72 
Account of a New Method of projecting Shot. 
IJ. — Account of a New Method of projecting Shot. From the Pro- 
ceedings at the Royal Institution. 
[Journal of Science and the Arts, vol. III. N. S.] 
Mr. Brockedon gave some account of a new method of projecting shot, which 
had been discovered by Mr* Sieviere the sculptor. Mr. Sieviere had furnished 
Mr. Brockedon with a report of his earliest experiments, and to some of a later date 
Mr. Brockedon was an eye-witness. The discovery was accidentally made many years 
since by Mr. Sieviere, who was one evening amusing himself with a pewter syringe, 
which he had converted into a cannon, having closed the discharging end of the 
syringe, and made a touch-hole. Into this cannon he put some pinches of gun- 
powder, and discharged the piston from it, which fell harmless at a short distance; 
happening to invert the order of tiring by holding the piston, the syringe wa . dis- 
charged with so much violence, as to pass through the ceiling and floor into the 
chamber above that in which he sat. He was struck with the prodigious difference 
of effect produced, and immediately had a shot cast, which in form was like a mor- 
tar : this he fired from a solid mandrel, or bar swung upon trunnions, and capable 
of elevation and adjustment. His experiment succeeded so entirely, that he was 
induced to make a shot with radiant bars, which, though they added little to its 
weight, added much to its power of destruction to rigging, Ac. The weight of this 
shot, which was of cast iron, was 15 pounds ; this was discharged through a bank 
of clay 6 feet thick, and fell 20 yards beyond it- When fired again, it hit point 
blank at distance of 175 yards, and was buried above 3 feet in the bank ; the cham- 
ber of this shot, with which a touch. hole coinimmicn’ed, was precisely like that of 
a mortar, and when it was placed for firing upon the mandrel, the shoulder of the 
chamber at the Dottom of the calibre rested upon the end of the mandrel. The 
chamber contained a charge of 1£ ounces of gunpowder. An experiment was made 
with a shot which weighed 25 pounds, but a charge of 2^- ounces of gunpowder was 
so great as to burst it, and to throw a fragment of 5£ pounds' weight to a distance of 
more than a quarter of a mile. Subsequent experiments with shot of wrought and 
cast iron of different forms, confirmed the fact, that shots discharged with the ma- 
gazine « i:hin them were projected with a force greatly exceeding that which the 
same quantity of gunpowder applied in the usual way would effect. 
Mr. Brockedon attempted to account for this greater force bv supposing, that 
the power usually wasted in the recoil of the gun, was added to the force by which 
the shot and mandrel were separated. Hestated, thatno recoil in common gunnery 
took place, until the shot had left the cannon ; and offered the following proofs of 
this fact. It is a common practice to fire a cannon suspended from triangles : the 
mark against which it is directed being hit, if any recoil had taken place before the 
ball Jett the cannon, the ball must have struck some other point tangential to the 
cirde which its point of suspension would describe. Mr. Brockedon mentioned 
that M r. Perkins, m the course of some experiments upon recoil, had fastened a 
loaded rifle barrel to the edge of a horizontal wheel, which moved freely upon a ver- 
tical axis ; the rifle was directed, and hit the mark, though the recoil whirled the 
rifle and wheel round with great velocity. Mr. Brockedon illustrated this further 
by supposing a boat on st.ll water, and imagining a plank placed from stem to 
stern, and a man on it pushing with a pole a bundle of hay from him along the 
plank, the separation of the hay from the man could not affect the situation of the 
boat on the water, whilst the hay was on hoard ; but if the hay were thrust over, 
fromT^hf ff ne mde P end ent of the boat, the man and boat would separate 
nom the hay with forces proportioned to their densities. 
no &r 1 ^ to contain the ? lloducte of the combustion of gunpowder, has 
bf Xrs ft i onnf by but vaguely stated by some at 500, 
oy others at 1000 times the volume of the powder ; taking the lowest statement 
five posin £ a cartridge to be six inches long, and the length of the eun to be 
X tie ban m r ab0Ut the by g comtXfope^ 
the vis ine t L'o/thr^r, 1111 '^ ***** "'f *f d , lip ° n a recoi1 ’ «Mch, overcoming 
tons foSfpoute" We,ghs ! ,etween three and fou? 
plane 18 inches or two feet The * Jh serv ' ct N “gainst an inclined 
place, and the products of’conTl f i leaves . thu gun the recoil takes 
condensed and heated sta e , ^ i - rema ' n w,tllin thc ™ « highly 
state, are opposed in their escape by the vis inert!® of the 
