Description of the Vei aission Gun-Lock. 1 85 



Take oxymuriate of potash ^9 grains, flour of sulphur 17 grains, 

 pulverized charcoal Sf grains. Mix the three ingredients in a 

 wooden mortar, with atea-spoonfull of weak gum water, making 

 it about the consistence of hookbindcrs' paste. Have ready a 

 piece of copper or brass plate, pierced with circular holes of one- 

 eightli of aii inch diameter, lay it on a board, and spread the 

 composition over it, so as to fill up all the holes. Allow twenty 

 minutes for the paste to harden, push the pellets out with a 

 wooden punch that fits the holes, and spread them to dry more 

 completely, after which they may be fixed with any adhesive com- 

 position upon small circular pieces of thin paper for use. 



Many testimonials in favour of Mr. C. Hall's invention from 

 persons who had used it for some months, accompanied the ori- 

 ginal communication, but which it is not thought necessary to 

 insert here. They remain, however, in possession of the So- 

 ciety, as also does a model of the lock. 



Explanation of the Figures. — Plate U. 



0, fig. 1, the lock-plate of a common gun, with the hammer 

 and feather spring removed, and the screw holes plugged up ; the 

 pan also being filed off level with the lock-plate and bevelled to 

 drain the rain off". 



b, the hammer placed on the axis of the tumbler in place of 

 the cock. 



c, a plug screwed into the breech where the touch-hole for- 

 merly was ; which plug is perforated through its whole length at 

 right angles to the axis of the barrel. 



d, a small pin or nipple left on the plug, through which a hole 

 is bored at right angles to the axis of the plug. The top of the 

 pin is so placed as to strike directly on the centre of the priming 

 patch in the head of the hammer, when the hammer is released, 

 as shown by the dotted arc, Jf. 



e, a bush made of platina screwed into the end of the plug, 

 and perforated by a capillary tube, in order to moderate the effect 

 of the detonation, and thus prevent the powder from being blown 

 out of the plug before it is ignited. 



Fig. 2 is a front view, the barrel being cut off close to the 

 plug. 



Figs. 3, 4, are a lateral view and section of the plug. 



Fig. 5 is a section of the hammer to show the cavity g, in 

 which the patch is deposited. 



Figs. 6, 7, a plan and elevation of the patch. 



Vol. .'.G.No. 2G1). Sept. 1820. ' A .i XMX. For- 



