that 8,heisler0 7sic7
 8pretends0 that the telephone of       
8,reuss10 which 8appears0 to have been  
invented 8anterior to the year #ahff10  
was capable of transmitting vocal       
melodies6 ,count du ,moncel1 though he  
has since posed as an authority on the  
telephone1 did not in #ahgh shine in    
that capacity1 for on the very same page
 of the ,count's book may be found the  
following astounding sentiment3--8,if it
 is true1 as ,sir ,w4 ,thomson has      
assured us1 that at the ,philadelphia   

,exhibition of #ahgf there was a        
telegraphic system transmitting words1  
we may recognize10 c4 ,count du ,moncel 
has since found out that it is true that
 there was a ,telephone in ,philadelphia
 in #ahgf3 perhaps he will next discover
 that 8,reuss0 did1 8anterior to the    
year #ahff10 actually 8appear0 to       
transmit not only what 8,heisler0       
8pretends0 he did1 but that he also     
transmitted spoken words4--,s4 ,p4 ,t4  
#ch ,ueber ,fortpflanzung der ,tne auf  
wilkhrlich weite ,entfernungen1 mit     
,hlfe der ,elektricitt 7,telephonie74   
,polyt4 ,journ4 clxviii4 #ahe2 aus      
,bttger's ,notizbl4 #ahfc1 ,nr4 #f4 ,see
 translation on page #fa4     ,,chapter 
,v4  ,,testimony ,,of ,,contemporary    
,,witnesses4    #a4 ,professor ,g4      
,quincke4   #b4 ,professor ,c4 ,bohn4   
#c4 ,herr ,lon ,garnier4   #d4 ,ernest  
,horkheimer1 ,esq4   #e4 ,dr4 ,r4       
,messel1 ,f4,c4,s4   #f4 ,herr ,heinrich
 ,holt4   #g4 ,herr ,heinrich ,f4       
,peter4   #h4 ,mr4 ,stephen ,m4 ,yeates4

   #i4 ,dr4 ,william ,frazer4           
,professor ,g4 ,quincke1  ,professor of 
,physics in the ,university of          
,heidelberg4      ,professor ,quincke1  
whose name is so well known in          
connection     with his researches in   
molecular physics and in many problems  
of the highest interest to those        
acquainted with electrical     science1 
was one of those present at the         
,naturforscher     ,versammlung held at 
,giessen in #ahfd1 where ,reis's        
,telephone     was publicly exhibited by
 its inventor1 see page #ic1 ante4      
,his testimony1 coming from so high     
authority1 is therefore of              
exceptional value4  8,dear ,sir1  8,i   
was present at the ,assembly of the     
,german ,naturalists' ,association      
7,naturforscher ,versammlung7 held in   
the year #ahfd in ,giessen1 when ,mr4   
,philipp ,reis1 at that time teacher in 
the ,garnier ,institute at              
,friedrichsdorf1 near                   
,frankfort-on-the-,main1 showed and     

explained to the assembly the ,telephone
 which he had invented4  8,i witnessed  
the performance of the instruments1 and1
 with the assistance of the late        
,professor ,bttger1 heard them for      
myself4  8,the apparatus used consisted 
of two parts--a transmitter and a       
receiver4 ,the transmitter was a box1   
one side of which was furnished with a  
tube into which the speaking was to be  
done4 ,at the top or the side of the box
 there was a circular opening1 covered  
by a tympanum of membrane1 upon which   
was fastened a piece of platinum4 ,this 
piece of platinum was in communication  
with one pole of the galvanic battery4  
,over the membrane1 resting upon the    
platinum1 and in contact with it1 was a 
piece of metal furnished with a platinum
 point1 also in connection with one pole
 of the battery4  8,the receiver        
consisted of a common knitting needle of
 steel1 surrounded by a magnetising coil
 of insulated wire1 which also formed a 
part of the circuit1 the whole resting  

on a resonant box4  8,i listened at the 
latter part of the apparatus1 and heard 
distinctly both singing and talking4 ,i 
distinctly remember having heard the    
words of the ,german poem1 #8,ach6 du   
lieber ,augustin1 ,alles ist hin6'0 c4  
8,the members of the ,association were  
astonished and delighted1 and heartily  
congratulated ,mr4 ,reis upon the       
success of his researches in ,telephony4
    7,signed7      8,dr4 ,g4 ,quincke1  
,professor4    8,heidelberg1 #ajth      
,march1 #ahhc40         99       99     
99       99       99                    
,professor ,c4 ,bohn4      ,professor   
,c4 ,bohn1 of ,aschaffenburg1 was       
formerly ,secretary     to the ,german  
8,naturforscher0 ,association1 was also 
,secretary     to the ,physical ,section
 of this ,society 7vide p4 #ic74 ,in    
that     capacity he had every          
opportunity of knowing what was going on
     in science2 hence the following    
7translated7 letter1 addressed     to   
the author of this book1 is of peculiar 

value4  8,most esteemed ,sir1  8,i      
willingly answer1 as well as ,i am able 
to do so1 the questions put by you4 ,in 
order to explain that my recollections  
may not have all the sharpness that     
might be wished1 ,i make the following  
prefatory statement4 ,i have1 about     
#ahfc1 held numerous conferences with   
,mr4 ,reis and with my deceased         
colleague1 ,professor ,h4 ,buff1 of     
,giessen1 and on these occasions have   
argued the question how it is that the  
transmission of thoughts to a distance  
by the sensation of the ear has a       
distinctly less value than transmission 
by that which is written4444  8,and now 
to your questions4 ,i was not at        
,stettin in #ahfc4 ,at the experiments  
at ,giessen in the ,naturforscher       
,assembly on #bast ,september1 #ahfd1 ,i
 was present2 the short notice about    
them in the journal 7#8,tagesblatt'7 is 
from my pen4 ,i was ,secretary of the   
,assembly and of the ,physical ,section4
 ,i remember1 however1 almost absolutely

 nothing about these experiments4 ,but  
,i remember well that                   
previously--therefore probably as early 
as #ahfc--;having jointly made the      
experiments with ,reis's telephone in   
,buff's house in ,giessen4444 ,i have   
myself1 as speaker and as hearer1 at    
least twice1 in the presence of ,reis1  
made the experiments4  8,it was known to
 me 7in #ahfc-fd7 that ,reis intended to
 transmit words1 and certainly spoken   
words as well as those sung4 ,my        
interest in the matter was1 however1 a  
purely scientific one1 not directed to  
the application as a means of profit4   
8,with great attention the sense of the 
words was understood4 ,i have understood
 such myself1 without knowing previously
 what would be the nature of the        
communication through the telephone4    
,words sung1 especially well accentuated
 and peculiarly intoned1 were somewhat  
better 7or rather less incompletely7    
understood than those spoken in the     
ordinary manner4 ,there was indeed a boy

 7son of ,privy-,councillor ,ihering1   
now of ,gttingen1 then of ,giessen71 who
 was known as specially accomplished as 
a speaker4 ,he had a rather harsh       
,north-,german dialect1 and after the   
first experiments hit on the right way  
to speak best1 essential for            
understanding4 ,i myself did not        
understand ,professor ,buff through the 
telephone4 ,whether the speaker could be
 recognized by his voice ,i doubt4 ,we  
knew beforehand each time who speaks4   
,yet ,i remember that a girl could be   
distinguished from that boy by the      
voice4  8,the ear was at times laid upon
 the box of the apparatus1 also upon the
 table which supported the telephone4   
,then it was attempted to hear at a     
distance1 with the ear in the air2 in   
this respect1 when singing1 with good   
result4 ,at times the lid was taken off1
 or the same was connected more or less 
tightly or loosely with the lower part4 
,the result of these changes ,i can no  
longer give with distinctness4444       

8,should you desire further information1
 ,i am ready to give you it according to
 my best knowledge4                     
8,hochachtungsvoll ergebenster1   8,dr4 
,c4 ,bohn4    8,aschaffenburg1   8#ajth 
,september1 #ahhb40         99       99 
99       99       99                    
,lon ,garnier4      ,herr ,lon ,garnier1
 ,proprietor and ,principal of the      
,garnier     ,institute at              
,friedrichsdorf1 is the son of the late 
,burgomaster     ,garnier1 who founded  
the establishment1 and who1 as          
previously     narrated1 encouraged     
,philipp ,reis in his work and offered  
him     the post of teacher of ,natural 
,science4 ,herr ,lon ,garnier owns      
the small collection of instruments     
which ,reis left behind1 and     which  
are preserved in the ,physical ,cabinet 
attached to the     ,institute1 where   
also may be seen the gravitation        
machine--an     ingenious combination of
 the principles of ,atwood's and        
,morin's     machines--and the automatic

 weather-recorder invented by ,reis1    
both1 however1 very greatly out of      
repair4 ,herr ,garnier has     furnished
 to a friend the following particulars  
about ,reis and     his invention4  8,i 
knew ,philipp ,reis1 now deceased1      
during his life-time4444 ,about the year
 #ahei1 he was employed by my father1   
then proprietor and director of the     
,friedrichsdorf ,garnier ,institute1 as 
teacher of mathematics and natural      
sciences4 ,he employed his hours of     
leisure in experimenting for himself in 
a house occupied by himself1 and in     
which he had established a physical     
laboratory with a view mainly of        
realizing an idea which he had conceived
 sometime before of transmitting the    
human voice over divers metallic        
conductors by means of a galvanic       
current4444 ,i remember especially1     
that1 standing at the end of the wire or
 conductor1 ,mr4 ,reis speaking through 
his instrument1 ,i distinctly heard the 
words3 #8,guten ,morgen1 ,herr ,fischer'

 7,good morning1 ,mr4 ,fischer72 #8,ich 
komme gleich' 7,i am coming directly72  
#8,passe auf6' 7,pay attention672 #8,wie
 viel ,uhr ist es8' 7,what o'clock is   
it872 #8,wie heisst du8' 7,what's your  
name87 ,we often spoke for an hour at a 
time4 ,the distance was about #aej feet4
    8,lon ,garnier40         99       99
       99       99       99             
,ernest ,horkheimer1 ,esq4              
8,manchester1 ,dec4 #b1 #ahhb4          
8,professor ,s4 ,p4 ,thompson1          
8,dear ,sir1  8,in reply to your favour 
of #cast instant1 ,i shall be very happy
 to give you all the information ,i can 
with respect to the telephonic          
experiments of my late friend and       
teacher ,mr4 ,philipp ,reis4 ,i would   
express my gratification at finding that
 you are trying to put my old teacher's 
claims on their just basis4 ,i have     
always felt that in this race for       
telephonic fame1 his claims have been   
very coolly put aside or ignored4 ,that 
he did invent the ,telephone there is   

not the remotest doubt4 ,i was1 ,i      
think1 a great favourite of his2 and at 
the time his assumption was that ,i was 
destined for a scientific career1 either
 as a physicist or a chemist2 and ,i    
believe that he said more to me about   
the telephone than to any one2 and ,i   
assisted him in most of his experiments 
prior to the spring of #ahfb4  8,philipp
 ,reis intended to transmit speech by   
his telephone--this was his chief aim2  
the transmitting of musical tones being 
only an after-thought1 worked out for   
the convenience of public exhibition    
7which took place at the ,physical      
,society at ,frankfort-on-the-,main74 ,i
 myself spent considerable time with him
 in transmitting words through the      
instruments4 ,we never 7in my time7 got 
the length of transmitting complete     
sentences successfully1 but certain     
words1 such as #8,wer da8' #8gewiss1'   
#8warm1' #8kalt1' were undoubtedly      
transmitted without previous            
arrangement4 ,i believe ,reis made      

similar experiments with his            
brother-in-law4  ,illustration3 ,fig4   
#ce4  ,illustration3 ,fig4 #cf4  8,i    
recollect the instrument in the shape of
 the human ear very well3 it was ,reis's
 earliest form of transmitter4 ,the     
transmitter underwent a great many      
changes1 even during my time4 ,the form 
you sketch 7,fig4 #i1 p4 #bj7 was almost
 the oldest one1 and was soon superseded
 by the funnel-shape 7,fig4 #ce74 ,the  
back was always closed by a tympanum of 
bladder1 and many a hundred bladders    
were stretched1 torn1 and discarded     
during his experiments4 ,i recollect him
 stating to me that he thought a very   
thin metal tympanum would eventually    
become the proper thing1 and one was    
actually tried1 coated over on one side 
with shellac1 and on the other likewise1
 except at the point of contact 7,fig4  
#cf74 ,i believe it was made of very    
thin brass1 but at the time the         
experiments were not satisfactory4 ,talc
 was also tried1 but without success1   

the platinum contacts being in all cases
 preserved4  8,i remember very well     
indeed the receiver with a steel wire1  
surrounded by silk-covered copper wire4 
,the first one was placed on an empty   
cigar-box1 arranged thus3--             
,illustration3 ,fig4 #cg4  8,the wire   
was a knitting-needle and the copper    
wire was spooled on a paper case4       
,illustration  8,the spiral was         
supported by a little block of wood1 so 
as to allow the knitting-needle not to  
touch it anywhere4 ,later on a smaller  
cigar-box was invented as a cover--thus2
 7,fig4 #ch7--;having two holes cut into
 it like the f-holes in a violin4       
,illustration3 ,fig4 #ch4  8,the        
practice was to place the ear close to  
the receiver1 more particularly so when 
the transmission of words was attempted4
  8,the spiral was1 during the early    
experiments1 placed on a violin--in     
fact1 a violin which ,i now possess was 
sometimes used1 as it was of a peculiar 
shape1 which ,reis thought would help   

the power of tone4  8,i have already    
enumerated some of the words which were 
transmitted1 but there were many more2  
on one occasion a song1 known in this   
country as #8,the ,young ,recruit' 7,wer
 will unter die ,soldaten7 was          
transmitted1 the air and many of the    
words being clearly intelligible4  8,i  
do not recollect seeing the receiver    
shewn in the woodcut 7,fig4 #ba71 but   
,reis often said that he would make such
 a one1 although the sketch he made for 
me then differed in some details from   
your woodcut4 ,reis intended to keep me 
fully informed of all he could achieve1 
but1 immediately after leaving his      
tuition1 ,i fell ill1 and was laid up   
for a very long time4 ,shortly          
afterwards ,i left for ,england1 and    
then he died1 and ,i never saw him      
again4 ,the electromagnet form was      
certainly strongly in his mind at the   
time we parted1 and he drew many        
alternative suggestions on paper1 which 
have probably been destroyed2 but the   

electromagnets in all of them were      
placed upright1 sometimes attached to   
the top of a hollow box1 and sometimes  
to the bottom of a box arranged thus    
7,figs4 #ci1 #dj72 but1 to my           
recollection1 they never got beyond the 
stage of drawings1 whatever he may have 
done after he and ,i parted company4    
,illustration3 ,fig4 #ci4               
,illustration3 ,fig4 #dj4  8,in         
conclusion1 ,i beg to send you herewith 
a photograph of ,philipp ,reis 7see     
,fig4 #ab1 p4 #bc71 holding in his hand 
the instrument ,i helped him to make1   
and which photograph he took of himself1
 exposing the camera by a pneumatic     
arrangement of his own1 and which formed
 part of a little machine which he      
concocted for turning over the leaves of
 music-books4  8,the instrument used by 
,reis at the ,physical ,society may have
 been the square block form3 ,i believe 
that this cone-form was not quite       
completed then4 ,at the ,saalbau        
7,hochstift71 however1 ,i am sure the   

instrument shown in my photograph was   
employed2 not with a tin cone1 but a    
wooden one4 ,i send you herewith a      
sketch of what ,i remember that         
instrument to have been4 ,i am not      
absolutely certain whether in the       
instrument there was not an             
electromagnet introduced1 but ,i think  
not4 ,my recollection leads me to       
suppose that the electromagnet          
arrangement was added subsequently4     
,thinking it over again1 ,i should1     
however1 think that the instrument in   
the photo must have been one in which a 
bent lever was placed behind the        
tympanum1 and that the rectangular patch
 seen above was a wooden casing to      
shelter the parts4 ,there may be some   
confusion in my mind as to the position 
of this box1 but ,i somehow think the   
rectangular patch is only part of a     
larger box which is not apparent in the 
photograph4 ,i have no idea where the   
original instrument is now1 but ,i      
should hardly think it could be in      

existence4 ,reis used to take some      
instruments to pieces to utilise parts  
in subsequent experiments1 and ,i       
recollect how keen he used to be about  
the bits of platinum1 which he always   
described as #8ein sehr kostbares       
,metall4' ,what always was a great      
puzzle was the attaching of the platinum
 plate to the membrane1 which he did    
generally by sealing-wax1 saying at the 
same time3 #8,es ist nicht recht so1    
aber ich weiss nicht wie es anders      
gemacht werden kann6'    8,believe me1  
my dear ,sir1 yours truly1              
8,ernest ,horkheimer40         99       
99       99       99       99           
,dr4 ,rudolph ,messel4      ,the        
following letter from ,dr4 ,rudolph     
,messel1 ,f4,c4,s41     addressed to the
 author of this book1 in reply to       
enquiries     concerning ,reis and his  
inventions1 speaks for itself4 ,dr4     
,messel's letter differs from almost all
 the others here     reprinted in having
 been specially written for the purpose 

of     being inserted in this           
volume4--,s4 ,p4 ,t4                    
8#cf1 ,mark ,lane1 ,london1 #cjth       
,april1 #ahhc4   8,dear ,professor      
,thompson1  8,at last ,i find a moment  
to comply with your request4 ,my        
knowledge of ,philipp ,reis dates from  
#ahfj1 when ,i was a pupil at ,professor
 ,garnier's ,school at ,friedrichsdorf1 
of which school ,reis was one of the    
undermasters4 ,reis1 naturally          
communicative1 was very fond of talking 
to us boys about his scientific         
researches4 ,and it was on the occasion 
of one of our daily walks together that 
he told me how1 when an apprentice at   
,beyerbach's 7colour-manufacturer71 in  
,frankfurt-a4-,m41 he was one day       
amusing himself in watching the         
behaviour of a small magnetic compass4  
,this compass he found1 on being placed 
near to the base of various iron columns
 in the warehouse1 was attracted4       
,disturbed by the entrance of one of the
 principals1 who imagined that ,reis    

ought to employ his time more           
profitably1 he withdrew to a stage where
 he could pursue his experiments        
unobserved4 ,much to his surprise1 he   
now found that the pole attracted by the
 base was repulsed at the top of the    
columns1 which observation led him to   
examine other pieces of iron on the     
premises4 ,he next built up a column    
with all the weights in the warehouse1  
and having verified his previous        
observations1 he communicated what he   
believed to be his first and great      
discovery either to ,professor ,bttger  
or to ,dr4 ,oppel4 ,great was his       
disappointment to learn at this         
interview that he had unwittingly       
stumbled across a well-known physical   
fact3 but his disappointment stimulated 
in him the desire to learn more of the  
marvellous laws and mysteries of nature4
 ,that ,reis evoked a similar desire in 
those with whom he came in contact need 
not cause surprise1 and thus it came    
about that ,horkheimer1 ,kster1         

,schmidt1 and myself1 soon enjoyed the  
privilege of private instructions in    
physics1 and of being permitted to      
witness his telephonic experiments      
amongst others4 ,i was1 however1 very   
young1 and am sorry that much that ,i   
then saw and heard has been forgotten1  
,reis insisted that his transmitter     
7which he called the #8ear'7 should be  
capable of performing the functions of  
that organ1 and he never tired of       
drawing diagrams of the numerous curves 
of sounds to explain how necessary it   
was that the transmitter should follow  
these curves before perfect speaking    
could be attained1 and which kind of    
curves the instrument so far could      
reproduce4 ,numerous experiments were   
made with transmitters1 exaggerating or 
diminishing the various component parts 
of the ear4 ,wooden and metallic        
apparatus1 rough and smooth1 were       
constructed in order to find out what   
was essential1 and what was not4        
,illustration3 ,fig4 #da4  8,one form of

 transmitter was at that time           
constructed which ,i miss amongst the   
various woodcuts you were good enough to
 send me1 and one which ,reis based     
great hopes upon4 ,the instrument was   
very rough1 however1 consisting of a    
wooden bung of a beer-barrel 7which ,i  
had hollowed out for an earlier         
telephone--it was not turned inside like
 others71 and this was closed with a    
membrane4 ,the favourite #8,hmmerchen'  
was replaced by a straight wire1 fixed  
in the usual way with sealing-wax1 and  
the apparatus stood within a sort of    
tripod1 membrane downwards1 the pin just
 touching the surface of a drop of      
mercury contained in a small cup forming
 one of the terminals of the circuit4   
,the apparatus started off with splendid
 results1 but may probably have been    
abandoned on account of its great       
uncertainty1 thus sharing the fate of   
other of his earlier instruments4 ,in my
 belief it is to these mechanical       
imperfections1 due principally to the   

want of sufficient means at his command1
 that we must look to find the reason   
why ,reis's telephone did not come to an
 earlier fame4 ,thus ,reis informed me  
that he intended to exhibit it once at  
some scientific meeting at ,cassel1 but 
notwithstanding a perfect rehearsal it  
was impossible to show the working to   
the audience2 the failure was attributed
 by ,reis to atmospheric influence      
7stretching of the diaphragm71 and he   
felt much grieved at having lost his    
chance4 ,to make matters worse1 the     
early transmitters had no adjusting     
screws1 and the contact was only        
regulated by a piece of bent wire1 and  
the #8hammer' was fixed to the membrane4
 ,philipp ,schmidt should recollect what
 ,i state1 as many experiments were made
 when only he1 ,reis1 and myself were   
present1 he being at one and ,i at the  
other end of the apparatus4 ,the wire   
was stretched from ,reis's house1 in the
 main road1 through the yard to a       
hayloft1 near the garden or field4 ,we  

transmitted musical sounds 7organ1 c471 
singing popular songs 7#8,wer will unter
 die ,soldaten1' #8,ich hatt' einen     
,kameraden1' c47 and speaking1 or1 more 
correctly1 reading4 ,we had a book1 and 
were to find out what part of the page  
the reader was just transmitting4 ,we   
frequently used a sort of #8,exercier   
,reglement1' a soldiers' instruction    
book1 or something of that sort4 ,i have
 a distinct recollection of             
electromagnetic receivers being used1   
but not of their construction1 except   
that the use of one of them was         
accompanied by a rattling and disturbing
 noise4 ,the knitting-needle put in the 
f of a violin was1 however1 the more    
favoured receiver1 but at this time1 in 
,reis's mind1 all seemed to hinge on the
 electromagnet1 as it had before1 and1  
,i dare say1 did again afterwards on the
 transmitter4 ,i left ,friedrichsdorf in
 '#fb1 and rarely saw ,reis after that1 
except a few times at ,mechanicus       
,albert's 7who made some of his         

apparatus71 and at ,professor ,bttger's1
 to whom he introduced me4 ,reis        
attended ,professor ,bttger's lectures  
at the ,physikalischer ,verein1 when in 
,frankfort1 prior to his settling down  
at ,friedrichsdorf2 but ,i do not know  
that any particularly intimate relation 
existed between them4 ,dr4 ,poppe1      
director of the ,gewerbeschule 7,trade  
,school71 now deceased1 on whose advice 
he chiefly relied1 was then one of his  
more intimate friends1 ,professor ,oppel
 being occasionally consulted about more
 intricate mathematical problems4 ,of   
the #8meteorological recorder' invented 
by ,reis ,i recollect but its existence1
 but nothing at all of a #8fall-machine'
 of his construction4 ,the velocipede ,i
 only recollect1 because he lent it to  
me for a masquerade4 ,at his suggestion 
we altered it into a large musical-box1 
putting ,herr ,peter inside1 who played 
on the clarinet when ,i turned a handle4
 ,dr4 ,kellner states that its chief    
merit consisted in being able to go     

downhill1 and that poor ,reis came back 
7uphill7 puffing away1 dragging his     
velocipede behind him4 ,kellner no doubt
 could give valuable information on     
,reis's theory of electricity1 his      
conviction that there was only one kind 
of electricity1 his acoustic researches1
 and those on radiation of electricity1 
his galvanoplastic experiments1 c41 c4  
8,in personal appearance ,reis was not  
very refined1 but he had a striking     
countenance and a very powerful look4   
,though occasionally very irritable1    
especially with dunces1 he was always   
warm-hearted1 and showed great kindness 
to those who cared to understand him4   
,reis's views of the telephone may1 of  
course1 have changed after ,i knew him1 
and looking at his later instruments1   
one of which ,i possess1 ,i cannot help 
thinking they did2 at any rate1 ,i do   
not see how1 in these instruments1 the  
current got interrupted at all1 and the 
instruments must have acted like        
microphones1 whether known or unknown to

 him4 ,when listening to the instrument 
he frequently said to me1 8,you         
understand it is a #8molekular          
,bewegung' 7molecular motion74  8,i am  
sorry that1 owing to the lapse of time1 
,i am unable to throw more light on     
,reis's original labours in a field of  
physical science which promised so much 
for the future2 but insufficient as are 
my recollections1 they may not be       
without public interest1 and at any rate
 ,i am glad of this opportunity of      
offering my humble tribute of regard and
 affection to the memory of my old      
teacher and friend4    8,yours truly1   
8,rudolph ,messel40         99       99 
99       99       99                    
,heinrich ,hold4      ,herr ,hold1      
formerly a colleague of ,philipp ,reis  
in the ,garnier     ,institute at       
,friedrichsdorf1 but now proprietor of a
 leather     factory in the same place1 
was teacher of mathematics4 ,he was     
in his younger days a fellow-student of 
,professor ,tyndall     at ,halle1 and  

was well acquainted with physical       
science in     general4 ,his intimate   
connection with ,reis1 and close        
knowledge     of ,reis's work1 enable   
him to confirm the testimony of others  
in many important points4    ,to        
,professor ,s4 ,p4 ,thompson in         
,bristol4    8,esteemed ,sir1  8,i have 
much pleasure in furnishing you with the
 following particulars concerning my    
late colleague ,philipp ,reis1 the      
inventor of the ,telephone4 ,he was     
himself educated at the ,garnier's      
,institute in ,friedrichsdorf where ,i  
was also teacher of mathematics4 ,i knew
 him very well during his life-time4    
,among his numerous original researches1
 his invention of the telephone was the 
principal one4 ,his idea was to         
reproduce the tones both of musical     
instruments and of the human voice by   
means of electricity1 using a covered   
wire wound in a spiral round an iron    
core1 the same being placed upon a      
resonant box4 ,in this he succeeded1    

inasmuch as with an apparatus1 which he 
showed to the ,physikalischer ,verein in
 ,frankfurt-a4-,m41 in the year #ahfa1  
he reproduced music1 singing1 single    
words and short sentences2 all of which 
were distinctly audible over a short    
distance from his dwelling-house through
 the yard to the barn4 ,every voice was 
not equally well adapted for speaking   
into the apparatus1 neither could every 
ear understand the telephone language   
equally well4 ,words spoken slowly1 and 
singing1 both in a middle tone1 were the
 most easy to reproduce4 ,i helped ,mr4 
,reis to make many of his experiments1  
and have spoken and sung into the       
telephone1 the same being generally     
heard and understood4 ,i have also heard
 and understood short sentences when ,i 
was standing at the end station4 ,a     
brother-in-law of ,mr4 ,reis1 who is now
 paymaster in the ,imperial ,navy at    
,wilhelmshavn1 generally conducted the  
speaking and singing in the telephone4  
8,heinrich ,hold40         99       99  

99       99       99                    
,heinrich ,friedrich ,peter4      ,herr 
,peter is still ,music-teacher in the   
,garnier ,institute1     and has a vivid
 recollection of his former colleague   
,philipp     ,reis1 and of the          
experiments with the telephone4         
8,dear ,sir1  8,the following           
particulars concerning ,reis's          
,telephone ,i have several times        
narrated4 ,i was teacher of music in    
,garnier's ,institute at the time when  
,mr4 ,reis invented the telephone1 in   
the year #ahfa4 ,i was much interested  
in his experiments1 and visited him     
daily1 giving him help and making       
suggestions4 ,his first idea was to     
imitate the construction of the human   
ear4 ,he constructed a funnel-shaped    
instrument1 the back of which was       
covered with a skin of isinglass1 upon  
which was fastened a piece of platinum1 
against which rested a platinum point4  
,as receiver of the electric current he 
used a common knitting-needle1          

surrounded by a coil of insulated green 
wire1 which was at first merely laid on 
a table4 ,at first the tones were very  
much interfered with by a buzzing noise4
 ,at my suggestion he placed the spiral 
upon my violin as a resonant-box2       
whereupon the tones were perfectly      
understood1 though still accompanied by 
the buzzing noise4 ,he continued        
experimenting1 trying various kinds of  
membranes1 and made continual           
improvements in the apparatus4 ,i was   
present and assisted at the experiments 
at ,frankfort-on-the-,main1 on the #bfth
 of ,october1 #ahfa2 and after the      
meeting broke-up1 ,i saw the members of 
the ,society as they came and           
congratulated ,mr4 ,reis on the success 
of his experiments4 ,i played upon the  
,english horn1 and ,philipp ,schmidt    
sang4 ,the singing was heard much better
 than the playing4 ,at an experiment    
which we made at ,friedrichsdorf1 in the
 presence of ,hofrath ,dr4 ,mller1      
,apothecary ,mller1 and ,professor ,dr4 

,schenk1 formerly ,director of          
,garnier's ,institute1 an incident      
occurred which will interest you4       
,singing was at first tried2 and        
afterwards his brother-in-law1 ,philipp 
,schmidt1 read long sentences from      
,spiess's #8,turnbuch' 7,book of        
,gymnastics71 which sentences ,philipp  
,reis1 who was listening1 understood    
perfectly1 and repeated to us4 ,i said  
to him1 #8,philipp1 you know that whole 
book by heart2' and ,i was unwilling to 
believe that his experiment could be so 
successful unless he would repeat for me
 the sentences which ,i would give him4 
,so ,i then went up into the room where 
stood the telephone1 and purposely      
uttered some nonsensical sentences1 for 
instance3 #8,die ,sonne ist von ,kupfer'
 7,the sun is made of copper71 which    
,reis understood as1 #8,die ,sonne ist  
von ,zucker' 7,the sun is made of       
sugar72 #8,das ,pferd frisst keinen     
,gurkensalat' 7,the horse eats no       
cucumber-salad72 which ,reis understood 

as #8,das ,pferd frisst4444' 7,the horse
 eats 44474 ,this was the last of these 
experiments which we tried4 ,those who  
were present were very greatly          
astonished1 and were convinced that     
,reis's invention had opened out a great
 future4    8,h4 ,f4 ,peter1            
,musiklehrer40         99       99      
99       99       99                    
,stephen ,mitchell ,yeates1 ,esq4       
,illustration3 ,fig4 #db4      ,mr4     
,yeates is a well-known instrument-maker
 in the city of     ,dublin1 and in     
#ahfe1 purchased from ,mr4 ,w4 ,ladd1 of
 ,london1     a ,reis's ,telephone of   
the form shown in ,reis's ,prospectus   
7,fig4 #bi74 ,mr4 ,yeates1 after a few  
experiments1 rejected the               
knitting-kneedle receiver1 and replaced 
it by the instrument     shown in ,fig4 
#db1 which consisted of an electromagnet
 mounted     above a sound-box1 having a
 vibrating armature furnished     with  
an adjusting screw to regulate its      
distance from the     poles of the      

electromagnet4 ,this instrument worked1 
even when     the armature was in       
absolute contact with both poles of the 
electromagnet1 and as the magnet did not
 during the experiments     lose its    
hold on the armature1 it was clear that 
the effects     were due to alterations 
in the intensity of the magnetism of    
the magnet4 ,the apparatus was shewn at 
the ,november meeting     of the ,dublin
 ,philosophical ,society1 when singing  
and words     were transmitted4 ,with a 
careful adjustment it was possible      
to distinguish all the quality of the   
note sung into the     transmitter and  
to distinguish the difference between   
any     two voices4 ,the instruments    
were then sold to the late ,rev4        
,mr4 ,kernan1 who was then ,professor of
 ,physics in ,clongowes     ,wood       
,college4 ,the following recent letter  
from ,mr4 ,yeates     corroborates the  
above facts4                            
8#b1 ,grafton ,street1 ,dublin1         
8,march #ast1 #ahhc4    8,dear ,sir1    

8,there are several residing at present 
in ,dublin who were present at my       
telephonic experiments in #ahfe2 three  
of them1 namely1 ,dr4 ,w4 ,frazer1 ,mr4 
,a4 ,m4 ,vereker1 and ,mr4 ,e4 ,c4      
,tuke1 took an active part in the       
experiments1 and remember all the       
circumstances connected with them4 ,the 
voice of each was instantly recognised  
in the receiver2 in fact1 this point    
attracted special attention at the time4
  8,i had no knowledge at that time that
 ,reis had used an electromagnetic      
receiver1 nor did ,i know that ,reis was
 the inventor of the instrument which ,i
 got from ,mr4 ,ladd4  8,the original   
instrument made by me is1 ,i believe1   
still in the ,museum at ,clongowes ,wood
 ,college4 ,the ,president kindly lent  
it to me some time ago1 and ,i returned 
it to him again after showing it to     
,professor ,barrett4 ,i have a cut of   
this receiver1 which ,i will send to you
 if it will be of any use to you4       
8,yours truly1     8,s4 ,m4 ,yeates40   

99       99       99       99       99  
,william ,frazer1 ,esq41 ,m4 ,d41       
8#bj1 ,harcourt ,street1 ,dublin1       
8,march #ac1 #ahhc4    8,dear ,sir1  8,i
 have a distinct recollection of the    
,telephone4 ,we had a small private club
 meeting once each month for scientific 
purposes4 ,on referring to my           
note-books1 ,i find that there was a    
meeting on ,thursday evening1 ,october  
#eth1 #ahfe4 ,it was held in ,nassau    
,street1 at the residence ,mr4 ,horatio 
,yeates1 now in ,australia1 and brother 
of ,mr4 ,stephen ,yeates4 ,the          
,telephone was upstairs1 in the third   
story of the house1 and the voice heard 
in the hall4 ,mr4 ,vereker1 of the ,bank
 of ,ireland1 ,mr4 ,john ,rigby1 of     
rifle celebrity1 the two ,mr4 ,yeates1  
and1 ,i think1 ,mr4 ,tuke1 were present 
with myself4 ,there were some others1   
whom ,i cannot now recollect1 but our   
club was small4  8,rigby sang           
#8,patrick's ,day' and #8,god save the  
,queen1' and various questions were     

asked and answered4 ,the separate words 
were most distinct1 the singing less so2
 but there was no difficulty in         
recognising the individual who spoke by 
his voice4  8,being much interested in  
the subject1 ,i got ,mr4 ,yeates to     
allow the apparatus to be shewn at a    
,conversazione 7,presbyterian ,young    
,men's7 at the ,rotunda on ,october #ab1
 at #h ,p4,m4 ,his assistant1 ,mr4      
,tuke1 took charge of it that night4 ,it
 was placed in a side room off the main 
round room of the buildings4  8,i       
exhibited at the ,october #eth meeting  
of our club a specimen termed #8,locust 
gum1' probably derived from some        
,robinia1 but really can tell you       
nothing more about it4 ,there is merely 
a brief note of it in my private        
memoranda4        8,yours1 dear ,sir1   
,believe me very truly1                 
8,william ,frazer1       8,fellow and   
,examiner1 ,royal ,college of ,surgeons1
      8,ireland1 ,member of ,council1   
,royal ,irish      8,academy1 c40       

8,silvanus ,p4 ,thompson1 ,esq41        
,university ,college1 ,bristol40        
,,appendix ,i4  ,,comparison ,,of       
,,reis',s ,,transmitters ,,with ,,recent
 ,,instruments4   ,any one who compares 
together the many different forms of    
,reis's ,transmitters cannot fail to    
notice that amidst the great variety of 
form1 two essential points are preserved
 throughout1 the presence of which is   
fundamental4 ,these two essentials are1 
firstly1 the tympanum to collect the    
voice-waves1 and1 secondly1 an electric 
mechanism1 consisting of two or more    
parts in loose or imperfect contact with
 each other1 and so arranged in         
combination with the tympanum that the  
motions of the latter should alter the  
degree of contact1 and consequently     
interrupt1 to a greater or less degree1 
the current of electricity flowing      
between the contact-pieces4 ,it was of  
course familiar to all electricians1    
long before ,reis1 that a bad1 or       
imperfect1 or loose contact in a circuit

 offered a resistance and interrupted   
the flow of an electric current4 ,in all
 ordinary telegraphic and electric      
apparatus great care was taken to avoid 
loose and imperfect contacts by using   
clamping-screws and solid connectors4   
,but ,reis1 having made up his mind 7see
 p4 #gg7 that the action due to the     
magnetising current must vary in a      
manner corresponding with1 and therefore
 proportional to1 the vibrations of the 
voice1 utilised this property of        
imperfect contacts which alter their    
resistance according to the degree of   
contact1 by arranging his mechanism so  
as to apply the voice to vary the degree
 of contact4 ,this was the essence of   
his transmitters4 ,in other words1 he   
applied the voice to control or moderate
 the strength of the current generated  
by a battery4 ,his 8interruptors0 may   
therefore with propriety be called      
8electric current contact regulators20  
and put into technical language1 the    
essence of this part of his invention   

lay in the combination with a tympanum  
of electric current regulators working  
upon the principle of variable contact4 
,in another appendix is discussed the   
precise nature of that which occurs at a
 point of variable or imperfect contact1
 and which results in a corresponding   
change of electrical resistance when the
 degree of contact is varied4 ,suffice  
it to say here that it is impossible to 
vary the degree of contact between two  
bodies which are lightly pressing one   
against the other1 and through which an 
electric current is flowing1 without    
altering the resistance offered to the  
current by this joint in the circuit4   
,if the two surfaces are pressed        
together1 so that there is a good       
contact1 the current flows more freely1 
finding less resistance4 ,if1 on the    
other hand1 by altering the pressure or 
the amount of surface exposed1 we change
 the degree of contact and cause fewer  
atoms of one piece to touch those of the
 other piece1 the current meets with    

greater obstruction and cannot flow with
 such strength as before3 it is         
partially 8interrupted10 to use the     
expressive term employed by ,reis4  ,now
 this operation of varying the degree of
 pressure in order to vary the          
resistance of the interrupter or contact
 regulator1 was distinctly contemplated 
by ,reis4 ,we find his definite         
instructions1 for example 7see p4 #ge71 
for arranging the relative lengths of   
the two parts of the curved lever in one
 of his transmitters1 so that the       
movement of one contact-piece may act on
 the other contact-piece with the       
greatest possible force2 in other words1
 he shortened his lever at the working  
end1 sacrificing its range of motion in 
order to get a greater range of pressure
 at the contact-point4  ,it has often   
been said1 but incorrectly1 that ,reis  
intended his 8interruptors0 or contact  
regulators to make and break the        
electric circuit abruptly in the manner 
of a telegraphic key worked by hand4 ,no

 doubt in the mouth of a professional   
telegraph operator the words            
8interrupting0 the circuit1 and         
8opening0 and 8closing0 the circuit1 do 
now-a-days receive this narrow technical
 meaning4 ,but ,reis was not a          
professional telegraph operator3 he did 
not 7see p4 #hg7 even know the signals  
of the ,morse code1 and it is           
self-evident that he did not use the    
terms in any such restricted or         
unnatural sense as abrupt               
8make-and-break10 because he proposed at
 the outset to interrupt the current in 
a manner represented by the gradual rise
 and fall of a curve1 stating           
emphatically in his very first memoir on
 telephony 7p4 #ee71 that to reproduce  
any tone or combination of tones all    
that was necessary was 8to set up       
vibrations whose curves are like those0 
of the given tone or combination of     
tones4 ,moreover1 in the construction of
 almost all his transmitters1 even in   
the very first--the model of the human  

ear--he purposely introduced certain    
parts which could have no other effect  
than to prevent the occurrence of       
complete breaks in the continuity of the
 current4 ,in fact1 instead of using    
rigid supports for his interruptor1 he  
mounted one or both of the contact-parts
 with springs1 so that one should follow
 the movement of the other with a gentle
 pressure never amounting to absolute   
break1 except perhaps in the accidental 
case of a too loud shout4 ,by employing 
these following-springs1 he introduced1 
in fact the element of elasticity into  
his interruptor2 and clearly he         
introduced it for the very purpose of   
avoiding abrupt breaking of the contact4
 ,in the first form ,fig4 #e1 p4 #af    
7the 8ear071 there was one spring2 in   
the fourth form1 ,figs4 #i and #aj1 p4  
#ba 7the 8bored block071 there were two 
springs1 one of steel1 curved1 and one1 
a straight but springy strip1 of copper2
 in the eighth form 7the 8lever0 form71 
,fig4 #ad1 p4 #be1 there were two       

springs2 in the ninth form1 ,fig4 #ae1  
p4 #bf1 there was a springy strip of    
brass4 ,in the final form1 ,figs4 #ag   
and #ah1 p4 #bg 7the 8square-box0       
pattern71 there was1 it is true1 a      
springy strip of copper1 but the light  
adjustment of contact was in this form  
obtained1 not by a spring1 but by the   
inertia of the upper contact-piece which
 by its own weight pressed gently upon  
the lower contact-piece4 ,in every one  
of these forms1 except the last1 there  
was moreover an adjusting-screw to      
determine the exact degree of initial   
pressure between the contact surfaces4  
,doubtless the difficulty of adjusting  
this screw to give the exact degree of  
contact1 enhanced as that difficulty was
 in consequence of the liability of the 
membraneous tympanum to become flaccid  
by the moisture of the breath1 induced  
,reis to think that the later form of   
the apparatus in which this adjustment  
was no longer retained would be more    
easy to use1 or1 as he says in his      

,prospectus1 more accessible to others4 
,yet undoubtedly the absence of the     
spring at the contacts led some persons 
to fancy that the instrument was        
intended to be shouted or sung to so    
loudly that every vibration should make 
the upper contact-piece jump up from the
 lower1 and as ,professor ,mller even   
suggests 7p4 #ih71 produce a spark6 ,but
 such a manner of using the instrument  
would entirely defeat ,reis's most      
fundamental principle1 that the         
interruptions should be such as to      
correspond to the undulating curve which
 represents the pressure due to         
vibration of the sound-wave2 the        
possibility of representing the degree  
of pressure by a curve being one of the 
two principles set forth in his paper   
8on ,telephony0 7p4 #ee71 in which he   
remarks1 that 8,taking my stand on the  
preceding principles1 ,i have succeeded 
in constructing an apparatus by means of
 which ,i am in a position to reproduce 
444 even to a certain degree the human  

voice40 ,reis was perfectly well aware1 
as his curves show1 that a complicated  
sound-wave does not consist invariably  
of one condensation followed by one     
rarefaction1 but that there are all     
sorts of degrees of condensation which  
may follow one another1 and all capable 
of being represented by a curve4 ,if all
 sounds consisted of one rarefaction    
following immediately after each one    
condensation there might be some        
propriety in proposing that after each  
8make0 of contact there should be a     
8break0 in the sense of an abrupt or    
complete breach in the continuity of the
 current4 ,but1 obviously1 the fact that
 one condensation may follow another    
without a rarefaction between 7which    
,reis's curves show that he knew7 must  
be amply sufficient to prove that on    
,reis's own principle his interruptor   
was meant to produce variations in the  
degree of contact in exact              
correspondence with the variations in   
the degree of pressure1 whatever these  

might be4 ,had he not meant this1 he    
could not have talked about 8taking his 
stand0 on the principle of representing 
varying pressures by an undulatory      
curve4 ,now1 from what has been adduced1
 the following points are clear3--      
,firstly1 that the contact-regulator    
which ,reis combined with the tympanum  
was meant to interrupt the current1 more
 or less1 according to the varying      
movements imparted to it by the voice4  
,secondly1 that ,reis intended such     
interruptions or variations of contact  
to be proportional to1 or to            
8correspond0 with1 the variations       
indicated by the undulatory curve of    
varying pressures4  ,thirdly1 that for  
the purpose of preventing the occurrence
 of abrupt breaks in the continuity of  
the circuit1 he used springs and        
adjusting screws1 and in one form       
availed himself of the inertia of the   
moving parts to attain a similar end4   
,it is also clear from his own          
prospectus1 that he was aware that for  

the simpler and ruder purpose of        
transmitting musical airs1 in which the 
number of the vibrations is the only    
consideration and where each single     
condensation is actually followed by a  
rarefaction1 actual abrupt breaks in the
 continuity of the circuit are          
admissible4 ,reis chose this simple case
 as the one capable of being readily    
grasped by a general audience1 though it
 was obviously only a partial           
explanation of the action of the        
apparatus in the simplest case that     
could be presented4         99       99 
99       99       99  ,turning now to   
some of the more modern transmitters1 we
 will inquire how far ,reis's           
fundamental principles are involved in  
their construction4 ,we will first take 
,berliner's transmitter1 of which ,fig4 
#dc is a drawing1 reproduced from the   
sketch in the specification of his      
,british ,patent4 ,this transmitter     
consists of a tympanum of thin metal to 
collect the sound-waves1 and behind it  

is attached an interrupter or current   
regulator1 identical in almost every    
respect with that of ,reis4 ,one of the 
contact-pieces1 marked ,e1 circular in  
form1 is fixed to the centre of the     
tympanum1 and vibrates with it1         
precisely as in ,reis's latest1 and in  
some also of his earlier instruments4   
,against this there rests in light      
contact a second contact-piece1 in the  
form of a small blunt spike1 ,f1 screwed
 into a short arm1 loosely jointed to   
the part ,n1 where the circuit is       
connected4 ,as in ,reis's latest        
transmitter 7,fig4 #ag1 p4 #bg71 so     
here1 the contact-pieces are kept in    
contact by gravity4 ,when any person    
talks to the tympanum it vibrates1 and1 
as a result1 the degree of contact      
between the two surfaces is varied1     
resulting in a greater or less          
interruption of the current1 the inertia
 of the upper contact-piece1 serving to 
prevent complete abrupt 8break0 of the  
circuit1 except under unusually strong  

vibrations4 ,in fact1 if the speaker    
talks too loudly when speaking into     
,berliner's transmitter1 he will cause  
abrupt breaks to occur instead of       
partial interruptions2 and a rattling   
noise comes in to confuse the speech at 
the receiving end of the line4 ,but this
 is precisely what occurs in a ,reis's  
transmitter if one talks too loudly to  
it4 ,it is obvious that if ,berliner's  
transmitter is a 8make-and-break0       
instrument1 so is ,reis's1 because the  
principle of action is identical3 and it
 is also obvious that if ,berliner's    
instrument is capable of varying the    
resistance at the contact-points by     
interrupting the current in a manner    
corresponding to the pressures of the   
air in the sound-waves1 so also is      
,reis's instrument4  ,illustration3     
,fig4 #dc4  ,it is a fact that in       
,berliner's instrument it is usual to   
make the contact-pieces1 or one of them1
 of hard artificial coke-carbon1 as this
 substance will neither fuse nor rust4  

,but ,berliner's transmitter will       
transmit speech perfectly if the contact
 parts be of brass1 silver1 platinum1   
carbon1 or almost any other good        
conductor4 ,in most of ,reis's          
instruments the contact-pieces were     
usually of platinum2 but they work quite
 as well if artificial coke-carbon is   
substituted4 ,in fact1 ,reis's principle
 of variable and elastic contact is     
applicable to contact-pieces of any     
material that is a good enough conductor
 of electricity and hard enough for the 
purpose4 ,the main improvement in       
,berliner's transmitter is the          
substitution of the metal tympanum for  
the membraneous one1 which was liable to
 become flabby with moisture4           
,illustration3 ,fig4 #dd4  ,we pass on  
to ,blake's transmitter1 which is the   
one more generally used in ,great       
,britain than any other4 ,the drawing1  
,fig4 #dd1 of this instrument is taken  
from the specifications of ,blake's     
,british ,patent1 and shews all that    

concerns the contact-parts4 ,it does not
 show the accessories1 the              
induction-coil1 or the form of adjusting
 screw and frame peculiar to this       
instrument4 ,inspection of the figure   
shows that this transmitter consists of 
a mouthpiece in the form of a conical   
hole bored through a stout plank of     
wood1 and closed at the back by a metal 
tympanum of exactly the same size as    
that of ,reis1 behind which the         
interruptor is placed1 precisely as in  
some of ,reis's instruments4 ,in this   
interruptor both the contact-parts are  
supported on springs1 resembling1 even  
in the curve given to them1 the springs 
,reis used4 ,the first of the           
contact-pieces is a small metal spike4  
,concerning it ,mr4 ,blake remarks 7page
 #d of ,specification73--8,it is        
desirable that it should be formed of1  
or plated with1 some metal1 like        
platinum or nickel1 which is not easily 
corroded4 ,it may be attached directly  
to the diaphragm1 but ,i prefer to      

support it independently1 as shewn1 upon
 a light spring40 444 8,this method of  
supporting the electrode ensures its    
contact with the other electrode under  
some circumstances when otherwise they  
would be liable to be separated and the 
circuit broken40 ,in fact this spring   
serves functions precisely identical    
with those of the springs used by ,reis4
 ,the second of the contact-pieces may  
be described as a mass of metal at the  
end of a spring4 ,of it the patentee    
remarks3--8,this weight may be of metal 
which may serve directly as the         
electrode1 but ,i have obtained better  
results by applying to it1 at the point 
of contact with the other electrode1 a  
piece of gas-coke or a hard-pressed     
block of carbon40 ,as a matter of fact1 
a mass of silver or of nickel or of     
platinum will transmit talking          
perfectly1 but these metals1 though     
better conductors1 are more liable to   
corrode and fuse1 and may require       
therefore more frequent renewal1 than   

gas-coke4 ,since1 then1 it is immaterial
 to the action of a ,blake transmitter  
what substance is used for the          
contact-pieces1 it is clear that the    
principle of employing an interruptor   
mounted on springs is the real feature  
of the instrument4 ,reis also mounted   
his interrupters with springs1 and for  
the very same purpose4 ,the function of 
the weight on the second spring of the  
,blake transmitter is to resist the     
movement of the tympanum1 and to 8modify
 by its inertia the variations of       
pressure0 between the two               
contact-pieces4 ,in other words1 it acts
 partly as ,berliner's transmitter1 by  
inertia4 ,so did one of ,reis's         
instruments1 as we have seen4 ,in the   
,blake instrument there is the happy    
idea of applying both the               
spring-principle and the                
inertia-principle at once4 ,yet1 in     
spite of this1 if the speaker shouts too
 loudly into a ,blake transmitter1 he   
will cause abrupt breaks between the    

contact-pieces instead of producing     
partial interruptions in the contact1   
and in that case speech will1 as heard  
at the other end of the line1 be spoiled
 by a rattling noise4 ,it is possible1  
also1 with ,reis's instruments to spoil 
the articulation by shouting too loudly1
 and causing actual abrupt breaks in the
 continuity4 ,if ,blake's interruptor   
can be worked as a make-and-break in    
this sense1 so can ,reis's3 for there is
 not one of the features which is       
essential to ,blake's instrument that   
cannot be found in ,reis's also4  ,by   
way of further carrying out the         
comparison between ,reis's methods of   
combining his tympanum with his         
contact-regulator1 and the methods      
adopted by later inventors1 we give1 in 
,fig4 #de1 ten comparative sketches1 the
 first five of which illustrate ,reis's 
methods4 ,in these sketches the only    
liberty taken is that of representing no
 more of the instruments than the actual
 parts wanted in the comparison4 ,no4 #a

 represents the working-parts of ,reis's
 first model ear1 with its curved lever1
 platinum-tipped spring1 and adjusting  
screw4 ,no4 #b shows the springs1 screw1
 and contact-pieces of ,reis's          
bored-block transmitter 78fourth form30 
compare ,figs #i and #aj1 p4 #ba74 ,no4 
#c shows the curved lever1 the springs1 
and the adjusting screw of ,reis's      
eighth transmitter 78lever0 form74 ,no4 
#d gives the working parts of ,reis's   
ninth transmitter1 described in detail  
on p4 #bg4 ,no4 #e1 in which the        
tympanum is placed in a vertical        
position1 merely for convenience of     
comparison with the other figures1 shows
 the working parts of ,reis's final form
 of instrument1 in which gravity and the
 inertia of the upper contact-piece     
enabled him to dispense with the        
adjustment of spring and screw4 ,no4 #f 
shows in profile ,berliner's            
transmitter1 which may be instructively 
compared with ,no4 #e4 ,no4 #g shows the
 working part of ,blake's transmitter1  

which should be compared with ,nos4 #b  
and #d3 even the curve of the springs   
imitates that adopted by ,reis4 ,nos4   
#h1 #i1 and #aj are forms of transmitter
 devised by ,edison4 ,no4 #h is copied  
from ,fig4 #aj of the specification of  
,edison's ,british ,patent4 ,it will be 
seen that here there is an interruptor  
placed on each side of the tympanum1 and
 that each interruptor consists of a    
short spike mounted on a spring and     
furnished with an adjusting-screw4      
8,platina foil disks10 says the         
inventor1 are to be secured to each side
 of the diaphragm1 and against these    
disks1 as in ,reis's instruments1 press 
the contact-points of the interruptors4 
,the patentee also states 7p4 #g of his 
,specification71 that for these         
contact-points 8any substance not liable
 to rapid decomposition0 may be used4   
,this term includes all the substances  
used by ,reis1 and a great many others4 
,it will therefore be seen that this    
whole device is nothing more than a     

,reis transmitter with the contact parts
 duplicated4 ,yet this instrument was   
intended by ,edison to transmit speech1 
and will1 like ,reis's instrument1      
transmit speech if properly used4 ,no4  
#i of the set of sketches is taken from 
,fig4 #be of ,edison's ,british         
,specification1 but omits the           
induction-coil and other accessories1   
retaining the parts wanted for          
comparison4 ,the patentee thus describes
 the parts figured4 8,the               
tension-regulator meaning thereby the   
interruptor or contact-regulator is made
 of platina-foil upon the surface of two
 soft rubber tubes2 one on the          
diaphragm1 the other on the             
adjusting-screw40 ,it is interesting to 
note here how the ingenuity of the later
 inventor led him to vary the           
construction adopted by the original    
inventor in substituting an elastic     
cushion of soft rubber for the springs  
of the older instruments4 ,but the      
principle of combining a tympanum with a

 contact-regulator1 which was ,reis's   
fundamental notion1 is here also the    
leading idea2 and the further idea of   
obviating abrupt breaks in the current  
by applying elastic supports is also    
carried out4 ,edison even copies ,reis  
in having an adjusting-screw1 and he    
applies the very same                   
substance--platinum foil--which ,reis   
used in his very first and his very last
 transmitter4 ,edison's transmitter     
transmits speech very fairly1 even      
without any of such later accessories as
 induction-coils2 and why should it not8
 ,it is constructed on the very lines1  
nay1 with details almost identical with 
those prescribed by ,reis in describing 
his invention4 ,it embodies those       
fundamental ideas which ,reis set before
 him when he said1 8,taking my stand    
upon the preceding principles1 ,i have  
succeeded40  ,illustration3 ,fig4 #de4  
,the last of the ten sketches of ,fig4  
#de is taken from ,edison's first       
,american ,patent specification ,no4    

#bjc1jad1 filed ,july #bj1 #ahgg1 and   
shows a duplicated interrupter with     
springs and adjusting-screws combined   
with a tympanum4 ,further comment on    
this arrangement is needless1 save to   
remark that in this patent for 8speaking
 telegraphs10 ,edison himself describes 
the contact-apparatus which ,reis termed
 an 8interrupter10 as a                 
8circuit-closer10 or in another place as
 8circuit-breaking connections10 and1 in
 his ,british ,patent quoted above1 as a
 8tension-regulator40 ,it is evident    
that if ,reis could transmit speech by  
an interrupter which closed and opened  
the circuit 7always in proportion to the
 vibrations7 there is no reason why     
,edison seventeen years afterwards      
should not accomplish the same result by
 a similar means4 ,but it has lately    
been fashionable to deny that any such  
device as an interrupter mounted on     
springs can transmit speech at all6  ,we
 have now compared with ,reis's         
transmitters several of the more modern 

inventions4 ,it would be possible to    
carry comparison further were that      
course needed4 ,we have not thought it  
worth while to rake up ,edison's now    
discarded lamp-black button transmitter2
 and we have not yet spoken of          
,crossley's transmitter nor of          
,theiler's transmitter1 nor of their    
parent the ,hughes' microphone1 nor of  
dozens of other forms4 ,in some of these
 there is no specific 8tympanum10 but   
only a sounding-board of pine-wood1 and 
in most of them the points of           
loose-contact1 where interruption more  
or less complete may occur1 are         
multiplied4 ,but they all come back in  
the end to ,reis's fundamental idea1    
namely that of setting the voice to vary
 the degree of contact in a mechanism   
which he called an interruptor1 and     
which others have called a              
current-regulator 7or1 less correctly1 a
 tension-regulator7 which1 because the  
degree of contact between its parts was 
varied1 caused those parts to offer more

 or less resistance to the flow of the  
current1 and thereby threw it into      
vibrations corresponding to those of the
 sound-wave impressed upon the tympanum4
 ,there is not a practical transmitter  
used in any of the telephone exchanges  
of ,great ,britain to-day that does not 
embody this principle4  ,reis did1      
indeed1 penetrate to the very heart the 
principles necessary to be observed in a
 successful telephone4 ,he was master of
 the situation4 ,for1 as in every       
practical transmitter in use to-day1 so 
in his transmitter1 there was a loose   
contact in the circuit so arranged that 
the voice could act upon it1 and thereby
 regulate the strength of the current4  
,if you eliminate this part of the      
apparatus1--screw up the loose-contacts 
of your transmitters1 so that your      
voices cannot affect them1--what will   
your telephones be worth8 ,no3 the      
essential principle of the              
transmitter--8,das ,telephon0           
emphatically as its inventor styled     

it--is variable contact2 and that       
all-essential principle was invented and
 applied for the purpose of transmitting
 speech by ,philipp ,reis in #ahfa4  ,if
 this does not suffice as a claim for   
the invention of the ,telephone         
transmitter1 it may well be wondered    
what will4 ,we can dispense with all    
other features save this one4 ,we can   
even dispense with the tympanum or      
diaphragm which ,reis introduced1 and   
can operate on the contact-parts without
 the intervention of this part of the   
combination4 ,we can use the very metals
 which ,reis used1 and dispense with    
lamp-black and all the fallacious       
rubbish that has been subsequently      
devised about semi-conductors1 whatever 
that term may mean4 ,we can even        
dispense with springs and adjusting     
screws4 ,but with the principle of      
variable contact we can not dispense4   
,that which alone is indispensable      
,philipp ,reis discovered4              
,,appendix ,,ii4  ,,on ,,the ,,variation

 ,,of ,,electric ,,resistance ,,at ,a   
,,point ,,of ,,imperfect ,,contact ,,in 
,a ,,circuit4   ,ever since electricians
 had experimented with voltaic currents1
 and especially since the introduction  
of the electric telegraph1 it had been a
 familiar fact that a loose or imperfect
 contact in the circuit caused a        
resistance to the flow of the current   
and interrupted it more or less         
completely4 ,to obviate the occurrence  
of loose or imperfect contacts1         
binding-screws were invented2 and many  
were the precautions taken to make tight
 contacts at joints in the line1 the    
resistance of which it was desirable to 
maintain at a minimum4 ,young           
telegraphists were particularly         
instructed to press their keys well down
 in signalling1 because a light contact 
would offer some resistance which1 on an
 increase of pressure1 would disappear4 
,in fact1 it was generally well known   
that the resistance of two pieces of    
metal or other conducting material in   

contact with one another might be made  
to vary by varying the goodness or      
badness of the contact with the         
application of more or less force4 ,this
 fact was known to apply to good        
conductors1 such as copper and other    
metals1 and it was known to apply also  
to non-metallic conductors1 such as     
plumbago4 ,plumbago points were used by 
,varley for the contacts of relays2 it  
having been found that points of        
platinum were liable to become fused    
together with the passage of the        
current1 and by so sticking rendered the
 instrument useless4 ,since plumbago was
 known to be infusible1 it was hoped    
that a plumbago contact would prove more
 reliable4 ,in practice1 however1 the   
plumbago relay did not turn out so well4
 ,true it did not fuse1 or stick1 or    
rust2 but it was even more liable than  
platinum to form imperfect contacts1 the
 resistance of the light contact being  
so high that a sufficient current did   
not pass4 ,it is not known whether other

 non-metallic substances were tried2    
probably not1 because of non-metallic   
substances plumbago is one of the few   
that are good conductors4  ,according to
 ,edison 7,british ,patent1 ,no4 #gib1  
#ahhb71 compressed graphite is a        
substance of great conductivity4        
,according to ,faraday 7#8,exp4 ,res4'  
vol4 i4 p4 #bd71 retort-carbon is an    
excellent conductor4 ,both graphite and 
retort-carbon agree with the metals in  
the property that the electric          
resistance offered at a point of contact
 between them varies when the pressure  
at the contact is varied4 ,it is indeed 
remarkable through what wide ranges of  
resistance the contact between two good 
conductors may vary4 ,the resistance of 
contact between two pieces of copper may
 be made to vary in a perfectly         
continuous manner by changes of pressure
 through a range1 according to ,sir ,w4 
,thomson1 from a small fraction of one  
ohm1 up to a resistance of many thousand
 ohms4 ,the same is true of silver1     

brass1 and many other good conductors1  
including graphite and retort-coke1     
though with the latter materials the    
range of resistances is not so great4   
,with partial conductors1 such as oxide 
of manganese1 sulphide of copper1       
sulphide of molybdenum1 c41 and with bad
 conductors1 such as lamp-black and     
selenium1 whose conductivity is millions
 of times less than that of graphite1   
copper1 and other good conductors1 it is
 impossible to get equally wide         
variations of resistance1 as the amount 
of pressure at a point which will bring 
the bad conductors into intimacy of     
contact1 will not turn them into good   
conductors4 ,platinum being in the      
category of good conductors1 is amongst 
those substances which yield a very wide
 range of electrical resistances at the 
contact-points which are submitted to   
varying pressures4  ,with the very      
highest conductors1 such as silver and  
copper1 the electrical range of         
contact-resistance is higher than with  

those of lesser conductivity1 such as   
lead1 platinum1 graphite1 and           
retort-coke4  ,but though the range of  
variation in electrical resistance at   
contacts is highest for the best        
conductors1 there comes in another      
element1 namely1 the range of distance  
through which the contact-pieces1 or    
either of them1 must be moved in order  
to pass through the range of variations 
of resistance4 ,this is quite a         
different matter1 for here the best     
conductors have the smallest range1 and 
some that are not so good a greater     
range4 ,in any case the available range 
of motion is very small--to be measured 
in minute fractions1--millionth-parts1  
perhaps1--of an inch4 ,so far as        
experiments go1 however1 silver has the 
smallest range of all1 then gold1 then  
copper4 ,platinum and nickel have a     
considerably wider range1 plumbago and  
retort-coke a still wider one4  ,it is  
an extremely difficult matter to decide 
what is the precise nature of that which

 goes on at a point of contact between  
two conductors when the pressure at the 
point is altered4 ,the principal        
suggestions hitherto advanced have been 
that the change of resistance observed  
is due3--      7a7 ,to the mere changes 
in the amount of surface in contact4    
7b7 ,to a change in the resistance of   
the substance of the     conductor      
itself4      7c7 ,to the formation of a 
minute voltaic 8arc10 or electric       
discharge4      7d7 ,to the change in   
the thickness of the intervening film of
     air4      7e7 ,to the change in    
resistance of the parts in contact      
consequent on the evolution of heat by  
the current4  ,it is admitted that this 
last suggestion1 though it might account
 for a difference between different     
substances1 in so far as they differ    
from one another in the effect of heat  
upon their specific resistance1 implies 
as a preliminary fact that the amount of
 surface in contact shall be varied by  
the pressure4 ,no convincing proof has  

yet been given that the alleged layer of
 air or other gases has any real part to
 play in the phenomena under discussion4
 ,nor can the hypothesis1 that minute   
voltaic arcs are formed at the contact  
be regarded as either proven or         
probable4  ,the only two theories that  
have really been investigated are 7a7   
and 7b7 of the above series4 ,of these  
two 7b7 is certainly false1 and 7a7 is  
probably1 at least to a very large      
extent1 true4  ,it is often said by     
persons imperfectly acquainted with the 
scientific facts of the case1 that      
carbon is used in                       
telephone-transmitters1 because the     
resistance of that substance varies with
 the pressure brought to bear upon it1  
whilst with metals no such effect is    
observed4 ,this statement1 taken        
broadly1 is simply false4 ,mr4 ,edison  
has1 indeed1 laid claim to the          
8discovery0 7vide ,prescott's           
#8,speaking ,telephone1' p4 #bbc71 that 
8semi-conductors10 including powdered   

carbon and plumbago1 vary their         
resistance with pressure4 ,all that ,mr4
 ,edison did discover was that certain  
substances1 whose properties of being   
conductors of electricity had been known
 for years1 conducted better when the   
contact between them was screwed up     
tightly than when loose4 ,the           
experiments made to test this alleged   
8property0 of carbon are absolutely     
conclusive4 ,the author of this book has
 shown#ci that when a rod of dense      
artificial coke-carbon1 such as is used 
in many forms of telephone transmitters1
 such as ,crossley's for example1 is    
subjected to pressure varying from less 
than one dyne per square centimetre up  
to twenty-three million times that      
amount1 the resistance of the rod did   
not decrease by so much as one per cent4
 of the whole4 ,in this case any doubt  
that might have been introduced by      
variable contact was eliminated at the  
outset by taking the precaution of      
electro-plating the contacts4  ,in      

#ahgi1 ,professors ,naccari and         
,pagliani1 of the ,university of ,turin1
 published an elaborate series of       
researches#dj on the conductivity of    
graphite and of several varieties of    
coke-carbon1 and found1 even with great 
changes of pressure1 that the changes of
 electric resistance were practically   
too small to be capable of being        
measured1 and that the only changes in  
resistance appreciable were due to      
changes of contact4  ,in ,january #ahhb1
 ,mr4 ,herbert ,tomlinson communicated  
to the ,royal ,society#da the results of
 experiments on a number of electric    
conductors4 ,the change of conductivity 
by the application of stress was found  
to be excessively small4 ,for carbon it 
was less than one-thousandth part of one
 per cent4 for an increase of fifteen   
lbs4 on the square inch in the pressure4
 ,for iron it was slightly greater1 and 
for lead nearly twice as great1 but with
 all other metals less4 ,if this alleged
 property were the one on which the     

action of telephone transmitters        
depended1 then lead ought to be twice as
 good a substance as graphite2 whereas  
it is not nearly so good4  ,professor   
,w4 ,f4 ,barrett1 in #ahgi1db made some 
experiments on the buttons of compressed
 lamp-black used in ,edison's           
transmitter1 and found that when an     
intimate contact was satisfactorily     
secured at the beginning1 8pressure     
makes no change in the resistance40  ,in
 the face of all this precise evidence1 
it is impossible to maintain the theory 
that the electric resistance of plumbago
 or of any other such conductor varies  
under pressure4 ,the only person who has
 seriously spoken in favour of the      
theory is ,professor ,t4 ,c4            
,mendenhall1 but in his experiments he  
took no precautions against variability 
of contacts1 so that his conclusions are
 invalid4  ,more recently still1 ,mr4   
,o4 ,heaviside and ,mr4 ,shelford       
,bidwell have experimented on the       
variations of resistance at points of   

contact4#dc ,mr4 ,heaviside's           
experiments were confined to contacts   
between pieces of carbon1 and though    
extremely interesting as showing that   
the resistance of such contacts are not 
the same1 even under constant pressure1 
when currents of different strength are 
flowing1 do not throw much light on the 
general question1 because they leave out
 the parallel case of the metals4 ,mr4  
,bidwell's very careful researches were 
chiefly confined to carbon and bismuth4 
,the choice is unfortunate1 because     
bismuth the most fusible and worst      
conductor amongst metals 7save only     
quicksilver7 is the one metal least     
suited for use in a telephone           
transmitter4 ,mr4 ,bidwell's            
conclusions1 so far as they are         
comparative between carbon and 8the     
metals10 are therefore necessarily      
incomplete4  ,professor ,d4 ,e4 ,hughes1
 whose beautiful invention1 the         
,microphone1 attracted so much attention
 in #ahgh1 has lately thrown the weight 

of his opinion in favour of the view    
that with carbon contacts the effect is 
due chiefly to an electric discharge or 
arc between the loosely-contiguous      
parts4 ,but ,professor ,hughes's        
innumerable experiments entirely upset  
the false doctrine that a               
8semi-conductor0 is necessarily required
 for the contact-parts4 ,speaking       
recently1#dd he has said3 8,i tried     
everything1 and everything that was a   
conductor of electricity spoke40 ,in    
#ahgh1 in a paper 8,on the ,physical    
,action of the ,microphone10 ,professor 
,hughes stated3#de 8the best results as 
regards the human voice were obtained   
from two surfaces of solid gold40       
,hughes also found carbon impregnated   
with quicksilver in its pores to        
increase its conducting power to work   
better than non-metallised carbon of    
inferior conductivity4 ,quite lately    
,mr4 ,j4 ,munro has constructed         
successful transmitters of metal gauze1 
having many points of loose-contact     

between them4  ,it seems1 therefore1    
much the most probable in the present   
state of investigations1 that the       
electric resistance of a contact for    
telephonic purposes is determined solely
 by the number of molecules in contact  
at the surface1 and by the specific     
conductivity of those molecules4 ,the   
element of fusibility comes in to spoil 
the constancy of the surfaces in action2
 and hence the inadmissibility of       
general conclusions with respect to all 
metals drawn from the behaviour of the  
most fusible of them4 ,at a mere point  
in contact physically with another      
point1 there may be hundreds or even    
millions of molecules in contact with   
one another1 all acting as so many paths
 for the flow of the electric current4  
,an extremely small motion of approach  
or recession may suffice to alter very  
greatly the number of molecules in      
contact1 and the higher the specific    
conductivity of the substance1 and the  
denser its molecules1 the shorter need  

be the actual range of motion to bring  
about a given variation in the          
resistance offered4 ,just as in a system
 of electric lamps in parallel arc1 the 
resistance of the system of lamps       
increases when the number of lamps      
through which the current is flowing is 
diminished1 and diminishes when the     
number of lamps connecting the parallel 
mains is increased2 so it is with the   
molecules at the two surfaces of        
contact4 ,diminishing the number of     
molecules in contact increases the      
resistance1 and vice vers4 ,each        
molecule as it makes contact with a     
molecule of the opposite surface        
diminishes1 by so much relatively to the
 number of molecules previously in      
contact1 the resistance between the     
surfaces4 ,each molecule as it breaks   
from contact with its opposite neighbour
 adds to the resistance between the     
contact-surfaces4 ,it may therefore be  
that the variations of resistance which 
are observed at contacts between all    

conductors1 from the best to the worst1 
are all made up1 though they appear to  
pass through gradual and continuous     
changes1 of innumerable minute          
makes-and-breaks of molecular contact4  
,the very minuteness of each molecular  
make-or-break1 and the immense number   
that actually must occur at every       
physical 8point0 of contact1 explain why
 the effect seems to us continuous4 ,we 
owe1 moreover1 to ,mr4 ,edison#df the   
experimental proof that actual abrupt   
makes-and-breaks of contact can produce 
an undulating current when they recur   
very rapidly4 ,whether the heating      
action of the current itself may not    
also operate in changing the            
conductivity of the molecules which     
happen at the moment to be in contact is
 another matter4 ,it may be so2 but if  
this should hereafter be demonstrated1  
it will but confirm the contact-theory  
of these actions as a whole4  ,assuming1
 then1 broadly1 that the observed       
resistance at a point of contact is due 

to the number of molecules in contact   
and to their individual resistances1 it 
is evident that the property of varying 
resistance at contact ought to be most  
evident1 ceteris paribus1 in those      
substances which are the best conductors
 of electricity4 ,unfortunately1 the    
cetera are not paria1 for the question  
of fusibility comes in to spoil the     
comparison2 and carbon1 which has less  
fusibility than the metals1 is commonly 
credited with giving a better result    
than any4 ,this common opinion is1      
however1 based on comparisons made      
without taking into consideration the   
question of range of motion between the 
parts in contact1 and without taking    
into consideration the point that whilst
 some forms of carbon are excellent     
conductors1 others do not conduct at    
all4 ,in a telephonic transmitter so    
arranged that the actual range of motion
 shall be very small1 the metals are    
just as good as carbon--some of them    
better4 ,i have heard from a transmitter

 with contacts of pure bright silver    
better articulation than with any carbon
 transmitter4 ,and this is exactly what 
theory would lead one to expect4 ,as to 
the suggestion that plumbago makes a    
successful transmitter1 because it is a 
8semi-conductor0--whatever that term may
 mean#dg--;it is one of those           
suggestions which are peculiarly fitted 
to catch the unscientific mind as       
affording an easy explanation for an    
obscure fact2 unfortunately1 like a good
 many other similarly catching          
suggestions1 it is not true4 ,the very  
best conductor--silver--will serve to   
transmit articulate speech3 and so will 
the one of the very worst               
conductors--lamp-black6 ,so much for    
this fallacious doctrine of             
semi-conductors6  ,reis used for his    
contact-points substances which1 by     
reason of their non-liability to fuse or
 oxidize1 were customary in electrical  
apparatus1 and chiefly platinum4 ,in his
 earliest transmitter 7model ear71 and  

in his last1 platinum was used4 ,in his 
lever-form of transmitter1 so minutely  
described by von ,legat1 the material is
 not specified4 ,the lever-shaped       
contact-piece was to be a conductor1 and
 as light as possible1 and since all    
metallic parts are particularly         
described as metallic1 whilst this is   
not so described1 the obvious inference 
is that this was non-metallic4 ,the     
number of light1 non-metallic conductors
 is so few that the description         
practically limits choice to some form  
of hard carbon4 ,no other materials are 
named by ,reis1 but ,pisko says 7p4     
#ajc7 that brass1 steel1 or iron might  
be used for contacts4 ,any one of these 
materials is quite competent1 when made 
up into properly-adjusted               
contact-points1 to vary the resistance  
of a circuit by opening and closing it  
in proportion to the vibrations imparted
 to the contact-points4 ,that is what   
,reis's transmitter was intended to do1 
and did4 ,that is what all the modern   

transmitters--,blake's1 ,berliner's1    
,crossley's1 ,gower-,bell's1 ,theiler's1
 ,johnson's1 ,hunning's do1 even        
including ,edison's now obsolete        
lamp-black button transmitter4 ,mr4     
,shelford ,bidwell has very well        
summarized the action of the            
current-regulator in the following      
words3 8,the varying pressure produces  
alterations in the resistance at the    
points of contact in exact              
correspondence with the phases of the   
sound-waves1 and the strength of a      
current passing through the system is   
thus regulated in such a manner as to   
fit it for reproducing the original     
sound in a telephone40  ,reis           
constructed an apparatus consisting of a
 tympanum in combination with a         
current-contact-regulator1 or           
8interruptor10 which worked on this     
principle of variable contact1 and he   
called it 8,the ,telephone0 7see pp4    
#eg1 #he74 ,the very same apparatus we  
now-a-days call a                       

8,telephone-transmitter10 or simply a   
8transmitter40 ,it is curious to note   
that ,reis seems to have regarded his   
receiver or 8reproducing-apparatus0 as  
no new thing4 ,he says explicitly 7p4   
#ef7 that his receiver might be replaced
 by 8any apparatus that produces the    
well-known galvanic tones40 8,the       
,telephone0 was with ,reis emphatically 
the transmitter4 ,bell in #ahgf invented
 an instrument which would act either as
 transmitter or receiver1 and which1    
though never now used as transmitter1 is
 still called 8a ,telephone40 ,edison's 
8sound-telegraph10 or 8telegraphic      
apparatus operated by sound10 was       
patented in #ahgg4 ,in his specification
 he never called his transmitter a      
8telephone20 that name he reserved      
exclusively for his receiver4 ,he found 
it1 however1 convenient a year later to 
rechristen his transmitter as the       
8carbon telephone10 though throughout   
the whole of his specification neither  
8carbon0 nor 8telephone0 are mentioned  

in connection with the transmitter6     
,within that year ,hughes had brought   
out another instrument--8,the           
,microphone0--which1 like ,reis's       
instrument1 embodied the principle of   
variable contact4 ,hughes's instrument1 
usually constructed with contacts made  
of loose bits of coke-carbon1 was simply
 a ,reis's ,telephone minus the circular
 tympanum2 and the really important new 
fact it revealed1 was that very minute  
vibrations1 such as those produced by   
the movements of an insect1 when        
transmitted immediately through the     
wooden supports1 sufficed to vary the   
resistance of a telephonic circuit1     
though far too slight in themselves to  
affect it if they had to be first       
communicated to the air and then        
collected by a tympanum4 ,put a specific
 tympanum to a ,hughes's microphone1 and
 you get a ,reis's telephone4 ,take away
 the tympanum from a ,reis's telephone1 
and you get a ,hughes's microphone4     
,hughes is not limited to one material1 

nor is ,reis4 ,but the fundamental      
principle of the electrical part of each
 is identical4 ,the ,blake transmitter  
7,fig4 #dd71 and the ,berliner          
transmitter1 and also ,ldtge's          
microphone1#dh which was even earlier   
than that of ,hughes1 are all           
embodiments of the same fundamental     
principle of variable contact which     
,reis embodied in his 8,telephone40     
,the numerous experiments which ,reis   
made1 and the many forms of instruments 
which he devised1 prove his conviction  
of the importance of his invention to   
have been very deeply rooted4 ,he had   
indeed penetrated to the very soul of   
the matter4 ,he did not confine himself 
to one kind of tympanum1 he tried many1 
now of bladder1 now of collodion1 now of
 isinglass1 and now of thin metal4 ,he  
varied the forms of his instruments in  
many ways1 introducing the element of   
elasticity by springs and               
adjusting-screws4 ,though he chiefly    
employed one metal for his              

contact-pieces1 he did not limit himself
 to that one1 but left us to infer that 
the principle of variable contact was   
applicable to any good conductor1       
metallic or non-metallic4 ,he knew      
better1 indeed1 than to limit himself in
 any such fashion2 better1 indeed1 than 
some of the eminent persons who are now 
so willing to ignore his claims4 ,modern
 practice has taught us to improve the  
tympanum part of ,reis's invention1 and 
to obviate the inconveniences to which a
 membrane is liable3 in that part we    
have gone beyond ,reis4 ,but in the     
question of contact-points for opening  
and closing the circuit in              
correspondence with the vibrations1 we  
are only beginning to find how much     
,reis was a-head of us4 ,we have been   
thrown off the track--blinded           
perhaps--by the false trail of the      
8semi-conductor0 fallacy1 or by the     
arbitrary and unnatural twist that has  
been given by telegraphists to ,reis's  
expression1 8opening and closing the    

circuit10 forgetting that he practically
 told us that this operation was to be  
proportional to1 8in correspondence     
with10 the undulations of the tympanum4 
,when we succeed in freeing ourselves   
from the dominance of these later ideas1
 we shall see how much we still have to 
learn from ,philipp ,reis1 and how fully
 and completely he had grasped the      
problem of the ,telephone4  ,,footnotes3
  #ci #8,philosophical ,magazine1'      
,april #ahhb4  #dj #8,atti del ,r4      
,istituto ,veneto di ,scienze1' vol4 vi4
 ser4 #e4  #da ,proc4 ,roy4 ,soc4 ,no4  
#bah1 #ahhb4  #db ,see ,proc4 ,roy4     
,dubl4 ,soc4 ,feb4 #ag1 #ahgi4  #dc     
,vide #8,the ,electrician1' ,feb4 #aj1  
#ahhc4  #dd ,journal ,soc4 ,telegr4     
,engin4 and ,electricians1 vol4 xii4 p4 
#acg4  #de ,proc4 ,physical ,soc4 vol4  
ii4 p4 #bei1 #ahgh4  #df #8,journal     
,soc4 ,telegraphic ,engineers1' vol4 iv4
 p4 #aag1 #ahgd4  #dg ,the term         
8semi-conductor0 is very rarely used by 
electricians1 who prefer the term       

8partial conductor0 as being more       
correct4 ,moreover1 electricians1 from  
,faraday downwards1 are practically     
agreed in calling plumbago a good       
conductor1 and worthy of being          
classified by reason of its high        
conductivity along with the metals4 ,the
 substances known as 8semi-conductors0  
are those given in ,ferguson's          
#8,electricity1' p4 #di 7edition of     
#ahgc71 namely1 alcohol1 ether1         
dry-wood1 marble1 paper1 straw1 and ice4
 ,mascart and other eminent authorities 
agree in this classification4 ,it would 
tax even ,mr4 ,edison's unrivalled      
ingenuity to make of these materials a  
transmitter that should alter its       
resistance by pressure6  #dh ,ldtge's   
,german ,patent1 dated ,jan4 #ab1 #ahgh1
 describes a 8,universal ,telephone0 in 
which a tympanum was applied to convey  
vibrations to an interruptor made of    
hard coke-carbon4     ,,appendix ,,iii4 
,,comparison ,,of ,,reis',s ,,receivers 
,,with ,,recent ,,instruments4   ,the   

receivers invented by ,reis for the     
purpose of reconverting into audible    
mechanical vibrations the varying       
electric currents transmitted from the  
speaking end of the line were of two    
classes1 viz43  7#a47 ,those in which   
the magnetic expansion and contraction  
of a rod of steel or iron1 under the    
influence of the varying current1 set up
 mechanical vibrations and communicated 
them to a sound-board4  7#b47 ,those in 
which the current by passing round the  
coils of an electro-magnet caused the   
latter to vary the force with which it  
attracted its armature1 and threw the   
latter into corresponding mechanical    
vibrations4  ,the first of these        
principles is embodied in the           
8knitting-needle0 receiver described    
above and depicted in figures #bb  #bc  
on page #cc4 ,this receiver differs     
wholly from the later instruments of    
,bell1 and others1 and depended for its 
action upon the phenomenon of magnetic  
expansion discovered by ,page and       

investigated by ,joule4 ,it was well    
known before ,reis's time that when a   
needle or bar of iron was magnetised it 
grew longer1 and when demagnetised it   
grew shorter4 ,page detected the fact by
 the 8tick0 emitted by the bar during   
the act of magnetisation or             
demagnetisation4 ,joule measured the    
amount of expansion and contraction4 ,to
 these discoveries ,reis added two new  
facts2 first1 that if the degree of     
magnetisation be varied with rapid      
fluctuations corresponding to those of  
the sound waves impressed on the        
transmitter1 the expansion and          
contraction of the rod followed these   
fluctuations faithfully1 and therefore  
emitted at the receiving end sounds     
similar to those uttered at the         
transmitter4 ,secondly1 by employing a  
needle of steel instead of the bar of   
iron used by ,page1 ,reis obtained an   
instrument which once used could never  
become completely demagnetised on the   
cessation of the current2 it was        

thenceforth a permanent magnet1 and all 
that the fluctuating currents could do  
was to vary its degree of magnetisation4
 ,reis carefully explained in his memoir
 8,on ,telephony10 how the frequency of 
such fluctuations in the magnetising    
current could act in reproducing the    
pitch1 and further1 how the amplitude of
 the fluctuations set up vibrations of  
corresponding amplitude in the rod3 he  
added with significance1 that the       
quality of the reproduced note depended 
upon a number of variations of amplitude
 occurring in a given time4 ,his theory 
of these actions was that the atoms 7or 
perhaps our modern word molecules would 
more correctly represent what ,reis     
spoke of as atoms7 of the rod or needle 
were pushed asunder from one another in 
the act of magnetisation1 and that on   
the cessation of the magnetising        
influence of the current1 these same    
atoms strove to return to their previous
 position of equilibrium1 and thus the  
oscillations of the atoms led to the    

vibration of the needle as a whole4     
,whether all ,reis's speculations as to 
the behaviour of the atoms under varying
 degrees of magnetising force are       
justified in the present aspect of      
science or not1 is1 however1 not of any 
great importance2 the important point   
is1 that1 whether his theory be right or
 wrong1 the instrument he devised will  
perform the function he assigned to it3 
it will reproduce speech1 not loudly1   
but in reality far more articulately    
than many of the telephonic receivers in
 use under the names of ,bell1          
,gower-,bell1 c4  ,one very curious     
point in connection with this           
8knitting-needle0 receiver of ,reis1 is 
its extremely bad acoustical            
arrangements4 ,it was laid horizontally 
upon a small sounding-box covered by a  
lid4 ,if the end of the needle had been 
made to press on the resonant-board 7as 
indeed appears to have been done at     
first with the violin1 p4 #bi7 the      
vibrations would have been much more    

directly reinforced4 ,but when merely   
supported by two wooden bridges the     
direct communication was largely lost4  
,the pressure of the lid downwards upon 
the spiral1 as recommended by ,reis1 is 
no doubt an important matter            
acoustically4 ,it is strange that a man 
who had grappled in so masterly a way   
with the acoustical problem of the      
transmitter1 and had solved it by       
constructing that transmitter on the    
lines of the human ear1 should not have 
followed out to the same extent those   
very same principles in the construction
 of his receiver4 ,an extended surface  
he did employ1 in the shape of a        
sounding-board2 but it was not applied  
in the very best manner in this         
instrument4  ,the second principle      
applied by ,reis in the construction of 
his telephone-receivers1 was that of the
 electro-magnet4 ,he arranged an        
electro-magnet so that the fluctuating  
currents passing round the coils set up 
corresponding variations in the degree  

of force with which it attracted its    
armature of iron1 and so forced the     
latter to execute corresponding         
mechanical vibrations4 ,this principle  
is common both to the receiver of ,reis1
 and to the later receivers of ,yeates1 
,bell1 and ,edison4 ,reis's armature was
 an iron bar of oval section2 ,yeates's 
an iron strip screwed to a sound-board1 
,bell's was an iron plate1 and ,edison's
 an iron plate also4  ,for the better   
comparison of ,reis's electro-magnetic  
receiver with those of more modern date1
 we here present in ,fig4 #df a         
comparative view of a number of         
different forms of receiver in which    
,reis's principle of causing an         
electro-magnet to set up vibrations in  
an armature is applied4 ,in this set of 
figures1 ,a and ,b are the suggested    
forms mentioned in the letter of ,mr4   
,horkheimer1 p4 #aai1 and show an       
electro-magnet1 opposite the poles of   
which is placed an armature 7a bar7     
which must be of iron or other metal    

capable of having magnetism induced in  
it1 and which1 by reason of its         
attachment to an elastic spring1 is     
capable of being made to oscillate to   
and fro when attracted with a varying   
force4 ,reis clearly recognised the     
necessity of further providing a        
sufficient resounding surface by means  
of which the surrounding air could be   
set in motion3 for in the case of these 
two suggestions the electro-magnet and  
its elastically-mounted armature were   
placed within a cigar box4 ,c is a plan 
of the receiving instrument previously  
described and figured in ,plate ,,ii4   
and in figures #ba and #cd on pages #cb 
and #aji4 ,in this instrument the       
electro-magnet was horizontal1 the      
armature1 a bar of iron of oval section 
7which in the original drawing in plate 
,,ii4 appears to have been in reality a 
hollow bar or tube7 attached to a thin  
lever described as a plank1 pivoted like
 a pendulum to an upright support1 but  
prevented by a set-screw and a          

controlling spring from vibrating in the
 manner of a pendulum4 ,such an         
arrangement1 in fact1 vibrates in       
perfect correspondence with any         
vibrations that may be forced upon it by
 the electro-magnet4 ,the broad flat    
surface of the lever--he specially      
directed that it should be broad and    
light--transfers the vibrations to the  
air1 and is aided by the surface of the 
sounding-board on which the apparatus   
stands4 ,this apparatus has1 therefore1 
all the elements of a successful        
receiver1 except only that its shape    
renders it inconvenient for portability4
 ,but by reason1 firstly of its armature
 of iron1 secondly of the elastic       
mounting of that armature1 thirdly of   
the extended surface presented1 it is   
admirably adapted to serve as an        
instrument for reproducing speech4      
,illustration3 ,fig4 #df4  ,fig4 #df ,d 
represents the excellent                
electro-magnetic receiver devised in    
#ahfe by ,yeates 7compare ,fig4 #db1 p4 

#abh7 to work with the ,reis            
transmitter1 and is in many respects    
identical with the preceding form4 ,the 
armature1 a strip of iron1 was attached 
at one end by a very stiff steel spring 
to a pine-wood sounding-board over a    
hollow box1 from the base of which rose 
the metal pillar which supported the    
electro-magnet4 ,this receiver also     
contains all the elements of a          
successful receiver1 the armature being 
of a material capable of inductive      
action1 and elastically supported2      
whilst the sound-box provided adequate  
surface to communicate the vibrations to
 the air4  ,we now come to the more     
modern instruments of ,gray1 ,bell1 and 
,edison4 ,so far the receivers of ,reis 
and of ,yeates were intended for        
reproducing any sound2 but now for the  
first time1 ten years after the date of 
these early telephonic receivers1 we    
meet with instruments devised with the  
express purpose of receiving only       
certain selected tones4  ,for the       

purposes of multiple acoustic           
telegraphy1 that is to say for the      
purpose of signalling the 8dots0 and    
8dashes0 of the ,morse code in a number 
of different fixed musical notes1 each  
of which is to be signalled out and     
repeated by a receiver adapted to       
vibrate in that note alone1 it is clear 
that the instruments of ,reis1 adapted  
as they were to transmit and receive any
 sound that a human ear can hear1 would 
not answer4 ,accordingly those          
experimenters1 who from about the year  
#ahgc to the year #ahgj1 applied        
themselves to multiple                  
telegraphy--foremost amongst them being 
,mr4 ,elisha ,gray and ,prof4 ,graham   
,bell--dropped the use of the tympanum  
in the transmitter and devised new      
transmitters and new receivers1 in most 
of which the ruling idea was that of    
employing a vibrating tongue or reed1   
tuned up to one particular note4 ,now it
 is obvious that a receiver which1 like 
those of ,reis1 is adapted to receive   

any tone1 can also receive a musical    
note4 ,but for the operation of         
8selective0 reception1 a receiver must  
be employed1 not only tuned to one note1
 but tuned to the very note emitted by  
the particular transmitter with which it
 is to be in correspondence4 ,elisha    
,gray found this out very early in his  
researches4 ,in the winter of #ahgc-ddi 
he was transmitting musical tones by a  
sort of tuning-fork interruptor1 and    
received them on an instrument shown in 
,fig4 #df ,e1 which represents a form of
 electro-magnet mounted for the purpose4
 ,it was 8a common electro-magnet1      
having a bar of iron rigidly fixed at   
one pole1 which extends across the other
 pole1 but does not touch it by about   
one sixty-fourth part of an inch4 ,in   
the middle of this armature a short post
 is fastened1 and the whole is mounted  
on a box made of thin pine1 with        
openings for acoustic effects40 ,it was1
 in fact1 very similar to ,yeates's     
receiver just described1 and ,gray found

 it capable of receiving not only simple
 musical tones but composite tones1 and 
even harmonies and discords4 ,in fact1  
like ,reis's and ,yeates's receivers1 it
 could receive anything that the        
transmitter sent to it1 even including  
speech4 ,now this did not suit ,gray1   
who wished to have selective receivers1 
one to take up note ,a1 another note ,c1
 c4 ,accordingly in #ahgj we find ,gray 
taking out a fresh patent#ej for        
selective receivers1 which he also      
called harmonic analysers1 each of which
 consisted of 8a tuned bar or reed      
suitably attached to an electro-magnet1 
and the whole mounted upon a resonant   
box40 ,fig4 #df ,f is reproduced from   
,gray's ,british patent4 8,a vibrating  
tongue reed1 or bar0 of steel 8is united
 with one pole of the magnet4 ,the free 
end of the reed passes close to1 but    
does not touch the other pole of the    
magnet40 ,gray further says that the    
reed is made with parallel sides and    
tuned by cutting it away at one point1  

as this mode prevents false nodal       
vibrations from occurring4  ,selective  
receivers for multiple telegraphy were  
also invented by ,graham ,bell4 ,the    
form shown in ,fig4 #df ,i is           
transcribed from ,fig4 #ae of ,bell's   
,specification to his ,british ,patent1 
,no4 #dgfe1 of the year #ahgf 7dated    
#ith ,december71 which the inventor thus
 describes3 8,it is preferable to employ
 for this purpose an electro-magnet ,e1 
,fig4 #ae1 having a coil upon only one  
of its legs4 ,a steel spring armature ,a
 is firmly clamped by one extremity to  
the uncovered leg h of the magnet1 and  
its free end is allowed to project above
 the pole of the covered leg40 ,in fact 
the arrangement was almost identical    
with1 but not quite as good mechanically
 as that patented seven months          
previously by ,gray4 ,the inventor      
further said that a number of these     
instruments might be placed on one      
circuit1 and that if one of them were   
set in vibration1 only those would      

respond which were in unison with its   
note2 and further that 8the duration of 
the sound may be used to indicate the   
dot or dash of the ,morse alphabet1 and 
thus a telegraphic despatch may be      
indicated by alternately interrupting   
and renewing the sound40  ,anything more
 totally different from ,reis's         
telephone than these selective harmonic 
telegraphs with their tuned tongues can 
hardly be imagined4 ,reis was not aiming
 at selective harmonic telegraphy2 he   
wanted his one instrument to transmit   
every sound that a human ear could hear4
 ,he did not dream of using a tuned bar 
or reed2 his typical structure was the  
tympanum of the ear4 ,in fact1 as we    
have seen above1 the tuned reed or      
tongue was introduced into telegraphy   
for the purpose of transmitting single  
selected notes to the exclusion of all  
others4  ,strange though it may seem1 a 
tongue receiver like those of ,graham   
,bell and of ,gray just described can be
 used for receiving speech6 ,it is true1

 as ,gray remarks1 that a thick bar of  
steel1 cut away as described1 is best   
adapted for its own tone only4 ,but     
,bell's thin steel tongue1 though it has
 its own fundamental note 7and so has   
every tympanum1 for that matter7 when   
left free to vibrate in its own time1   
will reproduce any other note or sound  
that may be forced upon it by the       
varying attraction of the               
electro-magnet4 ,there is1 indeed1 the  
whole difference between 8free0 and     
8forced0 vibrations4 ,one of the        
strangest delusions that has somehow    
grown up in recent telephonic           
discussions is the almost incredible    
proposition that a tongue cannot talk   
because it is a tongue4 ,it would be    
equally veracious to affirm that an ear 
7i4e4 a tympanum7 cannot hear because it
 is an ear4  ,but leaving harmonic      
telegraphy and its 8tuned bars10 both   
,gray and ,bell applied themselves to   
the old problem of transmitting human   
speech4 ,what was their very first step8

 ,they threw away their 8tuned bars0 and
 8steel springs10 and returned to the   
tympanum6 ,elisha ,gray devised the     
receiver shown in ,fig4 #df1 ,g1 taken  
from his caveat of date ,february #ad1  
#ahgf4ea ,in that document ,gray says3  
8,my present belief is that the most    
effective method of providing an        
apparatus capable of responding to the  
various tones of the human voice1 is a  
tympanum1 drum1 or diaphragm10 stretched
 across one end of a chamber4 ,he adds  
that in the receiver there is 7see ,fig4
 #df1 ,g7 an electro-magnet1 acting upon
 a diaphragm to which is attached a     
piece of soft iron1 and which diaphragm 
is stretched across a vocalising        
chamber4  ,graham ,bell's receiver 7the 
,american specification of which was    
filed the same day as ,gray's caveat7 is
 shown 7in the form patented in ,great  
,britain1 ,dec4 #i1 #ahgf7 in ,fig4 #df 
,h1 which is taken from ,fig4 #ai of    
,bell's ,british patent4 8,the          
armature10 says the inventor1 8is       

fastened loosely by one extremity to the
 uncovered leg1 h1 of the electro-magnet
 ,e1 and its other extremity is attached
 to the centre of a stretched membrane40
 ,the armature1 in fact1 was capable of 
vibrating like a pendulum on its pivot1 
but was elastically restrained by its   
attachment to the tympanum2 the armature
 would therefore vibrate in perfect     
correspondence with any vibrations      
forced upon it by the electro-magnet4   
,this instrument as also that of ,gray1 
was admirably adapted to receive speech1
 for it embodied the three essential    
points which ,reis had already          
discovered3 viz41 firstly1 that the     
armature must be of iron1 or capable of 
being acted upon by magnetic induction2 
secondly1 that it must be elastically   
mounted2 thirdly1 that it should present
 an extended surface4 ,bell's form of   
receiver had the advantage over ,reis's 
7compare p4 #aeh71 that its extended    
surface was a true tympanum of membrane1
 and not a mere broad thin plank4 ,being

 a tympanum1 it therefore realised      
,reis's fundamental notion of imitating 
the human ear more fully than even      
,reis's own receiver did4  ,figures #df1
 ,j1 ,k1 and ,l represent the more      
recent types of receiver of ,bell and   
,edison4 ,fig4 #df ,j is reproduced from
 ,fig4 #bj of ,bell's ,british ,patent1 
and shows the substitution of a thin    
steel plate1 attached to a frame1 in    
front of the electro-magnet1 for the    
membrane and iron armature4 ,this form  
of instrument also embodies ,reis's     
three principles--but with this         
improvement1 the armature capable of    
inductive action1 the elastic mounting1 
and the extended surface1 are here all  
united in one organ1 the thin flexible  
tympanum of steel4 ,apart from this     
unification of parts there is absolutely
 nothing in this form of ,bell's        
receiver1 that ,reis did not invent     
fourteen years before4 ,bell's great and
 most signal improvement was not this   
beautiful mechanical modification of the

 ,reis receiver1 but lay in the entirely
 new suggestion to use such a receiver  
as a transmitter to work by             
magneto-electric induction4 ,two of     
,reis's receivers 7,fig4 #ba7 if coupled
 up with a battery will talk together as
 transmitter and receiver3 but ,reis did
 not know and never suggested this4 ,two
 of ,yeates's receivers 7,fig4 #db7 if  
coupled up with a battery will talk     
together as transmitter and receiver2   
but ,yeates did not know and never      
suggested this4 ,bell did discover this1
 and thereby invented a transmitter     
which1 though now abandoned as a        
transmitter1 for want of loudness1 was  
more reliable than the anterior         
transmitters of ,reis had been4 ,he made
 another discovery1 presently to be     
alluded to--that of putting a permanent 
magnet into the transmitter1 to enable  
him to dispense with the battery2 but   
beyond this and the other mechanical    
simplifications previously mentioned1   
all that he discovered may be summed up 

by saying that he found out that a      
receiver constructed on ,reis's         
principles could work as a transmitter  
also4 ,that was ,bell's really great and
 important discovery which took all the 
world by storm at the ,centennial       
,exhibition of #ahgf4  ,bell            
subsequently added to his claims the    
substitution of a permanent magnet with 
an iron pole-piece1 in place of the     
simple electro-magnet1 thus enabling him
 to transmit his fluctuating currents   
without the trouble of using a battery1 
and the ,bell transmitter1 thus         
modified1 is used to this day as a      
receiver1 ,reis had in his              
8knitting-needle0 telephone1 employed a 
permanent magnet of steel to serve as a 
receiver1 he had not1 however1 applied  
it as ,bell did to attract a plate of   
thin steel4  ,fig4 #df1 ,k1 exhibits a  
form of electro-magnetic receiver       
described in ,edison's ,british         
,specification1 ,no4 #biji1 #ahgg1 ,fig4
 #bd4 ,this instrument1 though patented 

seven months after ,bell's instrument1  
differs from it in no point of          
importance4 ,its armature was a thin    
plate of iron1 elastic1 and having an   
extended surface2 being1 in fact1 a     
tympanum4  ,no one can examine the set  
of receiving instruments collected in   
,fig4 #df without being struck with the 
extraordinary similarity of design which
 pervades the entire series4 ,in every  
one of the set there is an              
electro-magnet1 the function of which is
 to set an armature#eb into vibration by
 attracting it with a variable force4   
,in every one the armature is of a      
material capable of magnetic induction2 
that is to say1 iron1 steel1 or         
equivalent material4 ,in every one of   
them the armature is either elastically 
mounted1 or is in itself elastic4 ,in   
every one of them 7save only the two    
quite recent forms1 ,f and ,i1 which    
were intended not to speak1 but to emit 
only one fixed musical note7 there is an
 extended surface 7either a sound-board 

or a tympanum7 to communicate the       
vibrations to the air4 ,lastly1 every   
one of these forms1 when connected with 
the line through which the telephonic   
currents are being transmitted1 is      
perfectly capable of reproducing        
articulate speech4 ,but the inventor who
 had the genius to discover all these   
essential points1 and to combine them in
 an instrument1 and to use it to        
reproduce articulate speech1 is surely  
the true inventor of the system4 ,the   
inventor of the system embodying these  
essential points was ,philipp ,reis4    
,,footnotes3  #di ,see ,prescott's      
#8,speaking ,telephone1' p4 #aeh4  #ej  
#8,british ,patent1' ,no4 #ahgd1 of the 
year #ahgf 7dated #dth ,may74  #ea      
,prescott1 #8,speaking ,telephone1' p4  
#bjc4  #eb ,yet ,bell's claim 7,british 
,patent ,specification7 runs3 8,i claim 
the production of any given sound or    
sounds from the armature of the         
receiving instrument40     ,,appendix   
,,iv4  ,,on ,,the ,,doctrine ,,of       

,,undulatory ,,currents4      8,in this 
,specification the three words          
#8oscillation1'     #8vibration' and    
#8undulation1' are used                 
synonymously40--,graham     ,bell1      
,u4,s4 ,patent1 ,no4 #agd1dfe1 filed    
,feb4 #ad1 #ahgf4   ,in the preceding   
appendices it has been demonstrated that
 all that is essential in both          
transmitter and receiver of a           
,telephonic system was to be found      
existing in #ahfc in the ,telephone of  
,reis4 ,there yet remains to be met the 
doctrinaire objection that as ,reis     
never explicitly mentions an undulatory 
current as distinguished from an        
intermittent one1 he never intended to  
use such a current4 ,this objection is  
advanced only by those persons who have 
committed themselves to the idea that   
speech cannot be transmitted by a       
transmitter which opens and closes the  
circuit4  ,it is certain that ,reis did 
not in any of his writings explicitly   
name an undulatory current3 but it is   

equally certain that1 whether he        
mentioned it or not1 he both used one   
and intended to use one4 ,he did not    
concern himself as to the precise manner
 in which the current fluctuated        
provided only he attained the end in    
view--namely1 that the vibrations of the
 armature of the receiver should be     
similar to those of the transmitter4    
,this he did lay down with great        
clearness and emphasis as his guiding   
principle2 and he cared not about the   
intermediate question as to how the     
current did the work4 ,he told the world
 that the electromagnet at the receiving
 end must be magnetised and demagnetised
 correspondingly with the vibrations    
imparted by the air to the tympanum of  
his transmitter1 in order that the      
armature might be set into vibrations   
similar to those of the speaker's voice4
 ,if the tympanum of the transmitter    
vibrated or oscillated or undulated--the
 terms are synonymous--so must the      
armature of the receiver4 ,graham ,bell 

has told us precisely the same thing3   
8,the current traversing the coils of   
the electromagnet ,e occasions an       
increase and diminution in its          
intensity0 that is to say1 magnetises   
and demagnetises it1 8and the armature  
,a#a is thrown into vibration0 444 8and 
thus imparts to the air at n#a a        
facsimile copy of the motion of the air 
that acted upon the membrane n40 ,bell  
agrees then absolutely in every detail  
with what ,reis said on this point4     
,that sound-waves should be transmitted 
by a ,telephone requires indeed a       
process of several stages4 7#a47 ,the   
sound-waves must strike upon the        
tympanum of the transmitter and make it 
undulate1 or1 oscillate1 or             
vibrate--whichever term you please--in a
 corresponding manner4 7#b47 ,the       
undulating tympanum must act upon the   
circuit1 and either itself induce       
undulating or vibrating currents        
7,bell's plan1 by magnetic induction71  
or else throw a current already flowing 

there1 into undulations1 or vibrations1 
or oscillations 7,reis's plan1 by       
varying contact-resistance71 but in     
either case these undulations of the    
current must correspond to the original 
undulations of the air-waves4 7#c47 ,the
 undulating1 or vibrating1 or           
oscillating current must run round the  
coils of the electromagnet and cause its
 magnetic force to undulate1 or         
oscillate1 or vibrate by demagnetising  
it and then magnetising it1 but this    
also must be in a manner corresponding  
to the original undulations4 7#d47      
,further1 the armature of the receiver  
must be set into undulations1 or        
vibrations1 or oscillations             
corresponding to those of the force of  
the electromagnet1 and therefore to the 
undulations of the current that is      
magnetising and demagnetising it1 and   
therefore identically corresponding with
 the original undulations of the        
sound-waves4 7#e47 ,the armature must   
communicate its vibrations to the air   

and to the ear of the listener4 ,of     
these successive stages ,reis explicitly
 told the world that his instrument was 
to do the first one and the last three1 
and he several times emphasized the     
statement1 that the final undulations of
 the last stage were to be similar to   
the original undulations of the first   
stage4 ,the air at the listening end1   
the armature of the receiver1 and the   
magnetism of the magnet1 were all to be 
set by the fluctuations of the current  
into undulations corresponding with     
those of the tympanum at the speaker's  
end1 and of the waves of his voice4 ,it 
is perfectly clear therefore1 that he   
regarded as self-evident the            
intermediate stage1 and he did not dwell
 upon the necessity of the point1 that  
his transmitting-current must also      
vibrate1 because this was obviously so1 
and was only an intermediate matter of  
secondary moment4 ,he chose rather to   
point out the necessity of unification  
between the first and last stages1      

leaving it to common sense to see that  
the 8interruption0 or the 8opening and  
closing0 of the circuit must be effected
 in a manner corresponding to the       
undulations of the impressed sound-wave4
 ,had the 8interruptions0 not been of   
the nature of corresponding variations  
of contact1 the current could not have  
been set into corresponding vibrations1 
and the armature of the electromagnet   
could not have reproduced the vibrations
 of the transmitter4 ,clearly ,reis's   
whole conception of telephony included  
as a minor and intermediate step the    
fact that the current was1 by the action
 of the transmitter1 caused to vary in  
strength in correspondence with the     
undulations of the tympanum--that1 in   
fact1 it was made to undulate by the    
action of the tympanum and of the       
interruptor which opened and closed the 
circuit in obedience to the undulations 
of the tympanum and in proportion to    
them4  ,a difficulty has been raised by 
telegraph operators that opening and    

closing the circuit means opening and   
closing the circuit in abrupt           
alternations of make-and-break4 ,reis   
never said so4 ,reis never used the     
phrase in this restricted and technical 
sense4 ,he was not a professional       
telegraphist1 and1 as pointed out in    
,appendix ,i41 he so arranged his       
contacts with the following springs and 
other contrivances1 that the 8opening   
and closing0 of the circuit should not  
and could not be abrupt4 ,a ,reis       
transmitter is no more a                
8make-and-break0 instrument than the    
,blake transmitter is4 ,both will give  
undulatory currents by opening and      
closing the circuit to a greater or less
 degree1 if spoken gently to4 ,both will
 give abrupt makes-and-breaks of the    
circuit if shouted to1 in spite of the  
following-springs1 which are used to    
prevent abrupt interruptions4 ,the term 
8opening and closing0 which ,reis       
applied to his transmitter1 is used by  
him in exactly the same way as the      

phrase is used by engineers in          
describing the action of the governing  
throttle-valve of a steam-engine4 ,the  
function of the governor1 we are told in
 treatises on engineering1 is to open   
and close the throttle-valve in a manner
 corresponding to the fall or rise of   
the governor-balls4 ,no one in his      
senses imagines that the opening and    
closing action here referred to means an
 absolutely abrupt intermittence in the 
supply of steam4 ,if the governor-balls 
rise a little by increase of speed1     
there is a corresponding closing1       
proportionate in amount to the amount of
 rise4 ,if any person were to impress an
 oscillatory motion of rise and fall    
upon the governor1 the supply of steam  
would be thrown into corresponding      
undulations4 ,the matter stands         
precisely so with ,reis's 8interruptor0 
or 8regulator20 it opens and closes the 
circuit in a manner corresponding with  
the undulations communicated to it4 ,if 
it did not1 it would violate the        

principle of correspondence so          
emphatically laid down by ,reis4  ,it   
is1 however1 true that ,reis's          
instruments1 in spite of springs and    
adjusting screws1 and other devices to  
prevent abrupt make-and-break occurring1
 were prone1 by reason of the very      
lightness of the parts1 to break        
contact1 if too loudly spoken to4 ,they 
share this fault with the more perfect  
transmitters of ,blake and ,berliner    
which are used to-day so generally4 ,the
 undulatory currents of these           
transmitters are1 like those of ,reis's 
transmitters1 liable to an occasional   
abrupt interruption1 which1 though it   
may not seriously affect the            
intelligibility of the words1 does1 to  
some extent1 mar the perfection of the  
articulation4 ,still1 in practice1 to   
judge by the instruments used in the    
telephone exchanges of ,great ,britain1 
the ,blake transmitter with its         
liability to make-and-brake abruptly is 
a more satisfactory instrument than the 

,bell transmitter1 which is not used at 
all4 ,now the ,bell transmitter working 
on the principle of which ,bell is the  
first and undisputed inventor1 is one in
 which the degree of contact in the     
circuit is never changed3 for it works  
by the principle of 8induction10 whereby
 currents are set up in a circuit that  
is never opened or closed1 either       
partially or wholly4 ,nevertheless the  
,blake transmitter1 which opens and     
closes the circuit in proportion to the 
undulations of the tympanum1 is the more
 satisfactory instrument for producing  
the undulating currents required to     
procure the all-essential correspondence
 between the undulations of the tympanum
 of the transmitter and those of the    
armature of the receiver4 ,to sum the   
matter up1 it appears that an instrument
 which opens and closes the circuit on  
,reis's principle of transmitting is in 
practice a more satisfactory transmitter
 of undulatory currents than ,bell's    
transmitter which cannot open or close  

the circuit in the least4 ,reis1 with   
his instruments1 transmitted speech--as 
,herr ,hold tells us 7p4 #abf7--when the
 words spoken were not too loud4 ,that  
is a proof that he did really use1      
whether he knew it or not1 undulatory   
currents of electricity3 and an         
undulatory current is none the less an  
undulatory current1 even if occasionally
 abruptly interrupted4 ,a speech is none
 the less a speech1 even if the orator  
sneeze once or twice while speaking4    
,nay1 we may go further1 and say that an
 undulatory current is an undulatory    
current1 even though the finer ripples  
of the waves are lost in transmission4  
,this is what seems to have been the    
case with ,reis's instruments as they   
were in #ahfa and #ahfb4 ,the consonants
 were satisfactorily transmitted1 and so
 were all musical tones within the range
 of the instrument4 ,but the finer      
ripples of the vowels were lost somehow 
in transmission4 ,reis1 whose innate    
honour and modesty led him always rather

 to understate than overstate the facts1
 most frankly acknowledged this1 nay    
even invited attention to the fact1 and 
discussed the imperfection from a high  
scientific standpoint4 ,he proposed to  
rely for the correctness of his views   
upon the actual recorded curves of      
sound-waves1 as taken down automatically
 by the then newly-invented             
phonautograph of ,scott 7see p4 #fj74   
,it is perfectly marvellous how precise 
his views were upon the correspondence  
between the graphic curve or wave-form  
of a sound and the actual sound itself2 
a precision amply justified by the      
experience and the discoveries of the   
last ten years4  ,this matter of        
representing sounds--or rather the      
varying density of the air in the       
sound-wave--by a graphic curve1 was a   
vital one to ,reis4 ,had he had a less  
clear view of the nature of sound-waves 
than that afforded by a graphic curve1  
,i doubt whether he would ever have     
grasped the problem of the              

telephone--that the final vibrations1 or
 undulations1 or oscillations of the    
armature in the receiver must correspond
 with--must be the very counterpart     
of--those of the tympanum of the        
transmitter4 ,the clearness with which  
,reis saw this is only surpassed by the 
clearness with which he expressed       
himself upon it4 ,for him a sound was   
simply a complicated series of          
variations in the density of the air1   
and capable1 in all its complexity1 of  
being represented by the rise and fall  
of an undulatory curve4 8,every tone1   
and every combination of tones1 evokes  
in our ear vibrations 444 the motions of
 which may be represented by a curve0   
7p4 #ed74 8,that which is perceived by  
the auditory nerve 444 may be           
represented graphically according to its
 duration and magnitude by a curve0 444 
7p4 #ec74 8,our ear can perceive        
absolutely nothing more than is capable 
of being represented by similar curves0 
7p4 #ec74 ,the curves with which he     

accompanied his original memoir--and now
 reproduced in facsimile1 from ,legat's 
plates1 at the end of this volume--are  
evidence of the thoroughness of his     
grasp on the undulatory principle4 ,and 
he explicitly states this principle     
amongst 8the various requisite          
conditions which must be fulfilled by   
the transmitting and receiving apparatus
 for the solution of the problem that   
has been set0 7,legat's ,report1 p4     
#ga74 ,he declared that so soon as it   
should become possible 8at any place1   
and in any prescribed manner0 7that is  
to say1 whether by electric undulations 
or by mechanical undulations1 as in the 
string of the toy telephone1 or by any  
other means71 8to set up vibrations     
whose curves are like those of any given
 tone or combination of tones10 we      
should then receive the same impression 
as that tone or combination of tones    
would have produced upon us4  ,so much  
for ,reis's principle of correspondence 
of undulations between the transmitter  

and the receiver2 we have seen how clear
 and precise1 yet how comprehensive it  
was1 and how the general proposition    
necessarily included within itself1 as  
an intermediate step1 the particular    
minor proposition that the undulations  
of the current must also be in          
correspondence with the voice4  ,keeping
 these points in mind1 it is very       
remarkable that when ,graham ,bell1     
fourteen years later1 followed ,reis    
8into the field of telephonic research10
 he selected the very same method of    
expressing the relations between sounds 
and the undulations which corresponded  
with them4 ,to show how remarkably in   
agreement the views of ,reis and ,bell  
are upon this question of representing  
by a curve the undulations which        
correspond to the voice1 we select the  
following paragraphs and place them in  
parallel columns4      ,reis4      ,that
 which is perceived by     the auditory 
nerve 444 may     be represented        
graphically1     according to its       

duration and     magnitude by a         
curve4--7,memoir     #8,on ,telephony'  
in the     ,jahresbericht of the        
,physical     ,society of               
,frankfurt-a4-,m4     #ahfj-fa1 p4 #ei47
 p4 #ec4      ,the height or depth of   
the sound produced 444     depends upon 
the number of     vibrations made in a  
given     time4--7,ib4 p4 #fc47 p4 #ei4 
,bell4          ,electrical undulations1
 induced         by a body capable of   
inductive action1 can be represented    
graphically1 without         error by   
the same sinusoidal         curve which 
expresses the vibration         of the  
inducing body         itself1 and the   
effect of its vibration         upon the
 air2 for1 as         stated above1 the 
rate of oscillation         in the      
electrical current         corresponds  
to the rate of vibration         of the 
inducing body--that         is1 to the  
pitch of the         sound              
produced4--7,specification         of   
,u4 ,s4 ,patent ,no4         #agd1dfe1  

dated ,march #g1 #ahgf47      ,reis4    
,the greater the condensation     of the
 sound-conducting     medium at any     
given moment1     the greater will be   
the amplitude     of vibration of the   
membrane4--7,ib4     p4 #eh47 p4 #eb4   
,bell4          ,the intensity of the   
current         varies with the         
amplitude of         the vibration--that
 is1 with         the loudness of the   
sound2--7,ib47      ,reis4      444 each
 tone is dependent     not only on the  
number of     vibrations of the medium1 
but     also on the condensation or     
rarefaction of the same4--7,legat's     
,report1 ,zeitschrift des               
,d4-,oesterr4 ,telegr4 ,vereins1        
#ahfc1 p4 #abe47 p4 #gg4          ,bell4
          and the polarity of the       
current         corresponds to the      
direction of         the vibrating      
body1--that is1         to the          
condensations and         rarefactions  
of air produced         by the          
vibration4--7,ib47      ,reis4      ,let

 us exhibit the condensation     curves 
for three tones--each     singly 7,plate
 ,i73 then1     by adding together the  
ordinates     corresponding to equal    
absciss1 we can determine     new       
ordinates and develop a     new curve   
which we may call     the               
combination-curve4 ,now     this gives  
us just exactly what     our ear        
perceives from the     three            
simultaneous tones4--7,memoir     #8,on 
,telephony1'     p4 #ei47 p4 #ed4       
,bell4          ,the combined effect of 
,a         and ,b1 when induced         
simultaneously         on the same      
circuit1         is expressed by the    
curve         ,a  ,b1 ,fig4 #d1 which is
 the         algebraical sum of the     
sinusoidal         curves ,a and ,b4    
,this         curve ,a  ,b also         
indicates the         actual motion of  
the air when         two musical notes  
considered         are sounded          
simultaneously4444         7,ib47 ,the  
electrical movement1 like the           

aerial motion1 can be represented       
by a sinusoidal curve1 or         by the
 resultant of several         sinusoidal
 curves4--7,ib47  ,the very remarkable  
agreement of the preceding passages     
receives a most striking confirmation by
 comparing the curves respectively drawn
 by ,reis and by ,bell4 ,these are      
facsimiled below1 ,reis's               
8combination0-curve 7,fig4 #dg7 from    
,plate ,i4 of his ,memoir 7also ,plate  
,i4 of this volume71 and ,bell's        
8resultant0-curve 7,fig4 #dh7 from ,fig4
 #d of his ,united ,states ,patent      
,specification ,no4 #agd1dfe4  ,the most
 casual observer cannot fail to notice  
here that the three lines of undulatory 
curves of ,bell's specification are     
practically identical with the three    
lower lines of undulatory curves of     
,reis's memoir4 ,they are1 moreover1 in 
each case introduced for the sake of    
showing how a complex curve corresponds 
to a compound undulation4  ,reis44      
,illustration3 ,fig4 #dg4  ,bell44      

,illustration3 ,fig4 #dh4  ,far be it   
from me even to hint that either curve  
was plagiarised from the other4 ,bell   
tells us that his curve is to represent 
electrical oscillations1 which1 he adds1
 have the same curve as that both of the
 vibrating body and of the air4 ,reis   
tells us that his curve is to represent 
the oscillations of a tympanum1 or of   
the air1 or of the magnetisation of the 
magnet1 or of the armature at the       
receiving end4 ,how the magnetization of
 the electro-magnet was made to vary    
8correspondingly with the condensations 
and rarefactions of the air10 as        
represented by such a curve1 ,reis did  
not explicitly say1 but left to the     
common sense of his readers to infer4   
,though the inference was obvious1      
,bell1 who possibly had not then read   
,reis's researches1 seized upon this    
intermediate stage of the process       
employed by ,reis1 and probably quite   
unconscious that ,reis had already      
employed it1 announced it as a discovery

 of his own2 and then1 losing sight of  
the point that all that was wanted was  
to secure correspondence between the    
initial and final stage1 he magnified to
 an absurd and unwarranted importance   
this intermediate correspondence of the 
vibrations of the current with those of 
the tympanum1 which correspondence any  
one reading ,reis's papers would know at
 once ,reis had implicitly assumed and  
actually employed when he transmitted   
articulate speech4  ,if we pass from the
 method of graphically representing     
undulations by curves1 and proceed to   
compare the language in which ,reis     
described the action of his machine in  
reproducing the undulations imparted to 
the transmitter1 with that in which     
,graham ,bell described the action of   
his machine some fourteen years later1  
we shall find#ec an agreement even more 
precise4      ,reis4      ,the          
electromagnet 444     will be           
demagnetised and magnetised             
correspondingly with     the            

condensations and rarefactions     of   
the mass of air1 444 and     the        
armature 444 will be     set into       
vibrations similar to     those of the  
membrane in     the transmitting        
apparatus4--7,legat's     ,report1      
,zeitschrift1     p4 #abh1 #ahfb47 p4   
#gg4          ,bell4          ,the      
current traversing the         coils of 
the electromagnet ,e1         occasions 
an increase and diminution         in   
its intensity1 and the         armature 
,a#a is thrown into         vibrations  
444 and thus imparts         to the air 
at n#a a facsimile         copy of the  
motion of         the air that acted    
upon the         membrane               
n4--7,specification         of ,british 
,patent1 ,no4 #dgfe1         ,dec4 #ith1
 #ahgf1 p4 #ag47      ,reis4      ,the  
transmitter1 ,fig4 ,a1     consists of a
 conical tube 444     closed by a       
membrane 444 by     speaking 444 into   
the tube 444     there will be evoked a 
motion     of the membrane 444 7op4     

cit47          ,bell4          ,a cone  
,a is used to converge         sound    
vibrations upon         the membrane4   
,when a sound is uttered in         the 
cone the membrane a is         set in   
vibration4444      ,reis4      ,the     
apparatus 444 offers     the possibility
 of creating     these vibrations in    
every     fashion that may be desired1  
and the employment of electro-galvanism 
gives us the possibility     of calling 
into life1 at     any given distance1   
vibrations     similar to the vibrations
     that have been produced1 and     in
 this way to reproduce at any     place 
the tones that have been     originated 
at another place4--7,legat's            
,report1 op4 cit47          ,bell4      
444 and thus electrical undulations     
are created upon the         circuit ,e 
b e f g4444 ,the         undulatory     
current passing         through the     
electromagnet f         influences its  
armature h to         copy the motion of
 the armature         c4444 ,these      

undulations         are similar in form 
to the air undulations         caused by
 the sound4      ,reis4     ,as soon    
therefore as it shall     be possible   
444 to set up     vibrations whose      
curves are     like those of any given  
tone or     combination of tones1 we    
shall     receive the same impression   
as that tone or combination of     tones
 would have produced     upon           
us4--7,memoir #8,on ,telephony1'     p4 
#fj47 p4 #ee4          ,bell4           
--that is1 they are represented         
graphically by similar                  
curves4444          ,a similar sound to 
that         uttered into ,a is then    
heard to         proceed from           
,i4--7,specification         of ,u4 ,s4 
,patent1 ,no4 #agd1dfe47    ,reis4      
,any sound will be reproduced1   if     
strong enough to set   the membrane in  
motion4--7,letter   to ,mr4 ,ladd1      
#ahfc47   p4 #hd4          ,bell4       
,there are many other uses         to   
which these instruments         may be  

put1 such as 444 the         telegraphic
 transmission of         noises or      
sounds of any         kind4--7,ib47     
,i would have it understood         that
 what ,i claim is3--444         ,tenth4 
,in a system of         electric        
telegraph or telephony                  
consisting of transmitting and          
receiving instruments united            
upon an electric circuit1 ,i claim      
the production in the armature          
of each receiving instrument         of 
any given motion by subjecting          
said armature to an attraction          
varying in intensity1 however           
such variation may be         produced  
in the magnet1 and         hence ,i     
claim the production         of any     
given sound or         sounds from the  
armature         of the receiving       
instrument         by subjecting said   
armature         to an attraction       
varying         in intensity in such    
manner         as to throw the armature 
into that form of vibration         that

 characterizes the         given sound  
or sounds4--7,specification         of  
,british ,patent1         ,no4 #dgfe1   
,dec4 #i1 #ahgf47      ,reis4     the   
armature belonging to     the magnet    
will be set into     vibrations similar 
to those     of the membrane in the     
transmitting apparatus4--7,legat's      
,report1 #ahfb47 p4 #gg4  ,one cannot   
help thinking that some claims to great 
inventions are just a little 8too       
previous40  ,if it should still be said 
that ,reis's method of transmitting     
speech1 whether it did its work by      
undulatory currents or no1 was avowedly 
imperfect1 and that therefore such a    
claim as that quoted above is justified 
by the subsequent invention of an       
instrument the articulation of which was
 more reliable1 let us compare what each
 inventor has said about the            
imperfections#ed of his own instrument4 
,reis4      ,that which has here been   
spoken of will still require            
considerable improvement1     and in    

particular mechanical     science must  
complete the     apparatus to be        
used4--7,legat's     ,report1 #ahfb47 p4
 #gh4          ,bell4          ,it is a 
mistake1 however1 to         suppose    
that the articulation         was by any
 means perfect4444         ,still the   
articulation was there1         and ,i  
recognized the fact that         the    
indistinctness was entirely         due 
to the imperfection of the              
instrument4--7#8,researches in          
,telephony1' ,journal of ,soc4 of       
,telegr4 ,engineers1 ,dec4 #ahgg47  ,if 
it should be said that ,bell is here    
speaking only of an early and           
experimental form1 and not of his real  
invention1 it should be remembered that 
,bell here refers to the apparatus with 
cone and membrane1 identical with that  
exhibited at ,glasgow in ,september1    
#ahgf1 by ,sir ,william ,thomson 7who   
had received it from ,bell7 and by him  
described as the very 8hardihood of     
invention10 and 8by far the greatest of 

all the marvels of the electric         
telegraph40 ,it certainly worked upon   
the principle of undulatory currents1#ee
 whether it articulated or not4 ,bell   
had himself1 speaking in ,may #ahgf1    
before the ,american ,academy of ,arts  
and ,sciences upon his researches1 even 
more explicitly admitted the            
imperfections of his own instrument4    
,the effects were not sufficiently      
distinct to admit of         sustain ed 
conversation through         the wire4  
,indeed1 as a general         rule1 the 
articulation was         unintelligible1
 excepting         when familiar        
sentences were                          
employed4--7,proceedings of             
,american ,academy of ,arts         and 
,sciences1 vol4 xii4 p4 #g47  ,yet this 
most imperfect machine1 of which the    
articulation was1 as a general rule1    
unintelligible1 had1 two months         
previously1 had a patent granted to it  
as a new invention1 the claim being for 
8the method of1 and apparatus for1      

transmitting vocal or other sounds      
telegraphically1 as herein described1 by
 causing electrical undulations similar 
in form to the vibrations of the air    
accompanying the said vocal or other    
sounds1 substantially as set forth40    
,if then mere mechanical imperfections  
do not make an invention any the less a 
true invention capable of legal         
recognition1 it would be dishonest to   
the last degree to deny to ,philipp     
,reis the honour of his invention1 of   
which he honestly and openly stated both
 the successes and the imperfections4   
,he told the world what he aimed at1 and
 in what measure success had crowned his
 aims4 ,his claim to be the inventor of 
the ,telephone he considered to be      
justified by that measure of success4   
,if he was so far in advance of his time
 that the world was unprepared to       
receive or use the splendid discovery   
which he gave freely to it1 that was not
 his fault2 nor does neglect or apathy  
make him in one single degree the less  

entitled to the credit of his           
inventions4 ,tulit alter honores has not
 unfrequently been truly said concerning
 the men of genius who have had the     
misfortune to live in advance of the    
age4  ,but posterity does not let the   
names of such truly great ones perish in
 the dust4 ,the inventor of the         
,telephone will be remembered and       
honoured in the coming if not in the    
present age4  ,,schedule ,,of           
,,authorities    ,key to ,title of      
,work3    ,a4 #8,jahresbericht des      
,physikalischen ,vereins zu             
,frankfurt-am-,main'   ,b4              
#8,fortschritte der ,physik' 7,krnig and
 ,beetz7   ,c4 ,dingler's               
#8,polytechnisches ,journal'   ,d4      
#8,polytechnisches                      
,central-,blatt'7,schnedermann and      
,bttcher7   ,e4 ,bttger's               
#8,polytechnisches ,notizblatt'   ,f4   
#8,didaskalia'   ,g4 #8,zeitschrift des 
,deutsch-,oesterreichischen ,telegraphen
 ,vereins'      7,dr4 ,brix7   ,h4      

,kuhn's #8,handbuch der angewandten     
,elektricittslehre'   ,i4 ,pisko's      
#8,die ,neueren ,apparate der ,akustik' 
,j4 7,pisko's7 #8,hessler's ,lehrbuch   
der ,technischen ,physik'   ,k4 ,mller  
,pouillet's #8,lehrbuch der ,physik'    
----------------------------------------
------------------------     ,title     
,place of    ,date4     ,volume and     
,british       of ,work4   ,issue4      
,page4             ,museum4             
----------------------------------------
------------------------      ,a4       
,frankfurt  #ahfj-a  p4 #eg             
,ac4 #ddbh                  -a4-,m4     
#ahfc    p4 #abi                        
,b4      ,berlin     #ahfa    xvii4 p4  
#aga-agc    ,ac4 #cgge                  
#ahfc    ----8 p4 #if                   
,c4      ,stuttgart   #ahfc   clxviii4  
p4 #ahe-ahg ,pp4 #aghj                  
clxix4 p4 #bc                           
clxix4 p4 #cii                          
,d4      ,cassel      #ahfc    xxix4 p4 
#heh         ,pp4 #afae b4              

,e4      ,mainz       #ahfc   ,no4 #f   
,pp4 #aghg                              
,no4 #ae                                
,f4      ,frankfurt   #ahfb    ,may #h1 
,may #ad            44                  
-a4-,m4                                 
,g4      ,berlin      #ahfb    ix4 p4   
#abe               44                   
,h4      ,leipzig     #ahff    p4       
#ajag-ajba         #bbdd i              
,i4      ,vienna      #ahfe   p4 #id-ajc
           #hgje cc4                    
p4 #bda-bdc                             
,j4      ,vienna      #ahff    ,vol4 ,i4
 p4 #fdh           44                   
,k4      ,brunswick   #ahfh    ,vol4    
,,ii4 p4 #chf-chh      44               
----------------------------------------
------------------------   ,,and        
,,references4     ,key to references3   
#a4 ,royal ,society4   #b4 ,ronald's    
,library4   #c4 ,institution ,civil     
,engineers4   #d4 ,royal ,institution4  
#e4 ,great ,seal ,patent ,office4   #f4 
,school of ,mines4   #g4 ,university    

,college1 ,london4   #h4 ,bodleian      
,library1 ,oxford4   #i4 ,king's        
,college4   #aj4 ,oxford ,university    
,museum ,library4                       
----------------------------------------
----------------     ,title   #a4   #b4 
#c4   #d4    #e4   #f4  #g4     #h4     
#i4aj4    of ,work4                     
----------------------------------------
----------------      ,a4    #ahdf  44  
44  44     44   44 44     44     44 44  
-#ahfj                                  
,b4      x   44 x    x   #fedf1  x   x  
44     x  x                             
#aah ,e                                 
,c4      x   44 x    x   #abif1  x  44  
44     44 44                            
#id ,a                                  
,d4     44   44 44  44   #aacb1  44 44  
44     44 44                            
#id ,i                                  
,e4     44   44 44  44     44   44 44   
44     44 44                            
,f4     44   44 44  44     44   44 44   
44     44 44                            

,g4     44   44 x   44   #ieaa1  44 44  
44     44 44                            
#bd ,e                                  
,h4     44   x  44   x   #acadf1 44 44  
#aih e #acc 44 44                       
#afc ,c                                 
,i4      x   44 44  44     44   44 44   
44     44 x                             
,j4     44   x  44  44     44   44 44   
44     44 44                            
,i4     44   44 44,a newer  44   x 7,ed4
    44     44 x                         
edition         #ahgf7                  
7#ahgb7                                 
----------------------------------------
----------------   ,,footnotes3  #ec ,in
 making these comparisons in parallel   
columns1 ,i wish to repudiate in the    
most emphatic way any sinister inference
 that might be drawn as to ,graham      
,bell's use of descriptions and curves  
identical in so many points with those  
of ,reis4 ,for1 in the first place1 ,i  
believe ,professor ,bell to be incapable
 of such contemptible appropriations1   

and the candour with which he has       
himself invited comparison by giving    
various references to ,reis's papers1   
itself precludes such inference4 ,in the
 second place1 ,i do not think that at  
the date of these quotations ,bell      
understood ,german sufficiently well to 
comprehend ,reis's very precise         
statement of the problem of the         
,telephone4 ,i simply exhibit these     
parallel extracts to show the           
thoroughness with which ,reis had       
grappled with the problem with which1   
fourteen years later1 ,bell also        
grappled2 and to prove in the most      
irrefragable manner1 from the necessary 
identity in the terms selected for      
expressing the facts of the solution of 
the problem1 that the problem to which  
each found a solution was identical4    
,the circumstance that does1 however1   
puzzle me1 and which does not appear in 
these parallel extracts1 is that1 whilst
 in his original memoir1 ,reis speaks in
 detail of the auditory ossicles and    

their movements as having suggested his 
transmitter1 and casually mentions the  
phonautograph of ,scott in support of   
his views1 ,bell1 in his original       
lecture before the ,american ,academy1  
speaks in detail of ,scott's            
phonautograph as having suggested his   
transmitter1 and casually refers to the 
auditory ossicles and their movements4  
#ed ,reis's failures were chiefly with  
the vowels1 ,bell's more particularly   
with the consonants4 ,reis's contacts   
were liable to break1 and the           
following-springs of his                
contact-regulators too little pliable4  
,bell's transmitter could not open and  
close the circuit proportionally with   
the motions of the tympanum1 and owing  
to the sluggishness due to              
self-induction in the coils of his      
telephone1 the induced undulations of   
the current failed to come up in        
suddenness to those of the tympanum4 ,in
 consequence whip sounded like whim1 and
 kiss like kith1 even in the perfected  

,bell ,telephones made two years after  
,bell's first 8improvements0 in         
telephony were patented4  #ee ,the      
following very remarkable passage occurs
 in the evidence given by ,professor    
,graham ,bell concerning ,reis's        
,telephones4 7,see published volume of  
#8,proceedings in the ,united ,states   
,patent ,office before the ,commissioner
 of ,patents4' ,evidence for ,a4 ,g4    
,bell1 p4 #ad47  ,question #cg4 8,if a  
,reis ,telephone1 made in accordance    
with the descriptions published before  
the earliest dates of your invention1   
would in use transmit and receive       
articulate speech as perfectly as the   
instruments did which were used by you  
on ,june #be1 #ahgf1 at the ,centennial1
 would it be proof to you that such     
,reis's ,telephones operated by the use 
of undulatory movements of electricity  
in substantially the same way as your   
instruments did upon the occasion       
referred to80  ,answer by ,bell4 8,the  
supposition contained in the question   

cannot be supposed4 ,were the question  
put that if ,i were to hear an          
instrument give forth articulate speech 
transmitted electrically as perfectly as
 my instruments did on the occasion     
referred to in the question1 ,i would   
hold this as proof that the instrument  
had been operated by undulatory         
movements of electricity1 ,i would      
unhesitatingly answer1 ,yes40  ,surely  
no better authority is needed to support
 the proposition that if ,reis made his 
,telephone speak1 as he said he did1 he 
employed undulatory currents4           
,,additional ,,preferences ,,concerning 
,,reis',s ,,telephone4       ,schenk's  
,philipp ,reis1 der ,erfinder des       
,telephons1 #ahgh4      ,sack's ,die    
,entwickelung der elektrischen          
,telephonie1 #ahgh4      ,ferguson's    
,electricity 7,ed4 #ahfg71 p4 #beg4     
,wiedemann's ,galvanismus 7#ahgd71 ,vol4
 ii4 p4 #eih4      ,gartenlaube1 die2   
for #ahfc1 ,no4 #ea1 p4 #hjg-hji4       
,aus der ,natur2 for #ahfb1 xxi4 p4     

#dgj-dgd4      ,cosmos1 ,vol4 xxiv4 p4  
#cdi 7#ahfd74      ,proc4 ,lit4 ,phil4  
,soc4 ,manchester 7#ahfe71 ,nov4 #aj1   
#ahfd4      ,rep4 ,brit4 ,assoc4        
7#ahfc71 p4 #ai4      ,die ,geschichte  
und ,entwickelung des elektrischen      
,fernsprechwesens1 #ahhj4 7,officially  
issued from the ,imperial     ,german   
,post-,office1 ,berlin47       ,,london3
 ,,printed ,,by ,,william ,,clowes ,,and
 ,,sons1 ,,limited1 ,,stamford          
,,street ,,and ,,charing ,,cross4       
,plate #a4  ,illustration3              
,,reproduction ,,of ,,tones ,,in ,,the  
,,electro-,,galvanic ,,way4      ,,thos4
 ,,kell  ,,son4 ,,lith #dj1 ,,king ,st4 
,,covent ,,garden _/   ,,reproduction   
,,of ,,tones ,,in ,,the                 
,,electro-,,galvanic ,,way4             
,illustration      ,,thos4 ,,kell       
,,son4 ,,lith #dj1 ,,king ,st4 ,,covent 
,,garden _/     ,,books ,,relating  ,,to
  ,,applied ,,science  ,,published ,,by 
,e4  ,f4 ,n4 ,,spon1  ,,london3 #af1    
,,charing ,,cross4  ,,new ,,york3 #dd1  

,,murray ,,street4       ,a             
,pocket-,book for ,chemists1 ,chemical  
,manufacturers1     ,metallurgists1     
,dyers1 ,distillers1 ,brewers1 ,sugar   
,refiners1     ,photographers1          
,students1 etc41 etc4 ,by ,thomas       
,bayley1 ,assoc4     ,r4,c4 ,sc4        
,ireland1 ,analytical and ,consulting   
,chemist and     ,assayer4 ,second      
edition1 with additions1 #dcg pp41 royal
 #cbmo1     roan1 gilt edges1 #es4      
,,synopsis ,,of ,,contents3             
,atomic ,weights and ,factors--,useful  
,data--,chemical                        
,calculations--,rules for ,indirect     
,analysis--,weights       and           
,measures--,thermometers and            
,barometers--,chemical                  
,physics--,boiling ,points1             
etc4--,solubility of                    
,substances--,methods of ,obtaining     
,specific       ,gravity--,conversion of
 ,hydrometers--,strength of ,solutions  
by ,specific ,gravity--,analysis--,gas  
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,analysis--,qualitative ,analysis and   
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assaying--,alcohol--,beer--,sugar       
--,miscellaneous ,technological matter  
relating to ,potash1       ,soda1       
,sulphuric ,acid1 ,chlorine1 ,tar       
,products1 ,petroleum1       ,milk1     
,tallow1 ,photography1 ,prices1 ,wages1 
,appendix1 etc41       etc4      ,the   
,mechanician3 ,a ,treatise on the       
,construction and     ,manipulation of  
,tools1 for the use and instruction of  
,young     ,engineers and ,scientific   
,amateurs1 comprising the ,arts of      
,blacksmithing and ,forging2 the        
,construction and ,manufacture     of   
,hand ,tools1 and the various ,methods  
of ,using and ,grinding     them2 the   
,construction of ,machine ,tools1 and   
how to work     them2 ,machine ,fitting 
and ,erection2 description of ,hand and 
,machine ,processes2 ,turning and ,screw
 ,cutting2 principles of                
,constructing and details of ,making and

 ,erecting ,steam ,engines1     and the 
various details of setting out work1    
etc41 etc4 ,by     ,cameron ,knight1    
,engineer4 ,containing #aadg            
illustrations1     and #cig pages of    
letter-press4 ,third edition1 #dto1     
cloth1 #ahs4       ,on ,designing ,belt 
,gearing4 ,by ,e4 ,j4 ,cowling ,welch1  
,mem4 ,inst4     ,mech4 ,engineers1     
,author of #8,designing ,valve          
,gearing4' ,fcap4     #hvo1 sewed1 #f;d4
       ,a ,handbook of ,formul1 ,tables1
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,surveyors and others engaged in        
,building4 ,by ,j4     ,t4 ,hurst1      
,c4,e4 ,thirteenth edition1 royal #cbmo1
 roan1 #es4        8,it is no           
disparagement to the many excellent     
publications       we refer to1 to say  
that in our opinion this little         
pocket-book of ,hurst's is the very best
 of them all1       without any         
exception4 ,it would be useless to      
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contents1 for it appears to contain     

almost everything that anyone connected 
with building       could require1 and1 
best of all1 made up in a compact form  
for carrying in the pocket1 measuring   
only #e in4 by #c in41       and about  
in4 thick1 in a limp cover4 ,we         
congratulate       the author on the    
success of his laborious and practically
       compiled little book1 which has  
received unqualified and       deserved 
praise from every professional person to
 whom we       have shown it40--,the    
,dublin ,builder4       ,the ,cabinet   
,maker2 being a ,collection of the most 
approved     designs in the ,medival1   
,louis-,seize1 and ,old ,english styles1
     for the use of ,cabinet ,makers1   
,carvers1 c4 ,by ,r4 ,charles4 #if      
plates1 folio1 half-bound1 #ajs4 #f;d4  
,quantity ,surveying4 ,by ,j4 ,leaning4 
,with #db illustrations1     crown #hvo1
 cloth1 #is4                            
,contents3        ,a complete           
,explanation of the ,london ,practice4  
,general ,instructions4       ,order of 

,taking ,off4       ,modes of           
,measurement of the various ,trades4    
,use and ,waste4       ,ventilation and 
,warming4       ,credits1 with various  
,examples of ,treatment4                
,abbreviations4       ,squaring the     
,dimensions4       ,abstracting1 with   
,examples in illustration of each       
,trade4       ,billing4       ,examples 
of ,preambles to each ,trade4           
,form for a ,bill of ,quantities4       
,do4 ,bill of ,credits4       ,do4 ,bill
 for ,alternative ,estimate4            
,restorations and ,repairs1 and ,form of
 ,bill4       ,variations before        
,acceptance of ,tender4       ,errors in
 a ,builder's ,estimate4       ,schedule
 of ,prices4       ,form of ,schedule of
 ,prices4       ,analysis of ,schedule  
of ,prices4       ,adjustment of        
,accounts4       ,form of a ,bill of    
,variations4       ,remarks on          
,specifications4       ,prices and      
,valuation of ,work1 with ,examples and 
,remarks         upon each ,trade4      

,the ,law as it affects ,quantity       
,surveyors1 with ,law ,reports4         
,taking ,off after the ,old ,method4    
,northern ,practice4       ,the ,general
 ,statement of the ,methods recommended 
by the        ,manchester ,society of   
,architects for taking ,quantities4     
,examples of ,collections4              
,examples of 8,taking ,off0 in each     
,trade4       ,remarks on the ,past and 
,present ,methods of ,estimating4       
,a ,practical ,treatise on ,heat1 as    
applied to the ,useful ,arts2     for   
the ,use of ,engineers1 ,architects1 c4 
,by ,thomas ,box4 ,with     #ad plates4 
,third edition1 crown #hvo1 cloth1 #abs4
 #f;d4       ,a ,descriptive ,treatise  
on ,mathematical ,drawing ,instruments3 
their construction1 uses1 qualities1    
selection1 preservation1     and        
suggestions for improvements1 with hints
 upon ,drawing and     ,colouring4 ,by  
,w4 ,f4 ,stanley1 ,m4 ,r4 ,i4 ,fifth    
edition1 with     numerous              
illustrations1 crown #hvo1 cloth1 #es4  

,spons' ,architects' and ,builders'     
,pocket-,book of ,prices and            
,memoranda4 ,edited by ,w4 ,young1      
,architect4 ,royal #cbmo1 roan1     #ds4
 #f;d42 or cloth1 red edges1 #cs4 #f;d4 
,published     annually4 ,tenth edition4
 ,now ready4       ,long-,span ,railway 
,bridges1 comprising ,investigations of 
the     ,comparative ,theoretical and   
,practical ,advantages of the various   
adopted or proposed ,type ,systems of   
,construction1 with numerous     ,formul
 and ,tables giving the weight of ,iron 
or ,steel required     in ,bridges from 
#cjj feet to the limiting ,spans2 to    
which are     added similar             
,investigations and ,tables relating to 
,short-span     ,railway ,bridges4      
,second and revised edition4 ,by ,b4    
,baker1     ,assoc4 ,inst4 ,c4,e4       
,plates1 crown #hvo1 cloth1 #es4        
,elementary ,theory and ,calculation of 
,iron ,bridges and ,roofs4     ,by      
,august ,ritter1 ,ph4,d41 ,professor at 
the ,polytechnic ,school at             

,aix-la-,chapelle4 ,translated from the 
third ,german edition1 by     ,h4 ,r4   
,sankey1 ,capt4 ,r4,e4 ,with #ejj       
illustrations1 #hvo1 cloth1     #aes4   
,the ,builder's ,clerk3 a ,guide to the 
,management of a ,builder's             
,business4 ,by ,thomas ,bales4 ,fcap4   
#hvo1 cloth1 #as4 #f;d4       ,the      
,elementary ,principles of ,carpentry4  
,by ,thomas ,tredgold4     ,revised from
 the original edition1 and partly       
re-written1 by     ,john ,thomas ,hurst4
 ,contained in #eag pages of            
letter-press1 and     illustrated with  
#dh plates and #aej wood engravings4    
,third     edition1 crown #hvo1 cloth1  
#ahs4        ,section ,i4 ,on the       
,equality and ,distribution of          
,forces--,section ,,ii4 ,resistance of  
,timber--,section       ,,iii4          
,construction of ,floors--,section ,,iv4
 ,construction       of ,roofs--,section
 ,v4 ,construction of ,domes and        
,cupolas--,section ,,vi4 ,construction  
of ,partitions--,section       ,,vii4   

,scaffolds1 ,staging1 and               
,gantries--,section ,,viii4             
,construction of ,centres for           
,bridges--,section ,,ix4                
,coffer-dams1 ,shoring1 and             
,strutting--,section ,x4 ,wooden        
,bridges and ,viaducts--,section ,,xi4  
,joints1 ,straps1 and other             
,fastenings--,section ,,xii4 ,timber4   
,our ,factories1 ,workshops1 and        
,warehouses3 their ,sanitary and        
,fire-,resisting ,arrangements4 ,by ,b4 
,h4 ,thwaite1 ,assoc4 ,mem4     ,inst4  
,c4,e4 ,with #ahc wood engravings1 crown
 #hvo1 cloth1 #is4       ,gold3 ,its    
,occurrence and ,extraction1 embracing  
the     ,geographical and ,geological   
,distribution and the ,mineralogical    
,characters of ,gold-bearing rocks2 the 
peculiar features and     modes of      
working ,shallow ,placers1 ,rivers1 and 
,deep ,leads2     ,hydraulicing2 the    
,reduction and ,separation of           
,auriferous     ,quartz2 the treatment  
of complex ,auriferous ores containing  

other metals2 a ,bibliography of the    
subject and a ,glossary of              
,technical and ,foreign ,terms4 ,by     
,alfred ,g4 ,lock1 ,f4,r4,g4,s4 ,with   
numerous illustrations and maps1 #abej  
pp41 super-royal #hvo1     cloth1 #bl4  
#abs4 #f;d4       ,progressive ,lessons 
in ,applied ,science4 ,by ,edward ,sang1
     ,f4,r4,s4,e4 ,crown #hvo1 cloth1   
each ,part1 #cs4        ,part #a4       
,geometry on ,paper--,part #b4          
,solidity1 ,weight1 and                 
,pressure--,part #c4 ,trigonometry1     
,vision1 and ,surveying                 
,instruments4       ,a ,practical       
,treatise on ,coal ,mining4 ,by ,george 
,g4 ,andr1     ,f4,g4,s41 ,assoc4 ,inst4
 ,c4,e41 ,member of the ,society of     
,engineers4     ,with #hb lithographic  
plates4 #b vols41 royal #dto1 cloth1    
#cl4 #abs4       ,sugar ,growing and    
,refining3 a ,comprehensive ,treatise on
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,plants1 and the ,manufacture1          
,refining1 and ,analysis of ,cane1      

,beet1 ,maple1 ,milk1 ,palm1            
,sorghum1 and ,starch ,sugars1 with     
copious statistics of their             
production and commerce1 and a chapter  
on the distillation of     ,rum4 ,by    
,charles ,g4 ,warnford ,lock1 ,f4,l4,s41
 c41 and ,g4 ,w4 ,wigner     and ,r4 ,h4
 ,harland1 ,,ff4,c4,s41 ,,ff4,i4,c4     
,with #bje illustrations1     #hvo1     
cloth1 #cjs4       ,spons' ,information 
for ,colonial ,engineers4 ,edited by ,j4
 ,t4     ,hurst4 ,demy #hvo1 sewed4     
,no4 #a4 ,ceylon4 ,by ,abraham ,deane1  
,c4,e4 #bs4 #f;d4                       
,,contents3        ,introductory        
,remarks--,natural                      
,productions--,architecture       and   
,engineering--,topography1 ,trade1 and  
,natural       ,history--,principal     
,stations--,weights and ,measures1 etc41
       etc4        ,no4 #b4 ,southern   
,africa1 including the ,cape ,colony1   
,natal1 and       the ,dutch ,republics4
 ,by ,henry ,hall1 ,f4,r4,g4,s41        
,f4,r4,c4,i4 ,with       ,map4 #cs4     

#f;d4                                   
,,contents3        ,general ,description
 of ,south ,africa--,physical ,geography
       with reference to ,engineering   
,operations--,notes on ,labour       and
 ,material in ,cape ,colony--,geological
 ,notes on ,rock       ,formation in    
,south ,africa--,engineering            
,instruments for       ,use in ,south   
,africa--,principal ,public ,works in   
,cape       ,colony3 ,railways1         
,mountain ,roads and ,passes1 ,harbour  
,works1 ,bridges1 ,gas ,works1          
,irrigation and ,water ,supply1         
,lighthouses1 ,drainage and ,sanitary   
,engineering1 ,public       ,buildings1 
,mines--,table of ,woods in ,south      
,africa--,animals       used for        
,draught ,purposes--,statistical        
,notes--,table of                       
,distances--,rates of ,carriage1 etc4   
,no4 #c4 ,india4 ,by ,f4 ,c4 ,danvers1  
,assoc4 ,inst4 ,c4,e4 ,with ,map4       
#ds4 #f;d4                              
,,contents3        ,physical ,geography 

of ,india--,building                    
,materials--,roads--,railways--,bridges-
-,irrigation--,river                    
,works--,harbours--,lighthouse          
,buildings--,native       ,labour--,the 
,principal ,trees of                    
,india--,money--,weights and            
,measures--,glossary of ,indian ,terms1 
etc4       ,a ,practical ,treatise on   
,casting and ,founding1 including       
descriptions of the modern machinery    
employed in the art4 ,by ,n4     ,e4    
,spretson1 ,engineer4 ,third edition1   
with #hb plates drawn to     scale1 #dab
 pp41 demy #hvo1 cloth1 #ahs4      ,the 
,clerk of ,works3 a ,vade-,mecum for all
 engaged in the     ,superintendence of 
,building ,operations4 ,by ,g4 ,g4      
,,hoskins1     ,f4,r4,i4,b4,a4 ,third   
edition1 fcap4 #hvo1 cloth1 #as4 #f;d4  
,tropical ,agriculture2 or1 the         
,culture1 ,preparation1 ,commerce1      
and ,consumption of the ,principal      
,products of the ,vegetable             
,kingdom1 as furnishing ,food1          

,clothing1 ,medicine1 etc41 and     in  
their relation to the ,arts and         
,manufactures2 forming a     practical  
treatise and ,handbook of ,reference for
 the ,colonist1     ,manufacturer1      
,merchant1 and ,consumer1 on the        
,cultivation1     ,preparation for      
,shipment1 and ,commercial ,value1 etc41
 of the     various ,substances obtained
 from ,trees and ,plants entering into  
the ,husbandry of ,tropical and         
,sub-,tropical ,regions4 ,by ,p4 ,l4    
,,simmonds4 ,second edition1 revised and
 improved1 #eae pages1 #hvo1     cloth1 
#al4 #as4      ,steel3 its ,history1    
,manufacture1 and ,uses4 ,by ,j4 ,s4    
,,jeans1     ,secretary of the ,iron and
 ,steel ,institute4 #hfj pages and #bd  
plates1 #hvo1 cloth1 #cfs4              
,american ,foundry ,practice3 ,treating 
of ,loam1 ,dry ,sand1 and     ,green    
,sand ,moulding1 and containing a       
,practical ,treatise upon     the       
,management of ,cupolas1 and the        
,melting of ,iron4 ,by ,t4     ,d4      

,,west1 ,practical ,iron ,moulder and   
,foundry ,foreman4 ,second     edition1 
with numerous illustrations1 crown #hvo1
 cloth1     #ajs4 #f;d4      ,the       
,maintenance of ,macadamised ,roads4 ,by
 ,t4 ,,codrington1     ,m4,i4,c4,e1     
,f4,g4,s41 ,general ,superintendent of  
,county ,roads for     ,south ,wales4   
#hvo1 cloth1 #fs4      ,hydraulic ,steam
 and ,hand ,power ,lifting and ,pressing
     ,machinery4 ,by ,,frederick        
,,colyer1 ,m4 ,inst4 ,c4,e41 ,m4 ,inst4 
,m4,e4     ,with #gc plates1 #hvo1      
cloth1 #ahs4      ,pumps and ,pumping   
,machinery4 ,by ,f4 ,,colyer1           
,m4,i4,c4,e41 ,m4,i4,m4,e4     ,with #bc
 folding plates1 #hvo1 cloth1 #abs4     
#f;d4      ,tables of the ,principal    
,speeds occurring in ,mechanical        
,engineering1 expressed in metres in a  
second4 ,by ,p4 ,,keerayeff1     ,chief 
,mechanic of the ,obouchoff ,steel      
,works1 ,st4 ,petersburg2     translated
 by ,,sergius ,,kern1 ,m4,e4 ,fcap4     
#hvo1 sewed1 #f;d4      ,girder ,making 

and the ,practice of ,bridge ,building  
in ,wrought     ,iron1 illustrated by   
,examples of ,bridges1 ,piers1 and      
,girder     ,work1 etc41 constructed at 
the ,skerne ,iron ,works1 ,darlington1  
by ,,edward ,,hutchinson1 ,m4 ,inst4    
,m4,e4 ,with #ce plates1 demy #hvo1     
cloth1 #ajs4 #f;d4      ,spons'         
,dictionary of ,engineering1 ,civil1    
,mechanical1     ,military1 and ,naval2 
with technical terms in ,french1        
,german1     ,italian1 and ,spanish1    
#cajj pp41 and nearly #hjjj engravings1 
in super-royal #hvo1 in #h divisions1   
#el4 #hs4 ,complete     in #c vols41    
cloth1 #el4 #es4 ,bound in a superior   
manner1     half-morocco1 top edge gilt1
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,see page #ae4      ,a ,treatise on the 
,origin1 ,progress1 ,prevention1 and    
,cure of     ,dry ,rot in ,timber2 with 
,remarks on the ,means of ,preserving   
,wood from ,destruction by ,sea-,worms1 
,beetles1 ,ants1 etc4 ,by     ,,thomas  
,,allen ,,britton1 late ,surveyor to the

 ,metropolitan ,board     of ,works1    
etc41 etc4 ,with #aj plates1 crown #hvo1
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,tables4 ,by ,g4 ,l4 ,,molesworth1      
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#f;d4                                   
,,contents4        ,general--,linear    
,measures--,square                      
,measures--,cubic ,measures--,measures  
of                                      
,capacity--,weights--,combinations--,the
rmometers4      ,a ,handbook of         
,electrical ,testing4 ,by ,h4 ,r4       
,,kempe1 ,member of     the ,society of 
,telegraph ,engineers4 ,new edition1    
revised and     enlarged1 with #ha      
illustrations4 ,crown #hvo1 cloth1 #abs4
     #f;d4      ,electro-,telegraphy4   
,by ,,frederick ,s4 ,,beechey1          
,telegraph     ,engineer4 ,a ,book for  
,beginners4 ,illustrated4 ,fcap4 #hvo1  
sewed1 #f;d4      ,handrailing3 by the  
,square ,cut4 ,by ,,john ,,jones1       
,staircase     ,builder4 ,fourth        
edition1 with seven plates1 #hvo1 cloth1

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the ,square ,cut4 ,by ,,john ,,jones1   
,staircase     ,builder4 ,part ,second1 
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#f;d4      ,the ,gas ,consumer's ,handy 
,book4 ,by ,,william ,,richards1 ,c4,e4 
,illustrated4 #ahmo1 sewed1 #f;d4       
,steam ,pleating for ,buildings2 or1    
,hints to ,steam ,fitters1     being a  
description of ,steam ,heating          
,apparatus for ,warming and             
,ventilating ,private ,houses and large 
,buildings2 with ,remarks on     ,steam1
 ,water1 and ,air in their relation to  
,heating2 to which     are added        
miscellaneous ,tables4 ,by ,j4 ,w4      
,,baldwin1 ,steam ,heating              
,engineer4 ,with many illustrations4    
,second edition1 crown #hvo1     cloth1 
#ajs4 #f;d4      ,a ,pocket-,book of    
,useful ,formul and ,memoranda for      
,civil and     ,mechanical ,engineers4  
,by ,,guilford ,l4 ,,molesworth1 ,mem4  
,inst4     ,c4,e41 ,consulting ,engineer
 to the ,government of ,india for ,state

     ,railways4 ,with numerous          
illustrations1 #gdd pp4 ,twenty-first   
edition1 revised and enlarged1 #cbmo1   
roan1 #fs4                              
,,synopsis ,,of ,,contents3             
,surveying1 ,levelling1 etc4--,strength 
and ,weight of                          
,materials--,earthwork1 ,brickwork1     
,masonry1 ,arches1       etc4--,struts1 
,columns1 ,beams1 and                   
,trusses--,flooring1       ,roofing1 and
 ,roof ,trusses--,girders1 ,bridges1    
etc4--,railways       and               
,roads--,hydraulic ,formul--,canals1    
,sewers1 ,waterworks1                   
,docks--,irrigation and                 
,breakwaters--,gas1 ,ventilation1       
and ,warming--,heat1 ,light1 ,colour1   
and ,sound--,gravity3       ,centres1   
,forces1 and ,powers--,millwork1 ,teeth 
of       ,wheels1 ,shafting1            
etc4--,workshop ,recipes--,sundry       
,machinery--,animal ,power--,steam and  
the ,steam       ,engine--,water-power1 
,water-wheels1 ,turbines1 etc4--,wind   

and ,windmills--,steam ,navigation1     
,ship ,building1       ,tonnage1        
etc4--,gunnery1 ,projectiles1           
etc4--,weights1       ,measures1 and    
,money--,trigonometry1 ,conic ,sections1
 and                                    
,curves--,telegraphy--,mensuration--,tab
les of ,areas and       ,circumference1 
and ,arcs of ,circles--,logarithms1     
,square       and ,cube ,roots1         
,powers--,reciprocals1 etc4--,useful    
,numbers--,differential and ,integral   
,calculus--,algebraic                   
,signs--,telegraphic ,construction and  
,formul4      ,spons' ,tables and       
,memoranda for ,engineers2 selected and 
arranged by ,j4 ,t4 ,,hurst1 ,c4,e41    
,author of #8,architectural             
,surveyors' ,handbook1' #8,hurst's      
,tredgold's ,carpentry1#8 etc4          
,fifth edition1 #fdmo1 roan1 gilt edges1
 #as42 or in cloth case1     #as4 #f;d4 
,this work is printed in a pearl type1  
and is so small1       measuring only #b
 in4 by #a in4 by  in4 thick1 that it   

may       be easily carried in the      
waistcoat pocket4        8,it is        
certainly an extremely rare thing for a 
reviewer       to be called upon to     
notice a volume measuring but #b in4    
by #a in41 yet these dimensions         
faithfully represent the       size of  
the handy little book before us4 ,the   
volume--which       contains #aah       
printed pages1 besides a few blank pages
 for       memoranda--is1 in fact1 a    
true pocket-book1 adapted for           
being carried in the waistcoat pocket1  
and containing a       far greater      
amount and variety of information than  
most       people would imagine could be
 compressed into so small       a       
space4444 ,the little volume has been   
compiled with       considerable care   
and judgment1 and we can cordially      
recommend it to our readers as a useful 
little pocket                           
companion40--,engineering4              
,analysis1 ,technical ,valuation1       
,purification and ,use of ,coal         

,gas4 ,by the ,rev4 ,w4 ,r4 ,,bowditch1 
,m4,a4 ,with wood engravings1     #hvo1 
cloth1 #abs4 #f;d4        ,condensation 
of ,gas--,purification of               
,gas--,light--,measuring--,place of     
,testing ,gas--,test                    
,candles--,the ,standard for ,measuring 
,gas-light--,test                       
,burners--,testing ,gas for             
,sulphur--,testing ,gas for             
,ammonia--,condensation by              
,bromine--,gravimetric ,method       of 
taking ,specific ,gravity of            
,gas--,carburetting or                  
,naphthalizing                          
,gas--,acetylene--,explosions of        
,gas--,gnawing of       ,gaspipes by    
,rats--,pressure as related to ,public  
,lighting1       etc4      ,a ,practical
 ,treatise on ,natural and ,artificial  
,concrete1 its     ,varieties and       
,constructive ,adaptations4 ,by ,,henry 
,,reid1 ,author     of the #8,science   
and ,art of the ,manufacture of         
,portland ,cement4'     ,new ,edition1  

with #ei woodcuts and #e plates1 #hvo1  
cloth1 #aes4      ,hydrodynamics3       
,treatise relative to the ,testing of   
,water-,wheels and ,machinery1 with     
various other matters     pertaining to 
,hydrodynamics4 ,by ,,james ,,emerson4  
,with numerous     illustrations1 #cfj  
pp4 ,third edition1 crown #hvo1 cloth1  
#ds4     #f;d4      ,the ,gas ,analyst's
 ,manual4 ,by ,f4 ,w4 ,,hartley1 ,assoc4
 ,inst4     ,c4,e41 etc4 ,with numerous 
illustrations4 ,crown #hvo1 cloth1      
#fs4      ,gas ,measurement and ,gas    
,meter ,testing4 ,by ,f4 ,w4 ,,hartley4 
,fourth edition1 revised and extended4  
,illustrated1 crown #hvo1     cloth1    
#ds4      ,the ,french-,polishers       
,manual4 ,by a ,french-,polisher2       
containing     ,timber ,staining1       
,washing1 ,matching1 ,improving1        
,painting1     ,imitations1 ,directions 
for ,staining1 ,sizing1 ,embodying1     
,smoothing1 ,spirit ,varnishing1        
,french-,polishing1 ,directions for     
,repolishing4 ,third edition1 royal     

#cbmo1 sewed1 #f;d4      ,hops1 their   
,cultivation1 ,commerce1 and ,uses in   
various     ,countries4 ,by ,p4 ,l4     
,,simmonds1 ,crown #hvo1 cloth1 #ds4    
#f;d4      ,a ,practical ,treatise on   
the ,manufacture and ,distribution of   
,coal ,gas4 ,by ,,william ,,richards4   
,demy #dto1 with numerous wood          
engravings and #bi plates1 cloth1 #bhs4 
,,synopsis ,,of ,,contents3             
,introduction--,history of ,gas         
,lighting--,chemistry of ,gas           
,manufacture1 by ,lewis ,thompson1      
,esq41 ,m4,r4,c4,s4--,coal1       with  
,analyses1 by ,j4 ,paterson1 ,lewis     
,thompson1 and       ,g4 ,r4 ,hislop4   
,esqrs4--,retorts1 ,iron and            
,clay--,retort                          
,setting--,hydraulic                    
,main--,condensers--,exhausters--,washer
s       and                             
,scrubbers--,purifiers--,purification--,
history       of ,gas ,holder--,tanks1  
,brick and ,stone1       ,composite1    
,concrete1 ,cast-iron1 ,compound        

,annular                                
,wrought-iron--,specifications--,gas    
,holders--,station                      
,meter--,governor--,distribution--,mains
--,gas       ,mathematics1 or ,formul   
for the ,distribution of       ,gas1 by 
,lewis ,thompson1                       
,esq4--,services--,consumers'           
,meters--,regulators--,burners--,fitting
s--,photometer--,carburization       of 
,gas--,air ,gas and ,water              
,gas-,composition of ,coal ,gas1        
by ,lewis ,thompson1 ,esq4--,analyses of
 ,gas--,influence of       ,atmospheric 
,pressure and ,temperature on           
,gas--,residual                         
,products--,appendix--,description of   
,retort ,settings1       ,buildings1    
etc41 etc4      ,practical ,geometry and
 ,engineering ,drawing2 a ,course of    
,descriptive ,geometry adapted to the   
,requirements of the     ,engineering   
,draughtsman1 including the             
determination of cast     shadows and   
,isometric ,projection1 each chapter    

being followed     by numerous examples2
 to which are added rules for ,shading1 
,shade-lining1 etc41 together with      
practical instructions as     to the    
,lining1 ,colouring1 ,printing1 and     
general treatment of     ,engineering   
,drawings1 with a chapter on drawing    
,instruments4     ,by ,,george ,s4      
,,clarke1 ,lieut4 ,r4,e41 ,instructor in
 ,mechanical     ,drawing1 ,royal       
,indian ,engineering ,college4 #bj      
plates1 #dto1     cloth1 #aes4      ,the
 ,elements of ,graphic ,statics4 ,by    
,professor ,,karl ,,von ,,ott1          
translated from the ,german by ,g4 ,s4  
,,clarke1 ,lieut4 ,r4,e41               
,instructor in ,mechanical ,drawing1    
,royal ,indian ,engineering             
,college4 ,with #ic illustrations1 crown
 #hvo1 cloth1 #es4      ,the ,principles
 of ,graphic ,statics4 ,by ,,george     
,,sydenham ,,clarke1     ,lieut4 ,royal 
,engineers4 ,with #aab illustrations4   
#dto4 cloth1     #abs4 #f;d4      ,the  
,new ,formula for ,mean ,velocity of    

,discharge of ,rivers and     ,canals4  
,by ,w4 ,r4 ,,kutter4 ,translated from  
articles in the                         
#8,cultur-,ingenieur1' by ,,lowis ,d',a4
 ,,jackson1 ,assoc4 ,inst4 ,c4,e4       
#hvo1 cloth1 #abs4 #f;d4      ,practical
 ,hydraulics2 a ,series of ,rules and   
,tables for the     use of ,engineers1  
etc41 etc4 ,by ,,thomas ,,box4 ,fifth   
edition1     numerous plates1 post #hvo1
 cloth1 #es4      ,a ,practical         
,treatise on the ,construction of       
,horizontal     and ,vertical           
,waterwheels1 specially designed for the
 use     of operative mechanics4 ,by    
,,william ,,cullen1 ,millwright and     
,engineer4 ,with #aa plates4 ,second    
edition1 revised and     enlarged1 small
 #dto1 cloth1 #abs4 #f;d4      ,aid     
,book to ,engineering ,enterprise       
,abroad4 ,by ,,ewing     ,,matheson1 ,m4
 ,inst4 ,c4,e4 ,the book treats of      
,public ,works and     ,engineering     
,enterprises in their inception and     
preliminary     arrangement2 of the     

different modes in which money is       
provided for their accomplishment2 and  
of the economical     and technical     
considerations by which success or      
failure     is determined4 ,the         
information necessary to the designs of 
,engineers is classified1 as are also   
those particulars by which              
,contractors may estimate the cost of   
works1 and ,capitalists the             
probabilities of profit4 ,illustrated1  
#b vols41 #hvo1 #abs4     #f;d4 each4   
,the ,essential ,elements of ,practical 
,mechanics2 based on the     ,principle 
of ,work1 designed for ,engineering     
,students4 ,by     ,oliver ,byrne       
formerly ,professor of ,mathematics1    
,college for     ,civil ,engineers4     
,third edition1 with #adh wood          
engravings1     post #hvo1 cloth1 #gs4  
#f;d4                                   
,,contents3        ,chap4 ,i4 ,how ,work
 is ,measured by a ,unit1 both with and 
without reference to a ,unit of         
,time--,chap4 #b4 ,the ,work of         

,living ,agents1 the ,influence of      
,friction1 and introduces       one of  
the most beautiful ,laws of             
,motion--,chap4 #c4 ,the                
principles expounded in the first and   
second chapters are       applied to the
 ,motion of ,bodies--,chap4 #d4 ,the    
,transmission       of ,work by simple  
,machines--,chap4 #e4 ,useful           
,propositions       and ,rules4         
,the ,practical ,millwright's and       
,engineer's ,ready ,reckoner2     or    
,tables for finding the diameter and    
power of cog-wheels1     diameter1      
weight1 and power of shafts1 diameter   
and strength of     bolts1 etc4 ,by     
,thomas ,dixon4 ,fourth edition1 #abmo1 
cloth1 #cs4      ,breweries and         
,maltings3 their ,arrangement1          
,construction1     ,machinery1 and      
,plant4 ,by ,g4 ,scamell1               
,f4,r4,i4,b4,a4 ,second edition1        
revised1 enlarged1 and partly rewritten 
,by ,f4 ,colyer1 ,m4,i4,c4,e41          
,m4,i4,m4,e4 ,with #bj plates1 #hvo1    

cloth1 #ahs4      ,a ,practical         
,treatise on the ,manufacture of        
,starch1 ,glucose1     ,starch-,sugar1  
and ,dextrine1 based #jaa the ,german of
 ,l4 ,von     ,wagner1 ,professor in the
 ,royal ,technical ,school1 ,buda       
,pesth1     and other authorities4 ,by  
,julius ,frankel2 edited by ,robert     
,hutter1 proprietor of the ,philadelphia
 ,starch ,works4 ,with #eh              
illustrations1 #cdd pp41 #hvo1 cloth1   
#ahs4      ,a ,practical ,treatise on   
,mill-gearing1 ,wheels1 ,shafts1        
,riggers1     etc42 for the use of      
,engineers4 ,by ,thomas ,box4 ,third    
edition1     with #aa plates4 ,crown    
#hvo1 cloth1 #gs4 #f;d4      ,mining    
,machinery3 a ,descriptive ,treatise on 
the ,machinery1     ,tools1 and other   
,appliances used in ,mining4 ,by ,g4 ,g4
 ,andr1     ,f4,g4,s41 ,assoc4 ,inst4   
,c4,e41 ,mem4 of the ,society of        
,engineers4     ,royal #dto1 uniform    
with the ,author's ,treatise on ,coal   
,mining1     containing #ahb plates1    

accurately drawn to scale1 with         
descriptive text1 in #b vols41 cloth1   
#cl4 #abs4  ,,contents3      ,machinery 
for ,prospecting1 ,excavating1 ,hauling1
 and                                    
,hoisting--,ventilation--,pumping--,trea
tment of ,mineral ,products1            
including ,gold and ,silver1 ,copper1   
,tin1 and ,lead1 ,iron1 ,coal1          
,sulphur1 ,china ,clay1 ,brick ,earth1  
etc4      ,tables for ,setting out      
,curves for ,railways1 ,canals1 ,roads1 
etc41 varying from a radius of five     
chains to three miles4     ,by ,a4      
,kennedy and ,r4 ,w4 ,hackwood4         
,illustrated1 #cbmo1 cloth1     #bs4    
#f;d4      ,the ,science and ,art of the
 ,manufacture of ,portland ,cement1     
with observations on some of its        
constructive applications4     ,with #ff
 illustrations4 ,by ,henry ,reid1       
,c4,e41 ,author of #8,a     ,practical  
,treatise on ,concrete1' etc41 etc4     
#hvo1 cloth1 #ahs4      ,the            
,draughtsman's ,handbook of ,plan and   

,map ,drawing2 including                
instructions for the preparation of     
,engineering1 ,architectural1     and   
,mechanical ,drawings4 ,with numerous   
illustrations in the     text1 and #cc  
plates 7#ae printed in colours74 ,by ,g4
 ,g4 ,andr1     ,f4,g4,s41 ,assoc4      
,inst4 ,c4,e4 #dto1 cloth1 #is4         
,,contents3        ,the ,drawing ,office
 and its ,furnishings--,geometrical     
,problems--,lines1 ,dots1 and their     
,combinations--,colours1       ,shading1
 ,lettering1 ,bordering1 and ,north     
,points--,scales--,plotting--,civil     
,engineers' and ,surveyors'             
,plans--,map ,drawing--,mechanical and  
,architectural       ,drawing--,copying 
and ,reducing ,trigonometrical ,formul1 
etc41 etc4      ,the ,boiler-maker's and
 ,iron ,ship-builder's ,companion1      
comprising a series of original and     
carefully calculated     tables1 of the 
utmost utility to persons interested in 
the iron     trades4 ,by ,james ,foden1 
author of #8,mechanical ,tables1' etc4  

,second edition revised1 with           
illustrations1 crown #hvo1 cloth1       
#es4      ,rock ,blasting3 a ,practical 
,treatise on the means employed in      
,blasting ,rocks for ,industrial        
,purposes4 ,by ,g4 ,g4 ,andr1 ,f4,g4,s41
     ,assoc4 ,inst4 ,c4,e4 ,with #ef    
illustrations and #ab plates1 #hvo1     
cloth1 #ajs4 #f;d4      ,surcharged and 
different ,forms of ,retaining ,walls4  
,by ,j4 ,s4     ,tate4 ,illustrated1    
#hvo1 sewed1 #bs4      ,a ,treatise on  
,ropemaking as practised in public and  
private     ,rope-yards1 with a         
,description of the ,manufacture1       
,rules1     ,tables of ,weights1 etc41  
adapted to the ,trade1 ,shipping1       
,mining1 ,railways1 ,builders1 etc4 ,by 
,r4 ,chapman1 formerly     foreman to   
,messrs4 ,huddart and ,co41 ,limehouse1 
and late ,master     ,ropemaker to      
,h4,m4 ,dockyard1 ,deptford4 ,second    
edition1 #abmo1     cloth1 #cs4         
,laxton's ,builders' and ,contractors'  
,tables2 for the use of     ,engineers1 

,architects1 ,surveyors1 ,builders1     
,land ,agents1 and     others4          
,bricklayer1 containing #bb tables1 with
 nearly #cj1jjj     calculations4 #dto1 
cloth1 #es4      ,laxton's ,builders'   
and ,contractors' ,tables4 ,excavator1  
,earth1     ,land1 ,water1 and ,gas1    
containing #ec tables1 with nearly      
#bd1jjj     calculations4 #dto1 cloth1  
#es4      ,sanitary ,engineering3 a     
,guide to the ,construction of ,works   
of ,sewerage and ,house ,drainage1 with 
,tables for facilitating     the        
calculations of the ,engineer4 ,by      
,baldwin ,latham1 ,c4,e41 ,m4     ,inst4
 ,c4,e41 ,f4,g4,s41 ,f4,m4,s41          
,past-,president of the ,society of     
,engineers4 ,second edition1 with       
numerous plates and woodcuts1     #hvo1 
cloth1 #al4 #ajs4      ,screw ,cutting  
,tables for ,engineers and ,machinists1 
giving the     values of the different  
trains of ,wheels required to produce   
,screws of any pitch1 calculated by     
,lord ,lindsay1 ,m4,p41 ,f4,r4,s41      

,f4,r4,a4,s41 etc4 ,royal #hvo1 cloth1  
oblong1 #bs4      ,screw ,cutting       
,tables1 for the use of ,mechanical     
,engineers1     showing the proper      
arrangement of ,wheels for cutting the  
,threads of ,screws of any required     
pitch1 with a ,table for     making the 
,universal ,gas-pipe ,threads and ,taps4
 ,by ,w4 ,a4     ,martin1 ,engineer4    
,second edition1 royal #hvo1 oblong1    
cloth1     #as41 or sewed1 #f;d4      ,a
 ,treatise on a ,practical ,method of   
,designing ,slide-,valve     ,gears by  
,simple ,geometrical ,construction1     
based upon the     principles enunciated
 in ,euclid's ,elements1 and comprising 
the various forms of ,plain             
,slide-,valve and ,expansion ,gearing2  
together with ,stephenson's1 ,gooch's1  
and ,allan's ,link-,motions1     as     
applied either to reversing or to       
variable expansion     combinations4 ,by
 ,edward ,j4 ,cowling ,welch1 ,memb4    
,inst4     ,mechanical ,engineers4      
,crown #hvo1 cloth1 #fs4      ,cleaning 

and ,scouring3 a ,manual for ,dyers1    
,laundresses1 and     for ,domestic     
,use4 ,by ,s4 ,christopher4 #ahmo1      
sewed1 #f;d4      ,a ,handbook of ,house
 ,sanitation2 for the use of all persons
     seeking a ,healthy ,home4 ,a       
reprint of those portions of ,mr4       
,bailey-,denton's ,lectures on ,sanitary
 ,engineering1 given     before the     
,school of ,military ,engineering1 which
 related     to the 8,dwelling10        
enlarged and revised by his ,son1 ,e4   
,f4     ,bailey-,denton1 ,c4,e41 ,b4,a4 
,with #adj illustrations1 #hvo1 cloth1  
#hs4 #f;d4      ,treatise on            
,valve-,gears1 with special             
consideration of the     ,link-,motions 
of ,locomotive ,engines4 ,by ,dr4       
,gustav ,zeuner4 ,third     edition1    
revised and enlarged1 translated from   
the ,german1     with the special       
permission of the author1 by ,moritz    
,mller4     ,plates1 #hvo1 cloth1 #abs4 
#f;d4      ,a ,pocket-,book for ,boiler 
,makers and ,steam ,users1 comprising   

a variety of useful information for     
,employer and ,workman1     ,government 
,inspectors1 ,board of ,trade           
,surveyors1 ,engineers in     charge of 
,works and ,slips1 ,foremen of          
,manufactories1 and the     general     
,steam-using ,public4 ,by ,maurice ,john
 ,sexton4 ,second     edition1 royal    
#cbmo1 roan1 gilt edges1 #es4      ,the 
,strains upon ,bridge ,girders and ,roof
 ,trusses1 including     the ,warren1   
,lattice1 ,trellis1 ,bowstring1 and     
other ,forms of     ,girders1 the       
,curved ,roof1 and ,simple and ,compound
 ,trusses4 ,by     ,thos4 ,cargill1     
,c4,e4,b4,a4,t41 ,c4,d41 ,assoc4 ,inst4 
,c4,e41 ,member of     the ,society of  
,engineers4 ,with #fd illustrations1    
drawn and     worked out to scale1 #hvo1
 cloth1 #abs41 #f;d4      ,a ,practical 
,treatise on the ,steam ,engine1        
containing ,plans     and ,arrangements 
of ,details for ,fixed ,steam ,engines1 
with     ,essays on the ,principles     
involved in ,design and ,construction4  

,by ,arthur ,rigg1 ,engineer1 ,member of
 the ,society of ,engineers     and of  
the ,royal ,institution of ,great       
,britain4 ,demy #dto1     copiously     
illustrated with woodcuts and #if       
plates1 in one     ,volume1 half-bound  
morocco1 #bl4 #bs42 or cheaper edition1 
cloth1 #bes4        ,this work is not1  
in any sense1 an elementary treatise1 or
       history of the steam engine1 but 
is intended to describe       examples  
of ,fixed ,steam ,engines without       
entering into the       wide domain of  
locomotive or marine practice4 ,to this 
end       illustrations will be given of
 the most recent arrangements       of  
,horizontal1 ,vertical1 ,beam1 ,pumping1
 ,winding1 ,portable1                   
,semi-portable1 ,corliss1 ,allen1       
,compound1 and other similar            
,engines1 by the most eminent ,firms in 
,great ,britain and       ,america4 ,the
 laws relating to the action and        
precautions       to be observed in the 
construction of the various details1    

such as ,cylinders1 ,pistons1           
,piston-rods1 ,connecting-rods1         
,cross-heads1 ,motion-blocks1           
,eccentrics1 ,simple1 ,expansion1       
,balanced1 and ,equilibrium             
,slide-valves1 and ,valve-gearing       
will be minutely dealt with4 ,in this   
connection will be       found articles 
upon the ,velocity of ,reciprocating    
,parts and       the ,mode of ,applying 
the ,indicator1 ,heat and ,expansion of 
,steam ,governors1 and the like4 ,it is 
the writer's desire       to draw       
illustrations from every possible       
source1 and give       only those rules 
that present practice deems correct4    
,barlow's ,tables of ,squares1 ,cubes1  
,square ,roots1 ,cube ,roots1           
,reciprocals of all ,integer ,numbers up
 to #aj1jjj4 ,post #hvo1     cloth1 #fs4
      ,camus 7,m47 ,treatise on the     
,teeth of ,wheels1 demonstrating     the
 best forms which can be given to them  
for the purposes of     ,machinery1 such
 as ,mill-work and ,clock-work1 and the 

art of     finding their numbers4       
,translated from the ,french1 with      
details     of the present practice of  
,millwrights1 ,engine ,makers1 and      
other ,machinists1 by ,isaac ,hawkins4  
,third edition1 with #ah     plates1    
#hvo1 cloth1 #es4       ,a ,practical   
,treatise on the ,science of ,land and  
,engineering     ,surveying1 ,levelling1
 ,estimating ,quantities1 etc41 with a  
general description of the several      
,instruments required for               
,surveying1 ,levelling1 ,plotting1 etc4 
,by ,h4 ,s4 ,merrett4 ,third            
edition1 #da plates with illustrations  
and tables1 royal #hvo1     cloth1 #abs4
 #f;d4                                  
,,principal ,,contents3        ,part #a4
 ,introduction and the ,principles of   
,geometry4       ,part #b4 ,land        
,surveying2 comprising ,general         
,observations--,the ,chain--,offsets    
,surveying by the       ,chain          
only--,surveying ,hilly ,ground--,to    
,survey an       ,estate or ,parish by  

the ,chain only--,surveying with        
the ,theodolite--,mining and ,town      
,surveying--,railroad                   
,surveying--,mapping--,division and     
,laying out of                          
,land--,observations on                 
,enclosures--,plane ,trigonometry4      
,part #c4 ,levelling--,simple and       
,compound ,levelling--,the       ,level 
,book--,parliamentary ,plan and         
,section--,levelling       with a       
,theodolite--,gradients--,wooden        
,curves--,to ,lay       out a ,railway  
,curve--,setting out ,widths4 ,part #d4 
,calculating ,quantities generally for  
,estimates--,cuttings       and         
,embankments--,tunnels--,brickwork--,iro
nwork--,timber       ,measuring4 ,part  
#e4 ,description and ,use of            
,instruments in ,surveying and          
,plotting--,the       ,improved ,dumpy  
,level--,troughton's ,level--,the       
,prismatic ,compass--,proportional      
,compass--,box                          
,sextant--,vernier--,pantagraph--,merret

t's ,improved       ,quadrant--,improved
 ,computation ,scale--,the ,diagonal    
,scale--,straight ,edge and ,sector4    
,part #f4 ,logarithms       of          
,numbers--,logarithmic ,sines and       
,co-,sines1 ,tangents       and         
,co-,tangents--,natural ,sines and      
,co-,sines--,tables       for           
,earthwork1 for ,setting out ,curves1   
and for various       ,calculations1    
etc41 etc41 etc4      ,saws3 the        
,history1 ,development1 ,action1        
,classification1 and     ,comparison of 
,saws of all kinds4 ,by ,robert         
,grimshaw4 ,with #bbj     illustrations1
 #dto1 cloth1 #abs4 #f;d4      ,a       
,supplement to the above2 containing    
additional practical     matter1 more   
especially relating to the forms of ,saw
 ,teeth for     special material and    
conditions1 and to the behaviour of     
,saws     under particular conditions4  
,with #abj illustrations1 cloth1        
#is4      ,a ,guide for the ,electric   
,testing of ,telegraph ,cables4     ,by 

,capt4 ,v4 ,hoskir1 ,royal ,danish      
,engineers4 ,with     illustrations1    
second edition1 crown #hvo1 cloth1 #ds4 
#f;d4      ,laying and ,repairing       
,electric ,telegraph ,cables4 ,by ,capt4
 ,v4     ,hoskir1 ,royal ,danish        
,engineers4 ,crown #hvo1 cloth1 #cs4    
#f;d4      ,a ,pocket-,book of          
,practical ,rules for the ,proportions  
of ,modern     ,engines and ,boilers for
 ,land and ,marine purposes4 ,by ,n4 ,p4
     ,burgh4 ,seventh edition1 royal    
#cbmo1 roan1 #ds4 #f;d4      ,table of  
,logarithms of the ,natural ,numbers1   
from #a to     #ajh1jjj4 ,by ,charles   
,babbage1 ,esq41 ,m4,a4 ,stereotyped    
edition1     royal #hvo1 cloth1 #gs4    
#f;d4        ,to ensure the correctness 
of these ,tables of ,logarithms1        
they were compared with ,callett's1     
,vega's1 ,hutton's1       ,briggs'1     
,gardiner's1 and ,taylor's ,tables of   
,logarithms1       and carefully read by
 nine different readers2 and further1   
to remove any possibility of an error   

remaining1 the       stereotyped sheets 
were hung up in the ,hall at ,cambridge 
,university1 and a reward offered to    
anyone who could find       an          
inaccuracy4 ,so correct are these       
,tables1 that since       their first   
issue in #ahbg no error has been        
discovered4      ,the ,steam ,engine    
considered as a ,heat ,engine3 a        
,treatise     on the ,theory of the     
,steam ,engine1 illustrated by          
,diagrams1     ,tables1 and ,examples   
from ,practice4 ,by ,jas4 ,h4           
,cotterill1 ,m4,a41     ,f4,r4,s41      
,professor of ,applied ,mechanics in the
 ,royal ,naval     ,college4 #hvo1      
cloth1 #abs4 #f;d4      ,the ,practice  
of ,hand ,turning in ,wood1 ,ivory1     
,shell1 etc41     with ,instructions for
 ,turning such ,work in ,metal as maybe 
required in the ,practice of ,turning in
 ,wood1 ,ivory1 etc42 also     an       
,appendix on ,ornamental ,turning4 7,a  
book for beginners47 ,by     ,francis   
,campin4 ,second edition1 with wood     

engravings1 crown     #hvo1 cloth1 #fs4 
,,contents3        ,on ,lathes--,turning
 ,tools--,turning                       
,wood--,drilling--,screw                
,cutting--,miscellaneous ,apparatus and 
,processes--,turning       ,particular  
,forms--,staining--,polishing--,spinning
       ,metals--,materials--,ornamental 
,turning1 etc4      ,health and ,comfort
 in ,house ,building1 or ,ventilation   
with ,warm     ,air by ,self-,acting    
,suction ,power1 with ,review of the    
mode     of ,calculating the ,draught in
 ,hot-,air ,flues1 and with some        
actual ,experiments4 ,by ,j4 ,drysdale1 
,m4,d41 and ,j4 ,w4 ,hayward1     ,m4,d4
 ,second edition1 with ,supplement1 with
 plates1 demy #hvo1     cloth1 #gs4     
#f;d4      ,treatise on ,watchwork1     
,past and ,present4 ,by the ,rev4 ,h4   
,l4     ,nelthropp1 ,m4,a41 ,f4,s4,a4   
,with #cb illustrations1 crown #hvo1    
cloth1 #fs4 #f;d4                       
,,contents3        ,definitions of      
,words and ,terms used in               

,watchwork--,tools--,time--,historical  
,summary--,on       ,calculations of the
 ,numbers for ,wheels and ,pinions2     
their ,proportional ,sizes1 ,trains1    
etc4--,of ,dial ,wheels1       or       
,motion ,work--,length of ,time of      
,going without ,winding       up--,the  
,verge--,the ,horizontal--,the          
,duplex--,the ,lever--,the              
,chronometer--,repeating                
,watches--,keyless ,watches--,the       
,pendulum1 or ,spiral                   
,spring--,compensation--,jewelling      
of ,pivot                               
,holes--,clerkenwell--,fallacies of the 
,trade--,incapacity of ,workmen--,how to
 ,choose and ,use a       ,watch1 etc4  
,spons' ,engineers' and ,contractors    
,illustrated ,book of ,prices     of    
,machines1 ,tools1 ,ironwork1 and       
,contractors' ,material2 and            
,engineers' ,directory4 ,third edition1 
#dto1 cloth1 #fs4      ,algebra         
,self-,taught4 ,by ,w4 ,p4 ,higgs1      
,m4,a41 ,d4,sc41 ,,ll4,d41     ,assoc4  

,inst4 ,c4,e41 ,author of #8,a ,handbook
 of the ,differential     ,calculus1'   
etc4 ,second edition1 crown #hvo1 cloth1
 #bs4 #f;d4                             
,,contents3        ,symbols and the     
,signs of ,operation--,the ,equation    
and the ,unknown ,quantity--,positive   
and ,negative                           
,quantities--,multiplication--,involutio
n--,exponents--,negative                
,exponents--,roots1 and the ,use of     
,exponents as                           
,logarithms--,logarithms--,tables of    
,logarithms and       ,proportionate    
,parts--,transformation of ,system of   
,logarithms--,common ,uses of ,common   
,logarithms--,compound                  
,multiplication and the ,binomial       
,theorem--,division1       ,fractions1  
and ,ratio--,continued ,proportion--,the
 ,series and       the ,summation of the
 ,series--,limit of ,series--,square and
       ,cube ,roots--,equations--,list  
of ,formul1 etc4                        
,,just ,,published4       ,in           

super-royal #hvo1 #aafh pp41 with #bdjj 
illustrations1 in #c      ,divisions1   
cloth1 price #acs4 #f;d4 each2 or #a    
vol41 cloth1                   #bl42 or 
half-morocco1 #bl4 #hs4                 
,a ,,supplement                         
,,to                     ,,spons'       
,,dictionary ,,of ,,engineering1        
,civil1 ,mechanical1 ,military and      
,naval4               ,edited by        
,,ernest ,,spon1 ,memb4 ,soc4           
,engineers4  ,the success which has     
attended the publication of #8,,spons'  
,,dictionary ,,of ,,engineering' has    
encouraged the ,publishers to use every 
effort tending to keep the work up to   
the standard of existing professional   
knowledge4 ,as the ,book has now been   
some years before the public without    
addition or revision1 there are many    
subjects of importance which1 of        
necessity1 are either not included in   
its pages1 or have been treated somewhat
 less fully than their present          
importance demands4 ,with the object1   

therefore1 of remedying these omissions1
 this ,supplement is now being issued4  
,each subject in it is treated in a     
thoroughly comprehensive way2 but1 of   
course1 without repeating the           
information already included in the body
 of the work4  ,the new matter comprises
 articles upon    ,abacus1 ,counters1   
,speed ,indicators1 and ,slide ,rule4   
,agricultural ,implements and           
,machinery4   ,air ,compressors4        
,animal ,charcoal ,machinery4           
,antimony4   ,axles and ,axle-boxes4    
,barn ,machinery4   ,belts and ,belting4
   ,blasting4   ,boilers4   ,brakes4    
,brick ,machinery4   ,bridges4   ,cages 
for ,mines4   ,calculus1 ,differential  
and ,integral4   ,canals4   ,carpentry4 
,cast ,iron4   ,cement1 ,concrete1      
,limes1 and ,mortar4   ,chimney ,shafts4
   ,coal ,cleansing and ,washing4       
,coal ,mining4   ,coal ,cutting         
,machines4   ,coke ,ovens4   ,copper4   
,docks4   ,drainage4   ,dredging        
,machinery4   ,dynamo-,electric and     

,magneto-,electric ,machines4           
,dynamometers4   ,electrical            
,engineering1 ,telegraphy1 ,electric    
,lighting and its     practical details1
 ,telephones4   ,engines1 ,varieties of4
   ,explosives4   ,fans4   ,founding1   
,moulding and the practical work of the 
,foundry4   ,gas1 ,manufacture of4      
,hammers1 ,steam and other ,power4      
,heat4   ,horse ,power4   ,hydraulics4  
,hydro-geology4   ,indicators4   ,iron4 
,lifts1 ,hoists1 and ,elevators4        
,lighthouses1 ,buoys1 and ,beacons4     
,machine ,tools4   ,materials of        
,construction4   ,meters4   ,ores1      
,machinery and ,processes employed to   
,dress4   ,piers4   ,pile ,driving4     
,pneumatic ,transmission4   ,pumps4     
,pyrometers4   ,road ,locomotives4      
,rock ,drills4   ,rolling ,stock4       
,sanitary ,engineering4   ,shafting4    
,steel4   ,steam ,navvy4   ,stone       
,machinery4   ,tramways4   ,well        
,sinking4                               
,,now ,,complete4        ,with nearly   

#aejj illustrations1 in super-royal     
#hvo1 in #e     ,divisions1 cloth4      
,divisions #a to #d1 #acs4 #f;d4 each2  
,division              #e1 #ags4 #f;d42 
or #b vols41 cloth1 #c #ajs4            
,,spons' ,,encyclop,,dia                
,,of ,,the          ,,industrial ,,arts1
 ,,manufactures1 ,,and ,,commercial     
,,products4                   ,edited by
 ,c4 ,g4 ,,warnford ,,lock1 ,f4,l4,s4   
,among the more important of the        
subjects treated of1 are the            
following3--    ,acids1 #bjg pp4 #bbj   
figs4   ,alcohol1 #bc pp4 #af figs4     
,alcoholic ,liquors1 #ac pp4            
,alkalies1 #hi pp4 #gh figs4   ,alloys4 
,alum4   ,asphalt4   ,assaying4         
,beverages1 #hi pp4 #bi figs4   ,blacks4
   ,bleaching ,powder1 #ae pp4          
,bleaching1 #ea pp4 #dh figs4           
,candles1 #ah pp4 #i figs4   ,carbon    
,bisulphide4   ,celluloid1 #i pp4       
,cements4   ,clay4   ,coal-tar          
,products1 #dd pp4 #ad figs4   ,cocoa1  
#h pp4   ,coffee1 #cb pp4 #ac figs4     

,cork1 #h pp4 #ag figs4   ,cotton       
,manufactures1 #fb pp4 #eg figs4        
,drugs1 #ch pp4   ,dyeing and ,calico   
,printing1 #bh pp4 #i figs4             
,dyestuffs1 #af pp4                     
,electro-,metallurgy1 #ac pp4           
,explosives1 #bb pp4 #cc figs4          
,feathers4   ,fibrous ,substances1 #ib  
pp4 #gi figs4   ,floor-cloth1 #af pp4   
#ba figs4   ,food ,preservation1 #h pp4 
,fruit1 #h pp4   ,fur1 #e pp4   ,gas1   
,coal1 #h pp4   ,gems4   ,glass1 #de pp4
 #gg figs4   ,graphite1 #g pp4   ,hair1 
#g pp4   ,hair ,manufactures4   ,hats1  
#bf pp4 #bf figs4   ,honey4   ,hops4    
,horn4   ,ice1 #aj pp4 #ad figs4        
,indiarubber ,manufactures1 #bc pp4 #ag 
figs4   ,ink1 #ag pp4   ,ivory4   ,jute 
,manufactures1 #aa pp4 #aa figs4        
,knitted ,fabrics--,hosiery1 #ae pp4 #ac
 figs4   ,lace1 #ac pp4 #i figs4        
,leather1 #bh pp4 #ca figs4   ,linen    
,manufactures1 #af pp4 #f figs4         
,manures1 #ba pp4 #cj figs4   ,matches1 
#ag pp4 #ch figs4   ,mordants1 #ac pp4  

,narcotics1 #dg pp4   ,nuts1 #aj pp4    
,oils and ,fatty ,substances1 #abe pp4  
,paint4   ,paper1 #bf pp4 #bc figs4     
,paraffin1 #h pp4 #f figs4   ,pearl and 
,coral1 #h pp4   ,perfumes1 #aj pp4     
,photography1 #ac pp4 #bj figs4         
,pigments1 #i pp4 #f figs4   ,pottery1  
#df pp4 #eg figs4   ,printing and       
,engraving1 #bj pp4 #h figs4   ,rags4   
,resinous and ,gummy ,substances1 #ge   
pp4 #af figs4   ,rope1 #af pp4 #ag figs4
   ,salt1 #ca pp4 #bc figs4   ,silk1 #h 
pp4   ,silk ,manufactures1 #i pp4 #aa   
figs4   ,skins1 #e pp4   ,small ,wares1 
#d pp4   ,soap and ,glycerine1 #ci pp4  
#de figs4   ,spices1 #af pp4   ,sponge1 
#e pp4   ,starch1 #i pp4 #aj figs4      
,sugar1 #aee pp4 #acd figs4   ,sulphur4 
,tannin1 #ah pp4   ,tea1 #ab pp4        
,timber1 #ac pp4   ,varnish1 #ae pp4    
,vinegar1 #e pp4   ,wax1 #e pp4   ,wool1
 #b pp4   ,woollen ,manufactures1 #es   
pp4 #ci figs4   ,london3 ,e4  ,f4 ,n4   
,,spon1 #af1 ,charing ,cross4  ,new     
,york3 #dd1 ,murray ,street4