386 TRANSACTIONS OF THE AJUERICAN INSTITUTE. 



I have added to my cannon a little device suggested to me by 

 an article in the Scientific .American six or eight weeks ago> 

 which stated that sharp shooters at 800 yards distance could 

 shoot down, within sixty seconds, every horse, and disable every 

 man of a battery. I have added, therefore, this protecting shield 

 or screen, which ordinarily lies between the trunnions and the 

 wheels, but when to be used by flying artillery, may be very 

 quickl}'' unfolded, and will be proof against the balls of Minie 

 rifles, protecting the gunners and horses. Of course, I should not 

 expect so liglit a structure to be proof against cannon balls; but 

 its elasticity and strength will be sufficient to protect those who 

 are behind it from sharp shooters. This little model is made 

 upon a scale from the six-pounders used in the army. Seven and a 

 half times its size corresponds to the size of the six-pounder. It 

 is evident, tlierefore, that there will be the same amount of room 

 for the folded shield on the six-pounder as on the model. 



The performance of this little piece has been witnessed by 

 Gen'l Wm. Hall and his staff, and also by Colonel Rowan, C. B., 

 of H. B. M.'s artillery, now in this city, who was in the Crimean 

 campaign, and is a thorough scientific man. 



I omitted to mention that the principle of this cannon removes 

 the objections to revolving cannon which have hitherto proved 

 insurmountable. It has been found that revolving cannon could 

 not be fired oftener than single barrels, on account of the heat, 

 and the free ventilation will prevent that. It will be observed, 

 too, that the weight of a revolving gun will be very materially 

 diminished by opening the barrel in the manner I have described. 



Mr. Stetson. — Mr. De Brame has explained this so fully and 

 clearly as to leave very little for us to say, further than to certify 

 to the facts in the experiments we witnessed. We saw the piece 

 charged and fired repeatedly. The charges were prepared under 

 the immediate supervision of Mr. Dibben, so that there could be 

 no deception about it. We found that the penetration without 

 this cap was greater, the difference being distinctly recognized 

 by counting the sheets of paper through which the balls passed. 

 It would require further trials upon a larger scale to determine 

 whether the theory is true, but all the experiments with this 

 model were favorable to the invention. 



The sheet iron curtain is a separate invention, and seems to be 

 entitled to be regarded with favor. It is no new thing to use 

 readily removable shutters in fortifications ; and I think they 



