Joe was not long in satisfying himself that it was 

 the elasticity of the air being cut off from escape by 

 the touchhole, and the tight piston made by the 

 buckskin patch on the bullet, that caused the bullet 

 to rise; but it did not to his mind account for firing 

 the powder. Thinking it possible there might have 

 been small particles of sand or flint in the powder, he 

 experimented by adding to them; but neither friction 

 nor percussion, as he tried them, would ignite the 

 powder. He asked the schoolmaster, and the doctor, 

 the learned men of the district, but got no solution. 

 He said he could not rest; he lay awake at nights 

 thinking, when it suddenly occurred to him that his 

 gunbarrel was full of air at a certain temperature, 

 and he asked himself the question, "What becomes of 

 the heat in the air if suddenly compressed? would it not 

 be sufficient to ignite the powder?" Acting on this 

 thought he got an old pistol-barrel, polished it well 

 in the bore, plugged the touchhole, fitted a perfectly 

 air-tight piston, on the bottom of which he had a 

 small projecting pin, on which he wound cotton 

 lampwick saturated with powder softened by alcohol, 

 and by sudden concussion ignited it. He was 

 greatly elated, thinking he had made a new discovery. 



Soon after this he went with his father to Carlisle, 

 and there he saw a glass air-compressing pump, 



with a little cup in the piston for holding tinder to 

 lie ignited by the percussion of the air; and when no 

 tinder was in it the flash of light could be seen. He 

 also found in the hands of boys at the college little 

 brass percussion pumps for igniting tinder. 



This only increased his longing to get out into the 

 world and learn what was doing and what had been 

 done. His father, finding him so set in this, took him 

 to Philadelphia.* 4 All he asked was a chance to 

 learn, and he would take care of himself. 



Lukens' little shop was just the place. Although 

 Lukens wanted help, he was averse to taking any one 

 for a fixed time under instruction. He said to my 

 father that it was easy enough to get any number, but 

 not so easy to get rid of them if they did not suit him; 

 for no matter how ill they filled the place, he could 

 not turn them adrift. When the circumstance of the 

 discharge of the rifle was related to him he decided to 

 take Saxton, for he said that a boy who could work 

 back from effect to cause was the making of a man. 

 In this case the boy had stretched up to nearly, if 

 not quite, six feet tall. [22] 



84 According to Henry, Saxton, in company with two other 

 boys, floated down the Juniata and Susquehanna to Harrisburg, 

 where they sold their boat and continued to Philadelphia on 

 foot. 



60 



