368 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



like water tlirough a hose pipe, with that velocity ; for merely 

 to overcome the iDcrtioii of the balls, a horse-power will only 

 tlwow l|-ounce balls at the rate of one per second ; and we must 

 have several horse-powers to overcome the friction. If the 

 machine is small and convenient, the number of bullets thrown 

 must be necessarily very small. 



As to the difficulty of directing the motion, he would not 

 venture to say what could or could not be done. He could not 

 say that human ingenuity might not discover some means of 

 overcoming that difficulty. 



Mr. Stuart remarked that some years since he had had occasion 

 to investigate a centrifugal theory, based upon the principles 

 that double the power produces double the velocity, and thus 

 produces four limes the radial force. 



Mr. Nash said that a steam gun could not be effective unless 

 sheltered, for the moment a cannon ball touches it, there is an 

 end to it. He described the execution which could be done with 

 cannon, or even with rifles, by having a telescopic sight. He 

 had seen it applied to a rifle forty years ago, and it was found 

 in practice to be exceedingly good. 



Mr. C. W. Smith. — The theory that action and reaction 

 are equal, would seem to indicate that if the ball weighs one- 

 one hundredth part as much as the cannon, the recoil should give 

 the cannon one-one hundredth the velocity of the ball. But 

 friction, and the fact that the power is not applied instantane- 

 ously, prevents this amount of recoil from ever practically taking 

 place. A steel gun might be made very light, to have sufficient 

 strength ; but the recoil would be very much increased. He 

 explained the advantages of the Hotchkiss projectile in reducing 

 the amount of recoil, the first shook being expended in the 

 expansive action upon the lead, and the charge of powder being 

 considerably diminished. 



J^ew subject. — On motion of Mr. Seely, the subject of " Ice, 

 and methods of refrigeration" was selected for discussion at the 

 next meeting. 



Adjourned. 



