90 ANNUAL OF SCIENTIFIC DISCOVERY. 



the fire is complete, the two pieces of metal fitting each other in a 

 similar way to that of the keystone of an arch fitting the stones on 

 each side. A small round bush enters the breech end of the barrel, 

 and surrounds the cartridge and breech-pin at their junction so as 

 effectually to prevent the leakage of smoke or fire when the piece is 

 discharged. 



The cartridge deserves special attention. It is composed of the 

 usual materials with a conical ball cemented into it. The rear end, 

 however, has a leather button or disc attached to it, of somewhat 

 larger diameter than the bore of the barrel. This is why a lever is 

 employed to force it into the barrel. This leather button is perforated 

 in the center to receive the flash from the cap, as above described. 

 The first fire of the gun will leave this leather button (which is pre- 

 viously greased,) in the large end of the barrel, and the second fire 

 will force the button through the barrel, thoroughly cleaning it for the 

 discharge which immediately succeeds. The result of this is, that the 

 gun is kept constantly clean. However, as the leather button is left 

 in, every time, it would seem to be necessary to expel it, or draw it 

 out by some other means than by firing, when it is intended to lay by 

 the gun, otherwise the effect of the last shot would still remain in the 

 barrel. A ramrod is furnished with each gun for this purpose, or for 

 uncharging, or for loading the gun at the muzzle in the old way. 



The lock is a slight improvement upon the ordinary locks : the 

 lever hangs upon a pin with an elongated hole, which allows it to rise 

 and fall so as to avoid the necessity of another piece of metal between 

 it and the piece which works the tumbler, simplifying that which has 

 always been the most complex portion of fire-arms. 



Gibbs' Patent Revolver. This invention differs essentially from 

 Colt's Revolver, in having no center-pin to the cylinder, which 

 revolves on two raised bearers inside a fixed brass case, covering two- 

 thirds of the cylinder above, and a slide bearing the weight of the 

 cylinder below. This slide is easily withdrawn when it is desirable to 

 take out the cylinder. The slide is so constructed as to continue 

 under the barrel in the shape of a stock, leaving space sufficient 

 between the slide and the barrel to permit of the exit of all the balls 

 at once, should they all go off, without danger to the person, the cover- 

 ing above the cylinder protecting the eyes and face, and the slide 

 below protecting the hand from the effects of such an accident. The 

 inventor declares that he has fired five cartridges and balls at once, 

 without harm. The cylinder is revolved in the most simple manner 

 by a slide similar to a trigger, working in a slat in the under side of the 

 case or breech, formed by the brass slide already described. This 

 trigger is worked by touching it with the left hand, every motion of 

 which acts upon the cylinder within, by means of a catch, of which 

 there are seven round the cylinder. 



Porter's Patent Rifle. One of the most recent and important 

 improvements in fire-arms, is the self-loading rifle, invented by Mr. 

 P. \V. Porter, of Tennessee, which in its construction and use is as 

 sure as it is commendable. The barrel and stock of this gun are not 



