On Aerial Navigation. 7 



fuct nation of the atmosphere. We might as well attempt to 

 direct an atom in the ocean ; all seamen know that a large 

 vessel has a command of the water, and a steadiness, which 

 cannot be expected in a boat. He tolks of acres of canvass, 

 and proposes a subscription ; but this is wholly premature, the 

 true theory mav yet require years for its development. 



5. This last philosopher has neglected an obvious conside- 

 ration : When the cayoe hollowed from one tree was found too 

 small, mankind formed a vessel of united ])Ianks. Here we 

 must not attempt lurther to enlarge one balloon, but should 

 apply several to elevate a platform'. If, tor instance, an isosce- 

 les triangle had one balloon at the vertex, and one at each 

 angle of'^the base, the whole might occupy such a space as 

 would have a sufficient hold upon the air, and be very con- 

 venient for direction. By such a plan of union, the whole 

 macliine may take any form which we wish ; whereas the othei* 

 must be bulky and "^inconvenient, and always more or less 

 spherical. There will be difficulties in practice which in- 

 genuity must surmount ; one corner, for instance, may have a 

 greater tendency to rise than another. Perhaps this may be 

 obviated by pipes of communication, or by a car or weight 

 connected by strings with each corner of the platform; so that 

 the string attached" to any corner being pulled, will bring the 

 weight nearer to that corner and lower it. The machme 

 should be well adjusted before it is set at liberty; any viscid 

 fluid will indicate subsequent changes in the horizontahty. 



6. There is one obvious difficulty, which has long nnpeded 

 our progress. The whole machine being of equal specific 

 gravity with the atmosphere, is in a state ot indifference as to 

 position ; any part may lie before or behind, while the whole 

 is carried forward with the current, and tends to move with 

 the same velocity. We even observe that balloons are in a 

 constant state of rotation, alternately in one direction and the 

 opposite. This can only be obviated by increasing tiie inertia 

 of some particular part," or by connecting the machine with a 

 distant stratum of the air. Perhaps, if a weight hung down 

 to a considerable distance, suspended Irom the base ol the 

 triangular platibnn above mentioned, in such case Uie tore 

 part of the machine would be carried forward in the direction 

 of the wind. The whole machine would then tend to main- 

 tain a definite position in respect of the atmospheric current, 

 which is "the first essential point to be established, belore any 

 attempt is made to modifv its direction. Seamen m the deep 

 water brin- a boat to anchor, by letting out a heavy shot to 

 a considerable depth. It will be a matter ot experiment, 

 whether tlieit- siioiild bc several weights hanging to di leicnt 



depths. 



