RECENT PROGRESS IN AERIAL NAVIGATION. 299 



Wilcox rise crowded in the cage, surrounded by forty-seven balloons 

 fastened to it, with astonishing coolness, nodding his head to express 

 his satisfaction and composure. After all, he could not rise above 

 ninety-seven feet, according to the measures taken by two other gen- 

 tlemen of the Philosophical Academy. He was at least five minutes 

 in the air, but, perceiving the wind to blow from the east and drive 

 him toward the Scoulquille [Schuylkill], he was frightened, and, agree- 

 ably to his instructions, made several incisions with a knife in three of 

 the balloons. This was not sufficient, though we saw him descend a 

 little. He pierced three more, and, seeing the machine did not come, 

 his fear increased. He cut five more in the greatest haste, and, unfor- 

 tunately, all on the same side. He was then seen to tack about (cha- 

 virer), and, as if he had slid down (coide bas), he fell on the edge of a 

 ditch and a finse [fence], as they call the inclosures. Dr. Jaune ran 

 up ; the poor man had sprained his wrist, but received no other 

 accident." 



No sooner was the fact demonstrated that men could safely rise 

 into the air at will, than inventors began to devise plans for directing 

 aerial machines. So long as the balloon is completely at the mercy of 

 the wind, it is practically useless as a means of conveyance. On rising 

 high above the ground the direction of aerial currents is often found 

 to differ greatly from that of the surface-currents. Rising above the 

 clouds, the aeronaut may lose sight of the earth and be carried at a 

 rate of which he is totally unconscious, there being no means of meas- 

 uring his speed when borne along with a current to which the balloon 

 opposes no sensible resistance. By noting the times and places of as- 

 cent and descent, the rate has been estimated to exceed that of our 

 fastest railroad-trains ; and more than one aeronaut has lost his life by 

 being carried out to sea. In the early part of 1784 M. Robert, the 

 colleague of Charles, attempted the propulsion of a balloon by means 

 of oars, but in vain. He subsequently tried artificial wings, but with 

 no better success. M. Blanchard, who crossed the English Channel 

 in 1785 with Dr. Jeffries, tried a variety of similar devices without 

 success. 



For the directing of balloons one of the first suggestions based on 

 correct principles was offered by Francis Hopkinson. In a letter to 

 Franklin, dated at Philadelphia, May 24, 1784, he recommends that 

 the balloon shall be made oblong instead of spherical, and provided 

 with a large and light wheel at the stern. " This wheel should consist 

 of many vanes or fans of canvas, whose planes should be considerably 

 inclined with respect to the plane of its motion, exactly like the wheel 

 of a smoke-jack. If the navigator turns this wheel swiftly round by 

 means of a winch, there is no doubt but it would (in a calm at least) 

 give the machine a progressive motion, upon the same principle that a 

 boat is sculled through the water." (Sparks's " Life and Works of Ben- 

 jamin Franklin," vol. x, p. 93.) This remarkable suggestion by Hop- 



