,a ,project for ,flying4    ,in ,earnest
 at ,last6    #ahga    ,price1          
,,twenty-,,five ,,cents4          ,a    
,project for ,flying4      ,in ,earnest 
,at ,last4        ,the following        
appeared in one of our public journals  
of the date  indicated    ,to the       
,editor of the ,tribune4    ,,sir3--,you
 rightly appreciate the interest with   
which the popular  mind regards all     
efforts in the direction of navigating  
the air4    ,one man of my acquaintance 
was deeply interested to know the       
results of the ,california ,experiment1 
because he alone1 as he believed1  had  
questioned ,nature and learned from her 
the great secret of aerial  navigation4 
,to-day's ,tribune brings us the full   
account of the machine1 its  performance
 and modus operandi2 and without the    
authority of my  friend1 ,i can         
pronounce at once that the thing is     
simply ridiculous4 ,it is  the same old 
useless effort1 with the same impossible
 agents4 ,but to-day1  within twenty    

miles of ,trinity steeple1 lives the man
 who can give to  the world the secret  
of navigating the air1 in calm or in    
storm1 with  the wind or against it2    
skimming the earth1 or in the highest   
currents1  just as he wills1 with all   
the ease1 and all the swiftness1 and all
 the  exactitude of a bird4    ,my      
friend is only waiting for an           
opportunity to perfect his plan1 when   
he will make it known4    ,yours truly1 
,w4,h4,k4    ,new ,york2 ,june #adth1   
#ahfi4    ,two years have passed and no 
progress has been made in aerial        
navigation4    ,the ,california         
,experiment failed4 ,the great ,airship 
,,city ,,of ,,new  ,,york1 had          
previously escaped the same fate1 only  
because more prudent  than her successor
 she declined a trial4 ,the promising   
and ambitious  enterprise of ,mr4       
,henson has hardly been spoken of for a 
quarter of a  century4 ,and             
notwithstanding the fact that the number
 of ascensions in  balloons in the      

,united ,states and ,europe must be     
counted by thousands1  and although the 
exigencies of recent wars have made them
 useful1 yet  it must be confessed that 
the art of navigating the air remains in
  much the same state in which the      
brothers ,montgolfiers left it at the   
close of the last century4    ,the      
reason for this want of progress in the 
art referred to1 is not to  be sought in
 any want of interest in the subject1 or
 of enthusiasm in  prosecuting          
experiments4 ,certainly not for want of 
interest in the  subject because to fly1
 has been the great desideratum of  the 
race since ,adam4 ,and we find in the   
literature of every age  suggestions for
 means of achieving flight through the  
air1 in  imitation of birds2 or for the 
construction of ingenious machines for  
aerial navigation4 ,and if history and  
traditions are to be credited1  it would
 be equally an error to suppose that our
 age alone had  attempted to put theory 
into practice in reference to navigating

 the  air4    ,even the fables of the   
ancients abound with stories about      
flying3 that  of ,dedalus and his son   
,icarius1 will occur to every reader4   
,and the  representations of the        
,,poets1 and the allusions in ,,holy    
,,writ equally  prove how natural and   
dear to the mind of man is the idea of  
possessing wings like a dove4    ,but it
 is safe enough to assert1 that         
hitherto1 all attempts at  navigating   
the air have been failures4    ,floating
 through the atmosphere in a balloon1 at
 the mercy not only of  every wind but  
of every breath of air1 is in no        
adequate  sense aerial navigation4 ,and 
,i do not hesitate to say1 that balloons
  are absolutely incapable of being     
directed4    ,all the analogies by which
 inventors have been encouraged in their
  expectations are false1 the rudders of
 ships and the tails of birds  are no   
exceptions4 ,they will never be able to 
guide balloons as  sailors do ships1 by 
a rudder1 because ships do not float    

suspended  in the water as balloons     
float in the air2 nor do birds float    
through the air in any sense4 ,they are 
not bouyant--lighter than the  element  
in which they move1 but immensely       
heavier2 besides they do not  guide     
themselves wholly by their tails4 ,we   
may depend upon it1 if we  ever succeed 
in navigating the air1 it will be by a  
strict adherence  to the principles upon
 which birds fly1 and a close imitation 
of the  means which they employ to      
effect that object4    ,it is true1 that
 in respect to the means to be employed1
 animals  designed by the ,creator for  
flight1 have greatly the advantage of   
us1  but what natural deficiencies will 
not human ingenuity supply1 and  what   
obstacles will not human skill overcome8
 ,it has already triumphed  over much   
greater than any that ,nature has       
interposed between man and  the         
pleasures of aerial communication4      
,we have to a great extent1 mastered the
 mysterious elements of nature4    ,we  

have conquered the thunderbolt and      
learned to write with the  burning fluid
 out of which it is forged4    ,we have 
converted the boundless ocean into a    
vast highway1 traversed  for our use and
 on our errands1 by the swift agent1 and
 by great ships  driven against wind and
 tide by the mighty power of steam4     
,and yet a single generation ago1 we    
knew nothing of all this1 ,our          
grand-sires would have given these      
achievements a prominent place in  the  
list of impossible things4    ,but1 do  
you say1 the ,creator never intended us 
to  fly--therefore1 it is impossible4   
,for what did the ,creator give us skill
 and boundless perseverance8  ,was it   
designed that we should swim1 more than 
that we should  furnish ourselves with  
wings and mount up as eagles8 ,we sink  
like  lead in the mighty waters1 we only
 fall a little faster through the  air4 
,still1 ,i grant that the problem of    
aerial navigation will only be  solved  
when the principles of flight are       

clearly understood1 and we  recognize   
precisely what are the obstacles which  
prevent us from  flying by artificial   
means4    ,will these obstacles prove   
insuperable8 ,it is at present believed 
by  the multitude that they will1 but ,i
 entertain a different opinion1  most   
decidedly4    ,from my earliest youth   
this subject has occupied my thoughts4  
,it  has been the study of my life1 and 
,i modestly trust that ,i have not      
questioned nature and science in vain4  
,in the first place1 ,i undertook to    
make myself familiar with the  obstacles
 to be overcome4 ,i found the greatest  
of these to be gravity4  ,i found1      
however1 that heavy fowls1 who were     
unable to rise from  the earth1 and only
 accomplished flight by taking advantage
 of an  eminence1 sustained themselves  
without difficulty when once fairly     
embarked4 ,i also found that the best   
flyers were not equal to the feat  of   
keeping me company1 when walking at my  
usual pace2 hence ,i inferred  that     

velocity was a necessary element in     
flight1 and that  gravity1 so fatal to  
human attempts to fly1 might be made a  
powerful  auxiliary when rightly used4  
,acting upon this hint1 ,i made         
experiments with heavy barn yard fowls1 
and finally constructed a light         
apparatus to be operated by myself1     
using1 principally1 my feet as a motive 
power1 which ,i repeatedly  tried with  
various and constantly increasing       
degrees of  success4    ,now ,i am      
satisfied that my system is right4 ,it  
is my sober conviction  that the time to
 realize the dream and hope of ages has 
come4  ,startling as the announcement   
may be1 ,i propose not only to make     
short  excursions through the air       
myself1 but to teach others to do the   
same4    ,yet1 knowing perfectly the    
obstacles in the way of flight1 and     
knowing  equally well how to overcome   
them1 ,i am yet well aware that ,i must 
perfect my knowledge by practice before 
entire success can be  achieved4        

,this is only reasonable4    ,how was it
 with the swimmer2 how was it with the  
agile and dexterous  skater2 how with   
the acrobat1 and what but practice has  
just enabled  ,,weston to walk one      
hundred and twelve miles in twenty-four 
hours1 and  four hundred miles in five  
days8    ,for want of a better name1 ,i 
will call the machine upon which ,i am  
to  practice1 the ,instructor4 ,it is   
simple1 but it gives the learner  just  
what he wants--an endless series of     
inclined planes4    ,it will prevent    
accidents1 and until the student has    
mastered the  mechanical movements      
necessary to flight1 will supplement his
 efforts  by partially balancing his    
weight4    ,it consists of a beam fifty 
feet long1 poised and attached by a     
universal joint to the top of a form    
post1 say twenty feet or more in        
height4 ,upon one end of this beam the  
practitioner stands1 arrayed in  his    
wings4 ,a movable weight at the other   
end completes the apparatus2  and yet   

this simple machine1 will form the      
entering wedge to aerial  navigation4   
,and now methinks ,i see you smile1 but1
 my unbelieving friends1 let me  remind 
you that ,,copernicus1 and ,,galileo1   
and ,,franklin1 and ,,fulton1  and      
,,morse1--all better men than your      
humble servant1 were laughed at  before 
me4    ,their work is done4 ,their      
monuments stand in all lands1 and yet   
one of this band of truly great and     
worthy names still lives1  and to him ,i
 am indebted for many kind and          
encouraging words4    ,it is little     
besides this that ,i ask of you4 ,the   
stock which  you are solicited to take  
in this enterprise is small4 ,but enable
 me  by your patronage to devote myself 
for a time wholly to my project4  ,see  
to it1 that ,i do not fail for want of  
support4 ,buy my little  pamphlet at its
 insignificant cost1 ask your friends to
 do so2 and  should any of you wish to  
contribute anything more to this cause1 
which ,i have made my own1 and which ,i 

am determined to push to  a triumphant  
issue1 he may be sure that he will      
receive the  acknowledgments of a       
grateful and earnest man1 who has       
himself devoted  to it the aspirations  
and efforts of a long life1 and who is  
still  willing to take all the risks of 
failure upon himself4    ,the           
undersigned would be pleased to have    
friends interested in this  subject1    
call upon him1 when the matter will be  
more fully described4    ,,robert       
,,hardley1    #ag ,,perry ,,street1 or  
#aad ,sixth ,ave41 cor4 #ith ,st4       
,illustration3 ,,the ,,aerial ,,machine4
          ,,remarks ,,on ,,the          
,,ellipsoidal ,,balloon1    ,,propelled 
,,by ,,the    ,archimedean ,screw1      
,,described ,,as ,,the ,,new ,,aerial   
,,machine1    ,,now ,,exhibiting ,,at   
,,the ,,royal ,,adelaide ,,gallery1     
,,lowther ,,arcade1 ,,strand4           
,,remarks1 c4      ,the object proposed 
in the construction of the ,machine     
which is here  presented to the public  

view1 is simply to illustrate and       
establish  the fact1 that1 by a proper  
disposition of parts and the application
  of a sufficient power1 it is possible 
to effectuate the propulsion or         
guidance of a ,balloon through the air1 
and thus to prepare the way for  the    
more perfect accomplishment of this most
 interesting and desirable  result4     
,in the contrivance of this design1 one 
of the first effects aimed  at was to   
reduce the resistance experienced by the
 ,balloon in its  progress1 which is    
greater or less according to the        
magnitude and  shape of its opposing    
surface4 ,to this intent is the peculiar
  form of the ,balloon1 which is an     
,ellipsoid or prolate  spheroid1 the    
axis of which is twice its minor        
diameter2 in  other words1 twice as long
 as it is broad4 ,by this construction  
the  opposition to the progress of the  
,balloon in the direction of either  end
 is only one half of what it would be1  
had it been a ,balloon  of the ordinary 

spherical form and of the same          
diametrical magnitude4  ,for the exact  
determination of this proportion we are 
more  particularly indebted to the      
researches of ,sir ,george ,cayley1 a   
distinguished patron of the art1 who1 a 
few years back1 instituted a  series of 
experiments with a view to ascertain the
 comparative amounts  of resistance     
developed by bodies of different forms  
in passing  through the air2 the results
 of which he communicated to the world  
in  an essay first published in the     
,mechanic's ,magazine1 and afterwards in
  a separate pamphlet4 ,according to    
these experiments it appears1 that  the 
opposition which an ellipsoid or oval   
7of the nature of the  ,balloon1 if we  
may so call it1 in the model7 is        
calculated to  encounter in proceeding  
endways through the atmosphere is only  
one-sixth of what a plane or flat       
surface of equal area with its  largest 
vertical section1 would experience at   
the same rate2 while the  resistance to 

the progress of a globe1 such as the    
usual ,balloon1 would  be one third of  
that due to a similar circular plane of 
like diameter3  shewing an advantage1 in
 respect of diminished resistance1 in   
favour of  the former figure1 to the    
extent we have above described2 an      
advantage it  enjoys along with an      
increased capacity for containing       
gas--the cubical  contents of an        
ellipsoid of the proportions here       
observed1 being exactly  double of those
 of an ordinary ,balloon of equal       
diameter1 and  consequently competent to
 the support of twice the weight4       
,independent of the advantage of reduced
 resistance in this form1 there  is     
another of nearly1 if not quite1 equal  
importance1 in the facility  it affords 
of directing its course2 an object      
scarcely1 if at all1  attainable with a 
,balloon of the usual description       
however powerfully  invested with the   
means of motion2 as any one will readily
 perceive  who has ever noticed or      

experienced the difficulty1 or rather   
the  impossibility1 of guiding a tub    
afloat in the water1 compared with the  
condition of a boat or other similarly  
constructed body1 in the same  element4 
,the efficacy of this provision and its 
necessity will appear  more forcibly    
when we observe that whenever the       
,balloon in the machine  here described 
is thrown out of its direct bearing by  
the shifting of  the net-work which     
connects it with the hoop1 or by any    
other accident  whereby its position is 
altered with respect to the propelling  
power1  its course is immediately       
affected1 and it ceases to progress in a
  straight line1 following the direction
 of its major axis1 unless  corrected by
 the intervention of a sufficient       
rudder4    ,the second object1 after    
establishing a proper form for the      
floating  body1 was to contrive a       
disposition of striking surface that    
should  be able to realise the greatest 
amount of propulsive re-action1 in      

proportion to its magnitude and the     
force of its operation1 which it  is    
possible to accomplish4 ,to shew by what
 steps and in consequence of  what      
reasoning this point was determined as  
in the plan adopted1 would  occupy      
considerably more space than the few    
pages we have to spare  would admit of  
our devoting to it4 ,suffice it to say  
that of all the  means of creating a    
resistance in the atmosphere capable of 
being  applied to the propulsion of the 
,balloon1 the ,archimedean ,screw  was  
ascertained to be undoubtedly the best4 
,it is true that by a  direct impact or 
stroke upon the air1 as for instance by 
the  action of a fan1 or the wafting of 
any flat surface at right  angles to its
 own plane1 the maximum effect is       
accomplished  which such a surface is   
capable of producing with a given power4
 ,the  mechanical difficulties1 however1
 which attend the employment of such  a 
mode of operation are more than         
sufficient to counterbalance any        

advantage in point of actual resistance 
which it may happen to  possess2 at     
least in any application of it which has
 hitherto been  tried or proposed3 so   
that here1 as in the case of ships      
propelled  by steam1 the oblique impact 
obtained by the rotation of the         
striking surface is found to be the most
 conducive to the desired  result2 and  
of these1 that arrangement which is     
termed the ,archimedean  ,screw is the  
most effective4    ,the result aimed at1
 being the development of the greatest  
amount of  re-action in the direction of
 the axis of revolution1 it is not      
enough  to have determined the general  
character of the instrument  to be      
employed2 the proper disposition or     
inclination of its parts  becomes a     
question of the first importance4       
,according as the  turns of the screw   
are more or less oblique with respect to
 the  air they strike or the axis on    
which they revolve1 more or less of the 
resistance they generate by their       

rotation becomes resolved1 as  it is    
technically expressed1 in the direction 
of the intended course3  in other words1
 converted to the purpose in view1      
namely1 the  propulsion of the ,balloon4
    ,our limited space here again       
prevents us from entering into a detail 
of the experiments by means of which the
 true solution of this  question has    
been arrived at1 and the proper angle   
determined at which  the superficial    
spiral exercises the greatest amount of 
propulsive  force of which such an      
engine is capable4 ,these experiments   
have been  chiefly carried on by ,mr4   
,smith1 the ingenious and successful    
adapter  of this instrument to the      
propulsion of steam vessels1 for a      
series of  years1 with the greatest     
care1 and at a very considerable        
expense2 and  the result of his         
experience gives an angle of about #fg  
or #fh for  the outer circumference of  
the screw1 as that productive of the    
maximum effect2 a conclusion which is   

further verified by the  experiments of 
,sir ,george ,cayley1 of ,mr4 ,charles  
,green1 the most  celebrated of our     
practical aeronauts1 and others who have
 employed  their attention upon the     
subject4 ,this conclusion requires only 
one  modification1 which ought to be    
noticed2 namely1 that in cases of       
extreme velocity1 the number of the     
angle may be still further  increased   
with advantage1 until an inclination of 
about #gc be  obtained2 when it appears 
any further advance in that direction is
  attended with a loss of power4 ,with  
these facts in view1 the impinging      
surface of the ,archimedean ,screw1 in  
the model under consideration1  has been
 so disposed as to form1 at its outer   
circumference1 an angle  of #fh with the
 axis of revolution1 gradually          
diminishing as it  approaches the       
centre1 according to the essential      
character of such a  form of structure4 
,the novelty of the application of this 
instrument to the propulsion  both of   

ships and balloons1 suggests the        
propriety of a few more  explanatory    
remarks to elucidate its nature and meet
 certain  objections which those who are
 ignorant of its peculiar qualities are 
apt to raise in respect of it4          
,previous to the adoption of this       
particular instrument1 various          
analogous contrivances had been resorted
 to in order to produce the  same       
effects4 ,of these1 examples are        
afforded in the sails of the  windmill1 
the vane of the smoke jack1 and of more 
modern introduction1  the propellers    
designed by ,mr4 ,taylor for the        
equipment of  steam-boats1 and which    
,mr4 ,green has availed himself of to   
shew  the effect of atmospheric         
re-action in directing the course of the
  balloon4 ,now all these and similar   
expedients are merely modifications  of 
the same principle1 more or less perfect
 as they more or less  resemble the     
perfect screw1 but all falling far short
 of the efficacy  of that instrument in 

its primitive character and             
construction4 ,the  reason of this      
deficiency can be readily accounted for4
 ,all the  modifications alluded to1    
which have hitherto been applied to the 
purposes of locomotion1 are adaptations 
of plane surfaces4  ,now it is the      
character of plane surfaces to present  
the  same angle1 and consequently to    
impinge upon the air with the same      
condition of obliquity throughout4 ,but 
the rate of revolution1  and            
consequently of impact1 varies according
 to the distance from the  axis2 being  
greatest at the outer edge1 and         
gradually diminishing as  it approaches 
the centre of rotation1 where it may be 
supposed to be  altogether evanescent4  
,now it is by the re-action of the air  
against  one side of the impinging      
plane1 that the progressive motion is   
determined in the opposite direction1   
which re-action is proportioned  to the 
rate of impact1 the angle remaining the 
same4 ,if then  we suppose a re-action  

corresponding to the greatest rate of   
revolution1 which is that due to the    
outermost portion of the  impinging     
surface 7that most removed from the axis
 of rotation7 we  shall have a          
progressive motion in the whole         
apparatus greater  than the rate of     
impact of the innermost or more central 
portions of the revolving plane2 and    
accordingly the re-action will be       
thereabouts transferred from the back to
 the front of the propulsive  apparatus1
 and tend to retard instead of advancing
 the progress of  the machine to which  
it is attached4 ,this inconvenience is  
felt and  acknowledged by all those who 
have employed this principle to obtain a
  progressive motion1 and accordingly a 
provision has been made against  it in  
the removal or reduction of the central 
portion  of the revolving vanes1 with a 
view to let the air escape or pass      
through as the instrument advances2 a   
provision which is certainly  effectual 
to that end1 but at the cost of the     

surface1 which is  the ultimate source  
of the required re-action4 ,all this is 
avoided  in the use of the perfect      
screw4 ,there1 the rate of rotation and 
the  angle of impact mutually           
corresponding1 may be said to play into 
each  other's hands2 the spiral becoming
 more extended as the impact becomes    
less forcible1 that is as it approaches 
the centre1 where both  altogether      
vanish or disappear2 thus obviating the 
possibility of any  interruption to the 
course of the machine from the          
contrarious impact  of the air1 however 
quick or however slow the motions1      
either of the  screw itself or of the   
machine which is propelled by its       
operation4 ,in  attestation of this fact
 and as showing the immunity of the     
perfect  screw from the disparaging     
effects experienced by the other modes  
of  accomplishing the same object1 ,i   
will only mention a circumstance        
related to me by ,mr4 ,smith himself1 to
 whom ,i am glad to acknowledge  myself 

indebted for so much valuable           
information respecting this  instrument1
 which1 by the light he has thrown upon 
its use and the  improvements he has    
introduced into its construction1 he may
 be truly  said to have made his own4   
,upon a late occasion1 when trying one  
of  the larger class of vessels which   
had just been furnished by him upon     
this principle1 some persons not        
perceiving the true nature of the       
figure employed1 contended that some    
opposition must be experienced by  the  
central portion of the screw1 which     
revolved so much less rapidly  than the 
rate of the ship itself4 ,in order to   
convince them of their  error1 ,mr4     
,smith caused a portion of the surface  
in question1 next the  axis1 to a       
certain distance1 to be cut away1       
leaving an opening1 by  which1 for the  
water to escape4 ,the result was1       
immediately the loss  of one mile an    
hour in the rate of the ship2 thus      
shewing that even  the most apparently  

feeble portion of the impinging surface 
of this  instrument contributes1 in its 
degree1 to the constitution of the      
aggregate force of which it is          
productive4    ,this peculiarity of     
construction is the main cause of the   
advantage  which the ,archimedean ,screw
 possesses over all its types or        
imitations2 but it is not the only one4 
,the entirety or  unbroken continuity of
 its surface is another1 not much less  
influential4 ,the value of this will be 
the more readily appreciated  when we   
consider that air1 unlike water and     
other non-elastic fluids1  undergoes a  
rarefaction or impoverishment of        
density1 and consequently  of resisting 
power1 accordingly as it is swept away  
by the rapid  passage of impinging      
planes2 the parts immediately behind1   
and  to a considerable distance1 being  
thereby relieved from the support  they 
had previously experienced1 and         
extending 7and consequently  becoming   
thinner7 in order to fill up the space  

thus partially cleared  away4 ,now it is
 evident that if other planes be brought
 into operation  in the parts of the    
atmosphere thus impoverished1 before    
they have  had time to recover their    
pristine or natural density1 they will  
of necessity act with diminished vigour2
 the resistance being ever  proportioned
 to the density of the resisting medium4
 ,this is the  condition into which1    
more or less1 all systems of revolving  
planes  are necessarily brought1 that   
consist of more than one2 and is a      
grand cause of the little real effect   
they have been made capable  of         
producing1 whenever tried4 ,the nature  
of this objection1 and the  extent to   
which it operates1 will appear most     
strikingly from the  following fact4    
,mr4 ,henson's scheme of flight is      
founded upon the  principle of an       
inclined plane1 started from an eminence
 by an  extrinsic force1 applied and    
continued by the revolution  of         
impinging vanes1 in form and number     

resembling the sails of a  windmill4 ,in
 the experiments which were made in this
 gallery with  several models of this   
proposed construction1 it was found that
 so far  from aiding the machine in its 
flight1 the operation of these  vanes   
actually impeded its progress2 inasmuch 
as it was always  found to proceed to a 
greater distance by the mere force of   
acquired  velocity 7which is the only   
force it ever displayed71 than when  the
 vanes were set in motion to aid it--a  
simple fact1 which it is  unnecessary to
 dilate upon4 ,it is to the agency of   
this cause1 namely1  the broken         
continuity of surface1 that1 ,i have no 
doubt1 is also to be  ascribed the      
failure of the attempt of ,sir ,george  
,cayley to propel a  ,balloon of a      
somewhat similar shape to the present1  
which he made at  the ,polytechnic      
,institution a short while since1 when  
he employed  a series of revolving      
vanes1 four in number1 disposed at      
proper  intervals around1 but which were

 found ineffectual to move it4 ,had     
these separate surfaces been thrown into
 one1 of the nature  and form of the    
,archimedean ,screw1 there is little    
doubt that the  experiment would have   
been attended with a different result4  
,in  accordance with the principles here
 illustrated1 the ,archimedean  ,screw  
properly consists of only one turn2 more
 than one being  productive of no more  
resistance1 and consequently            
superfluous4 ,a  single unbroken turn of
 the screw1 however1 when the diameter  
is of  any magnitude1 would require a   
considerable length of axis1 which in   
its adaptation to the ,balloon1 would be
 practically objectionable2  accordingly
 two half turns1 nearly equivalent in   
power to one  whole turn1 has been      
preferred2 as in most instances it has  
been by  ,mr4 ,smith1 himself1 in his   
application of it to the navigation of  
the  seas1    ,indeed1 in all other     
respects1 except the nature of its      
material1 the  screw here represented is

 exactly analogous to that used by ,mr4 
,smith  in its most perfect form1 having
 been1 in fact1 designed1 and in part   
constructed under his own supervision4,a
    ,the model upon which these         
principles have been now1 for the first 
time1 successfully1 at least1 tried in  
the air1 is constructed upon  the       
following scale4 ,the ,balloon is1 as   
before stated1 an ellipsoid  or solid   
oval2 in length1 #ac feet #f inches1 and
 in height1 #f feet #h  inches4 ,it     
contains1 accordingly1 a volume of gas  
equal to about #cbj  cubic feet1 which1 
in pure hydrogen1 would enable it to    
support a  weight of twenty-one pounds1 
which is about its real power when      
recently inflated1 and before the gas   
has had time to become  deteriorated by 
the process of endosmose4,b ,the whole  
weight  of the machine and apparatus is 
seventeen pounds2 consequently there  is
 about four pounds to spare1 in order to
 meet this contingency4    ,footnote ,a3
 ,the frame was made at ,mr4 ,smith's   

request1 by ,mr4  ,pilgrim1 of the      
,archimedes2 the original experimental  
vessel in which  this mode of propulsion
 was first tried upon the large scale4  
,mr4  ,pilgrim has been long versed in  
all that relates to the mechanism of    
this instrument1 and is indeed a most   
expert and ingenious artist4            
,footnote ,b3 ,endosmose is that        
operation by which gases of  different  
specific gravities are enabled1 or      
rather forced to come  together through 
the pores of any membranous or other    
flexible  covering by which it is sought
 to restrain them4 ,as above referred   
to1  it is the introduction of          
atmospheric air into the body of the    
,balloon  through the pores of the silk1
 however accurately varnished1 by which 
the purity of the hydrogen gas is       
contaminated1 and its buoyant power     
ultimately exhausted ,this it is        
impossible to prevent by any process1   
except the interposition of a metallic  
covering2 as for  instance1 by gilding  

the ,balloon1 which would be effectual  
could it be contrived to endure the     
constant friction and bending of  the   
material itself4    ,beneath the centre 
of the ,balloon1 and about two-thirds of
 its length1  is a frame of light wood1 
answering to the hoop of an ordinary    
,balloon2 to which are attached the     
cords of the net which encloses the     
suspending vessel1 and which serves to  
distribute the pressure of the  appended
 weight equally over its whole surface1 
as well as to form an  intermediate     
means of attachment for the rest of the 
apparatus4 ,this  consists of a car or  
basket in the centre2 at one end the    
rudder1 and  at the other the           
,archimedean ,screw4 ,the car is about  
two feet long  and eighteen inches      
broad1 and is laced to the hoop by      
cords1 which  running through loops     
instead of being fastened individually1 
allow of  unlimited play1 and equalize  
the application of the weight of the car
  to the hoop1 as of the whole to the   

,balloon above4 ,the ,archimedean       
,screw consists of an axis of hollow    
brass tube eighteen inches in  length1  
through which1 upon a semi-spiral of #ae
 of inclination1 are  passed a series of
 radii or spokes of steel wire1 two feet
 long1 7thus  projecting a foot on      
either side7 and which being connected  
at their  outer extremities by two bands
 of flattened wire1 form the frame work 
of the ,screw1 which is completed by a  
covering of oiled silk cut into  gores1 
and tightly stretched1 so as to present 
as nearly uniform a  surface as the     
nature of the case will permit4 ,this   
,screw is supported  at either end of   
the axis by pillars of hollow brass tube
 descending  from the hoop1 in the lower
 extremities of which are the holes in  
which the pivots of the axis revolve4   
,from the end of the axis which  is next
 the car1 proceeds a shaft of steel1    
which connects the  ,archimedean ,screw 
with the pinion of a piece of spring    
machinery  seated in the car2 by the    

operation of which it is made to        
revolve1  and a progressive motion      
communicated to the whole apparatus4    
,this  spring is of considerable power  
compared with its dimensions1 being     
capable of raising about #de pounds upon
 a barrel of four inches  diameter after
 the first turn1 and gradually          
increasing as it is wound  up4 ,it      
weighs altogether1 eight pounds six     
ounces4    ,the rudder is a light frame 
of cane covered with silk1 somewhat of  
the  form of an elongated battledoor1   
about three feet long1 and one foot     
wide1 where it is largest4 ,it might be 
made considerably larger if  required1  
being exceedingly light and yet         
sufficiently strong for any  force to   
which it could be subjected4 ,it weighs 
altogether only two  ounces and a half4 
,this instrument possesses a double     
character4  ,besides its proper purpose 
of guiding the horizontal course of the 
,balloon1 it is capable of being applied
 in a novel manner to its  elevation or 

depression1 when driven by the          
propulsive power of  the ,screw4 ,being 
so contrived as to be capable of being  
turned  flat1 and also directed upwards 
or downwards as well as to the  right or
 left1 it enables the aeronaut to       
transfer the resistance of  the air1    
which1 in any inclined position1 it must
 generate in its  passage1 to any side  
upon which he may desire to act1 and    
thus give a  determination to the course
 of the ,balloon in the opposite        
direction4  ,this will appear more clear
 as well as more certain when we        
consider1  that the aerial vessel being 
in a state of perfect equipoise1 as  it 
ever must be when proceeding on the same
 level1 the slightest  alteration in its
 buoyancy is sufficient to send it to a 
considerable  distance either up or down
 as the case may be3 the rejection of a 
pound of ballast1 or of an equivalent   
amount of gas1 being enough to  conduct 
the aeronaut to the extremest limits of 
his desires in either  direction1       

whatever may be the size of his         
,balloon4 ,now a resistance  equal to   
many pounds is attainable by an inclined
 plane of even  moderate dimensions when
 propelled even with moderate velocity2 
and  being readily governed by the mere 
inclination of the impinging plane  at  
the will and by the hand of the aerial  
voyager1 it will be in his  power to    
vary the level of his machine with very 
considerable nicety2  enabling him to   
approach the surface of the earth1 or in
 a gentle  curve to sweep away from its 
occasional irregularities1 and proceed  
to  a very considerable elevation       
without interrupting the progress of his
  course1 and1 what is of more          
importance1 without sacrificing any part
  of his resources in gas or ballast1   
upon the preservation of which the      
duration of his career so entirely      
depends4 ,these properties of the       
rudder it is not possible to display in 
the present exhibition1 owing  to the   
confined nature of the course which it  

is necessary to pursue2  but they were  
sufficiently tested in the preliminary  
experiments at  ,willis's ,rooms1 where 
the space being larger1 a circular      
motion was  conferred upon the machine  
by connecting it with a fixed centre    
round  which it was thus made to        
revolve1 without the necessity of       
confining  it to the one level4    ,the 
rate of motion which the ,balloon thus  
equipped is capable of  accomplishing   
varies according to the circumstances of
 its propulsion4  ,when the ,archimedean
 ,screw precedes1 the velocity is less  
than when  it is made to follow1 owing  
to the reaction of the air in the former
  instance against the car1 the under   
surface of the balloon1 and other       
obstacles1 by which its progress is     
retarded4 ,again1 when the cord  upon   
which it travels is most tense and free 
from vibration1 the rate  is found to be
 considerably accelerated1 compared with
 what it is when  the contrary          
conditions prevail4 ,but chiefly is its 

speed affected  by the proper ballasting
 of the machine itself1 upon which1     
depends the friction it encounters from 
the cord on which it travels4  ,under   
ordinary circumstances it proceeds at a 
rate of about four miles  an hour1 but  
when the conditions alluded to have been
 most favourable1  it has accomplished a
 velocity of not less than five2 and    
there is no  doubt that were it         
altogether free from restraint1 as it   
would be in  the open air1 with a hand  
to guide it1 its progress would be      
upwards  of six miles an hour4          
,having now1 ,i trust1 sufficiently     
explained the principles exemplified  in
 the model here described1 it may be    
expected that ,i should add a  few words
 regarding their reduction into practice
 upon a larger scale  and in the open   
air1 with such difficulties to contend  
with as may be  expected to be          
encountered in the prosecution of such a
 design4 ,in the  first place1 however1 
it will be necessary to disabuse the    

public mind  of some very prevailing    
misconceptions with respect to the      
conditions  of a ,balloon exposed to the
 action of the winds1 pursuing its      
course under the exercise of an inherent
 propulsive power4 ,these               
misconceptions1 which1 be it observed1  
are more or less equally  participated  
in by the scientific as by the ignorant1
 when devoid  of that practical         
experience which is the basis of all    
aeronautical  proficiency1 are of a very
 vague and general character1 and       
consequently not very easy accurately to
 define4 ,in order1 therefore1  to make 
sure of meeting all the objections and  
removing all the doubts  to which they  
are calculated to give rise1 it will be 
advisable1 even  at the risk of a little
 tediousness1 to separate them into     
distinct  questions and treat them      
accordingly4    ,one of the most        
specious of these misconceptions regards
 the effects  of the resistance of the  
atmosphere upon the figure of the       

,balloon  when rapidly propelled through
 the air1 whereby it is presumed its    
opposing front will be driven in1 and   
more or less incapacitated from         
performing the part assigned to it2     
namely1 to cleave its way with the      
reduced resistance due to its proper    
form4 ,to obviate1 this imagined        
result1 various remedies have been      
proposed--such as1 to construct  that   
part of the machine of more solid       
materials than the rest1 or  else 7as   
suggested by one of the most scientific 
and ingenious of  those who have devoted
 their attention to the theory of aerial
  navigation71 to subject the gaseous   
contents of the ,balloon to such a      
degree of artificial condensation by    
compression1 as shall supply  from      
within a force equal to that from       
without2 adopting1 of course1  materials
 of a stronger texture than those at    
present in use1 for the  construction of
 the balloon4 ,now the contingency      
against which it is  here sought to     

provide1 and which ,i grant is a very   
reasonable one to  anticipate1 has      
nevertheless no real existence in       
practice2 at least  in such a degree as 
to render it necessary to have recourse 
to any  particular expedient for its    
prevention4 ,taking it for granted that 
the hypothesis in which it is involved  
is founded upon a presumed  analogy with
 a ,balloon exposed to the action of the
 wind while in a  state of attachment to
 the earth1 ,i would first observe that 
the cases  in question1 however         
apparently analogous1 are in reality    
essentially  dissimilar4 ,in the one    
case 7that where the ,balloon is        
supposed to be  attached to the earth7  
all the motion1 and consequently all the
  momentum1 is in the air2 in the other 
case 7where the ,balloon  is supposed to
 be progressive71 it is in the          
constituent particles of  the machine   
itself and of its gaseous contents4 ,and
 this momentum1  which is ever          
proportioned to the rate of its motion1 

and1  consequently1 to the amount of    
resistance it experiences1 is amply     
sufficient to secure the preservation of
 the form of its opposing  front1       
however partially distended1 and        
whatever the velocity with  which it    
might happen to be endowed4             
,independently1 however1 of this        
corrective principle1 another1 equally  
efficacious is afforded in the  buoyant 
power of the included gas1 which1       
occupying all the upper part  of the    
,balloon so long as it is in a condition
 to sustain itself in  the air1 and     
generally extending to its whole        
capacity1 presses from  within with a   
force far greater than any it could     
experience from  the external impact of 
the atmosphere1 and sufficiently resists
 any  impression from that quarter which
 might tend to impair its form4  ,to    
what extent this is effective1 will     
appear more clearly when we  observe    
that in any balloon inflated1 it is the 
sides of the  distended globe that bear 

out the weight of the appended cargo1   
through the intervention of the network2
 a weight only limited by the           
sustaining power of the machine itself1 
and in the case of the great  ,vauxhall 
or ,nassau ,balloon1 amounting to more  
than two tons1 and  consequently        
pressing with a force far exceeding any 
that could arise  from the impact of the
 air at any rate of motion it could ever
 be  expected to accomplish4 ,and this  
statement1 which represents the         
theoretical view of the question1 is    
fully borne out by the real             
circumstances of the case as they appear
 in practice4 ,so far  from justifying  
the apprehensions of those who conceive 
that the  front of the ,balloon would be
 disfigured by its compulsory           
progression through the air1 the result 
is exactly the reverse2 the  only       
tendency to derangement of form         
displaying itself in the part  behind1  
where the rushing in of the atmospheric 
medium to fill  the place of the        

advancing body 7in the nature of an     
eddy1  as it is termed in water71 might 
and no doubt would1 to some extent      
7though perhaps but slightly7 affect the
 figure of that part1 in a  manner1     
however1 calculated rather to aid than  
to impair the general  design in view1  
,another error of more universal        
prevalency1 because of a more           
superficial character1 regards the      
condition of the ,balloon as  affected  
by the currents of air1 in and through  
which it might have  to be propelled4   
,the arguments founded upon such a view 
of the case1  generally assume some such
 form as the following--,it is true you 
can  accomplish such or such a rate of  
motion2 but that is only in a room1     
with a calm atmosphere1 or with a       
favourable current of wind4 ,in the     
open air1 with the wind at the rate of  
twenty or thirty miles an hour1  your   
feeble power would be of no avail4 ,you 
could never expect to  direct your      
course against the wind1 and if you were

 to attempt  it and the wind were       
strong1 you would inevitably be blown to
 pieces  by the force of the current4   
,now this argument is equally nought    
with  the preceding4 ,the condition of  
the ,balloon1 as far as regards the     
exercise of its propulsive powers1 is   
precisely the same whether the  wind be 
strong or gentle1 with it or against it4
 ,in neither case would  the ,balloon   
experience any opposition or resistance 
to its progress  but what itself1 by its
 own independent motion1 created2  and  
that opposition or resistance would be  
exactly the same in  whatever direction 
it might be sought to be established4   
,the ,balloon1  passively suspended in  
the air1 without the exercise of a      
propulsive  power1 experiences no       
effects whatever from the motion of the 
atmosphere in which it is carried1      
however violent2 and the  establishment 
of such a propulsive power could never  
subject it to  more than the force      
itself1 with which it was invested4 ,the

 way  which the ,balloon so provided    
would make through the air would always 
be the same1 in whatever direction1 or  
with whatever violence the wind  might  
happen to blow2 and the condition of the
 ,balloon would always be  the same that
 was due to its own independent rate of 
motion1  without regard to any other    
circumstances whatever4 ,if it was      
furnished with the means of             
accomplishing a rate of motion equal to 
ten miles an hour1 it would experience a
 certain amount of atmospheric          
resistance due to that rate2 and this   
amount of resistance with  all its      
concomitant consequences1 neither more  
nor less1 would it  experience1 whether 
it endeavoured to make this way against 
a  wind blowing at the rate of #ajj     
miles an hour1 or with the same  in its 
favour4 ,the result1 so far as regards  
its distance from the  place of         
starting1 would1 ,i grant1 be very      
different2 but at present  we are only  
considering the conditions of its motion

 through the  air1 and these1 ,i repeat1
 would be the same whatever the rate  or
 course of the wind2 so that all        
speculations on this score  must resolve
 themselves into questions of quantity1 
not of  quality1 in the effect sought to
 be accomplished3 in other  words1 all  
consideration of the rate of the wind   
must be left out of  the argument1      
except1 in so far as it shall be taken  
to regulate the  limit which shall be   
assigned to the rate of the aerial      
machine1 as  sufficient to justify its  
claims to the title of a successful mode
 of  navigating the skies4,a            
,footnote ,a3 ,the condition of a       
,balloon propelled by machinery is very 
analogous to that of a boat in the water
 driven by oars or paddles4  ,suppose   
such a boat to be rowing or paddling up 
a river against the  stream1 if a piece 
of cork be thrown overboard it appears  
to be  carried away with the current4   
,but this is delusive2 it is the boat   
alone which really moves away from the  

cork4 ,for if the boat be  left to its  
own course1 both it and the cork will   
float down together2  and if the use of 
the oars or paddles be resumed1 the     
distance  between the boat and the cork 
will proceed to develope itself exactly 
according to the rate of the boat1      
without any regard to that  of the      
stream4 ,if the stream be excessively   
rapid1 the boatsmen  will appear to be  
exercising very great force to enable   
them to stem  the torrent and avoid     
being carried backward4 ,now the        
resistance which  they experience and   
all its attendant effects are only those
 which  they create for themselves1 and 
which they would experience in exactly  
the same degree were they to endeavour  
to move at the same rate  in calm water 
or with the current in their favour4 ,if
 the current be  at the rate of ten     
miles an hour and they are just able to 
maintain  their place1 they are         
proceeding at the rate of ten miles an  
hour1 and  they experience the          

opposition due to that rate of motion2  
precisely  the same as they would       
experience if they sought to accomplish 
the  same rate of motion under any other
 circumstances4 ,and if the current     
were #ajj miles an hour1 they would     
suffer no more from endeavouring to  go 
against it1 with the force just ascribed
 to them1 than if they  were to exercise
 the same force in any other direction1 
or in a water  perfectly tranquil4      
,apply this reasoning to the case of a  
,balloon  propelled by machinery1 and   
much of the obscurity in which it is    
involved will disappear4    ,with these 
conditions established1 it will now be  
seen that we have  nothing to consider1 
in discussing the probable success of   
any scheme  of aerial navigation with   
the aid of the ,balloon 7so far as its  
mere  movements are concerned7,a except 
the actual rate of motion  which it is  
competent to accomplish2 whether or not 
it be sufficient  to meet the exigencies
 of the case as they may happen to be   

estimated4  ,that its capabilities in   
that respect1 be displayed within a     
room1 or  in a calm atmosphere1 or under
 what may be called the most favourable 
circumstances1 has nothing in it to     
disparage or affect the general         
question4 ,whatever it can do there1 it 
can do the same in a  hurricane2 and the
 only real question is1 whether1 what it
 can  accomplish in respect of rate1 is 
enough to answer the purpose in  view4  
,footnote ,a3 ,i have said so far as its
 mere movements are concerned2  because 
the complete success of the scheme1 how 
far it is an available  and satisfactory
 mode of transport1 depends upon other  
conditions  besides the accomplishment  
of a given rate of motion--as for       
instance1  whether it be safe1 or       
practicable1 or consistent with a due   
preservation of the buoyancy of the     
,balloon1 so as to allow of  its being  
employed in voyages of sufficient       
distance and duration1  or capable of   
being worked at moderate cost1 or       

whether it leave  sufficient allowance  
for cargo2 with many others of less     
striking  importance1 which the         
practical aeronaut will readily suggest 
for  himself4    ,the model we have been
 just describing is capable as we have  
seen1 of  accomplishing a rate of about 
six miles an hour4 ,now the resistance  
to  the progress of a ,balloon varies as
 the squares of the velocities or  rates
 of motion4 ,accordingly1 for the same  
,balloon to accomplish  twice the speed1
 or twelve miles an hour1 it would be   
necessary to be  provided with four     
times the power4 ,thus as the spring    
power employed  in the model is equal to
 a weight of #de pounds1 upon a barrel  
of four  inches in diameter1 it would   
require one competent to raise #ahj     
pounds  on the same sized barrel1 to    
enable it to propel the same ,balloon at
  double the present rate4    ,but with 
regard to ,balloons of different sizes  
and of the same shape1  the power       
required to produce the same rate of    

motion1 would be as  the squares of     
their respective diameters3 for the     
power is as the  resistance1 the        
resistance as the surface1 and the      
surface follows the  proportion just    
assigned4 ,in order1 therefore to propel
 a ,balloon  of the same form and twice 
the diameter1 at the same rate1 it would
  require a force of four times the     
amount4    ,now to apply this to the    
consideration of a ,balloon of superior 
magnitude1 let us assume one of #ajj    
feet in length1 and fifty feet in       
height4 ,the buoyant power of such a    
machine1 or the weight it would  carry1 
supposing it inflated with gas of the   
same specific gravity1  compared with   
that of the model1 would be as the cubes
 of their  respective diameters2 or in1 
about1 the ratio of #dbj to one4 ,such a
  ,balloon1 therefore1 so inflated1     
would carry a weight of about #hgjj     
pounds1 or above three tons and three   
quarters4 ,as1 however1 it would  be    
very expensive to inflate such a vessel 

with pure hydrogen gas1 it  would be    
advisable to found our calculations upon
 the use of coal gas2  under which      
circumstances the weight it would carry 
would be limited  to about three tons4  
,deducting from this1 one ton for the   
weight of  the ,balloon itself and its  
necessary equipments1 there would remain
  two tons1 or about #dejj pounds1 to be
 devoted to the power1 whatever  it     
might be1 by which the machinery was to 
be moved1 and the living  cargo it might
 have to carry4 ,nor let the reader be  
surprised at  the magnitude of the      
figures we are here employing1 as if it 
were  something extraordinary or beyond 
the power of man to accomplish4 ,the    
dimensions and power we have here       
assumed is very little greater than     
those of the great ,vauxhall ,balloon1,a
 and considerably less than  some of    
,montgolfires1 or ,fire-balloons1 which 
were first  employed4    ,footnote ,a3  
,the height of the ,vauxhall ,balloon is
 about eighty feet1  its breadth about  

fifty4 ,it contains #hejjj cubic feet of
 gas1 and  supports a weight of upwards 
of two tons4    ,now the resistance     
which such a ,balloon as ,i have here   
described would  experience in its      
passage through the air1 and            
consequently the power  it would require
 to establish that resistance compared  
with those  of the model1 we have said  
would be as the squares of their        
respective diameters1 or in1 about1 the 
ratio of only fifty-six to  one2 in     
other words1 whatever force it would    
take to propel the model  at any given  
rate1 it would require just fifty-six   
times the power  to accomplish the same 
result with the large ,balloon we have  
been  describing4    ,in order to       
ascertain precisely what this power     
would be in any given  instance1 it only
 remains to find an expression for the  
spring power  with which we have been   
hitherto dealing1 that shall be more    
generally  comprehensible4    ,this we  
shall do by a comparison with the power 

of steam1 according to  the usual mode  
of estimating it2 that is1 reckoning a  
one-horse power  to be equal to the     
traction or draught of #cb1jjj lbs4     
through the  space of one foot in a     
minute4 ,according to this scale1       
observing the  corresponding conditions 
of the spring--namely1 the weight it    
balances  on the barrel1 7answering to  
the force of traction7  #de lbs41 the   
circumference of the barrel 7answering  
to the space traversed7  one  foot1 and 
the time of uncoiling for each turn1    
7answering to the rate  of the          
operation7 say1 three seconds and a     
half--we find the power of  the spring  
employed in the propulsion of the model1
 to be as nearly as  possible the       
forty-second part of the power of one   
horse2 from whence  it is easy to deduce
 the conditions of flight assignable to 
the same1  and to different sized       
,balloons of the same shape1 at any     
other degree  of speed4 ,assuming1 for  
instance1 a ,balloon of #ajj feet in    

length and  #ej feet in height1 and     
proposing a rate of motion equal to #bj 
miles an  hour1 we have1 in the first   
instance1 the power required to propel  
the model at that rate1 compared with   
that already ascertained for a  velocity
 of six miles an hour1 in the ratio of  
the squares of the  two velocities1 as  
nearly ten to one2 that is1 ten         
forty-seconds1  or about one-fourth of a
 horse power4 ,to apply this to the     
larger  ,balloon1 we must take the      
squares of their respective diameters2  
which  being nearly in the ratio of #ef 
to #a1 gives an amount of #ef times     
one-fourth or about #ad horses1 as the  
sum of the power required4    ,from what
 particular source the power to be      
employed in the propulsion  of the      
,balloon should be deduced1 is not      
indeed a question without  some         
difficulties and doubts in the          
determination4 ,to all the moving       
powers at present before the world some 
objections apply which  disparage their 

application1 or altogether exclude them 
from our  consideration4    ,the power  
of the coiled spring is too limited to  
be employed upon  a larger scale4 ,the  
use of the steam-engine is accompanied  
with a  gradual consumption of the      
resources of the ,balloon in ballast1   
and  consequently in gas1 the one being 
exactly answerable to the other1  and is
 therefore not calculated for voyages of
 long duration4 ,human  strength appears
 to be too feeble for great results1 and
 moreover1  requires repose2 which      
reduces the amount assignable to each   
man to a  fraction of its nominal value4
 ,of electro-magnetism as yet we know   
too little to enable us to pronounce    
upon it with certainty4 ,of the         
remaining powers known only one is worth
 mentioning in connexion  with this     
subject1 namely1 the elastic force of   
air2 and this ,i only  mention because  
it has been taken up by one whose       
authority in these  matters is          
deservedly entitled to much weight1 and 

who entertains  great hopes of making it
 ultimately subservient to the purpose  
in  view4    ,but although none of these
 powers1 in their present state1 be so  
perfectly adapted to the propulsion of  
the ,balloon as to leave  nothing       
further to desire1 yet are some of them 
so far applicable as1  undoubtedly1 to  
enable us to accomplish1 by their means1
 a very large  amount of success4 ,a    
steam engine of the power required1     
namely1 equal  to fourteen horses1 could
 be easily constructed1 far within the  
limits  of weight which we have at our  
disposal upon that account in the       
,balloon under consideration1 or even in
 one much smaller2 and recent           
improvements have so far reduced the    
amount of coal required for its         
maintenance1 that perhaps as long a     
voyage could be made by means of  it    
now1 as would be expected or required4  
,even human strength1 by  a certain mode
 of applying it1 might be made effectual
 to the  accomplishment of a very       

sufficient rate of motion1 say fourteen 
or  fifteen miles an hour1 for1         
continuously1 as long a period as the   
natural strength of man1 moderately     
taxed1 could endure1 and which we  may  
reckon at twelve hours4    ,it is true  
that neither the velocity here quoted1  
nor that before  assumed is so great as 
to enable the aeronaut to compete with  
some of  the modes of transit employed  
on the surface of the earth2 as1 for    
instance1 the railroads1 where #be miles
 an hour is not an unusual  speed4 ,yet 
is not the aerial machine which could   
command such a  rate of motion to be    
despised1 or set aside as inferior in   
actual  accomplishments to what is      
already at our disposal2 for it must not
  be lost sight of1 that railroads1 or  
terrestrial roads of every  description1
 must ever be limited in their extent   
and direction1 and  travelling on them1 
however perfectly contrived1 subject to 
deviations  and interruptions1          
particularly in passing from one country

 to another  beyond the seas1 which if  
taken into account1 would reduce the    
apparent estimate of their rates1       
considerably under the lowest of  those 
assigned to the ,balloon in the previous
 calculation2 and at all  events1 by    
sea1 much less1 under the most          
favourable circumstances is  the        
ordinary rate of ships4    ,but1 it may 
be observed1 we are here counting upon a
 rate of motion as  established1 which  
is only effectual to that extent in the 
absence of  contrary currents of wind4  
,this is true2 nevertheless it is no bar
 to  the use which might be made of the 
aerial conveyance so furnished1 nor  any
 disparagement to the advantages which  
might be drawn from it2  for not only   
does the aeronaut possess the means of  
choosing1 within  certain limits1 the   
currents to which he may please to      
commit himself1  and of which1 abundance
 of every variety is sure to be met with
 at  some elevation or other in the     
atmosphere1 but1 as in all general      

arguments1 where the conditions are     
equally applicable to both sides  of the
 question1 they may be fairly left out  
as neutralising each  other1 so1 here it
 must not be forgotten1 that the        
currents in  question1 being altogether 
indeterminate1 and equally to be        
expected  from all quarters1 an equal   
chance exists of advantages to be       
derived1  as of disadvantages to be     
encountered from their occurrence2 and  
that1  even without the means of making 
a selection1 the admitted laws of       
reasoning would justify us in           
considering the chances of the latter   
to be fully counterbalanced by those of 
the former4 ,it is enough1 for  moderate
 success at least1 if1 possessing the   
power of avoiding the  bad1 and of      
availing himself of the good1 the       
aeronaut be furnished  with the means of
 making a sufficient progress for       
himself when the  atmosphere is such as 
neither to favour nor to obstruct him2  
and in  this condition ,i humbly        

conceive he would be placed1 with even a
  less rate of motion than that which we
 have before assigned1 and  confidently 
reckon upon being able to accomplish4   
,,finis4