THE LOCK. 237 



ifficiently so to make it dangerous experience alone can de- 

 termine. It is certainly an improvement upon Mr. Greener's 

 original plan, and as such is introduced here : 



fig. 2 7. 



THE GREENER-HORTON BREECH. (FULL SIZE.) 



On comparing this with the ordinary breech (fig. 24, p. 

 234) it will at once be seen that in Horton's plan the nipple 

 is brought nearer to the charge, and may possibly be more 

 liable to be blown out, but with proper care in tapping I 

 have no doubt such an accident would never occur. That 

 the firing is sharper I fully believe from theoretical calcula- 

 tion, but whether in practice the difference would be dis- 

 covered I do riot pretend to say. One advantage is possessed 

 by Horton's breech viz., that a pin or pricker may be passed 

 straight down into the chamber, and thereby any accumula- 

 tion may with certainty be disposed of; whereas, in the 

 cross-hole it meets with an angle, and cannot get any further. 

 In the gun-trial of 1858, a gun made on this plan was shot 

 by Mr. Horton and performed well, though from his ner- 

 vousness the shot from the first barrel almost entirely missed 

 the target. 



THE LOCK. 



The lock of the percussion gun is a very simple and effi- 

 cient piece of mechanism, having for its object to explode 

 the cap on the nipple by means of a sharp blow, which must 

 be so arranged as to finish with its greatest amount of 

 strengths so as to prevent the hammer from being blown up 



