PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 567 



a broadside, the expediency of sucli a change is questionable. It 

 wouhl be easy to construct a smaller vessel on the same plan, 

 with less proportionate speed, if the projector's present plan be 

 deemed too large ; but the proposed vessel, although of greater 

 power, is only of about the same size as those now building by the 

 English government ; and' if the United States build a vessel, it 

 should be at least able to cope upon the open sea, as well as in 

 the harbor, with any built by any foreign government. 



Mr. Dibben. — They are far more industrious in the investiga- 

 tion of this subject in England than we are in this country. 

 Within a few years a commission of competent engineers has been 

 appointed by government, to examine all inventions designed to 

 aid the public service, and whenever anything is presented which 

 promises to be valuable, the inventor receives facilities for test- 

 ing his plans. Sometimes he receives a salary while he is making 

 his experiments, and in other cases he is allowed the use of the 

 public dock yards. Sir William Armstrong was thus aided in 

 the beginning of his career. 



Mr. Stevens. — Some years ago I made some experiments in 

 firing bullets throug:h plates of different materials. I found that 

 a bullet moving with a velocity of 1,000 feet per second, would 

 cut out a hole in a pane of glass without breaking the glass ; but 

 to cut out a smooth hole in a steel shovel blade, required a velo- 

 city of 3,000 feet per second. 



Mr. Dibben, — I think there must have been some defect in the 

 pendulum with which the velocity was measured, as 1,800 feet 

 per second is the highest velocity ever imparted to a shot. 



Mr. Howell. — Did you try firing candles through a board ? 



Mr. Stevens. — Yes, and they came out in good merchantable 

 condition. 



Mr. Babcock. — I have tried firing candles through a board, 

 and I have found the wicks, but I never could find the candles. 

 Now I am up, I will remark that I learn from Mr. Parrott that 

 he has been making some experiments with wrought iron shot, 

 and he finds that they have no more power of penetration than 

 those made of cast iron. They flatten against the plate. 



Captain W. A. Bartlett.— I saw at Washington, last week, 

 a gun of novel construction, which has proved very eifective 

 indeed, in some of our skirmishes. It is a light rifle, mounted on 

 wheels, throwing a 1-inch bullet, and can be fired 200 times in a 

 minute. Several of the Governors of States have ordered it to 



