158 PNEUMATICS. 



violence by means of condensed air. Plate 7» 

 fig. 8. represents an iron condenser, for condensing 

 air into the hollow ball b : at the end a of the con- 

 denser there is a male screw, on which the ball is 

 screwed. In the inside of this ball is a valve, to 

 hinder the air, after it is injected, from making its 

 escape, until it be forced open by a pin, against 

 which the hammer of the lock strikes ; which then 

 lets out as much air as will drive a ball with con- 

 siderable force to a great distance. 



When you condense the air in the ball, place 

 your feet on the iron cross k h, to which the piston- 

 rod d is fixed ; then lift up the barrel e a, by the 

 handles i i, until the end of the piston is brought 

 between e and c ; the barrel a c will then be filled 

 with air through the hole e. Then thrust down 

 the barrel a c by the handles i i, until the piston e 

 join with the neck of the iron ball at a. The air 

 being thus condensed between e and a, will force 

 open the valve in the ball ; and when the handles 

 i i are lifted up again, the valve will close, and 

 keep in the air : so, by rapidly continuing the 

 stroke up and down, the ball will be filled ; after 

 which, unscrew the ball off the condenser, and 

 screw it upon another male screw, which is con- 

 nected with the barrel, and goes through the stock 

 of the gun, as represented Fig. J. Twelve dwts. 

 of air have been injected into a ball 3.J5 inches 

 diameter, which has discharged 15 bullets- with 

 considerable force. 



There are many varieties of air-guns : some 

 have a small barrel contained within a large one ; 

 and the space between the two barrels serves for 

 the reception of condensed air. In this sort, a 

 valve is fixed at a (Fig. 7«)> w ^ tn a condenser 

 fixed to the barrel, and continued through the butt- 



