ttECENT EXPERIMENTS Oft FOG SIGNALS. 1 
while the 12-lb. howitzer and the 18-pounder were botfti 
beaten by the gun-cotton. On the 2d of May, on the 
other hand, the gun-cotton is reported as having been 
beaten by all the guns. 
' Meanwhile, the parabolic-muzzle gun, expressly intended 
for fog- signaling, was pushed rapidly forward, and on 
FIG. 8. 
Gun-cotton Slab (1| Ib.) Detonated in the Focus of a Cast-iron 
Reflector. 
March 22 and 23, 1876, its power was tested at Shoebury- 
ness. Pitted against it were a 16-pounder, a 5^-inch how- 
itzer, 1 Ib. of gun-cotton detonated in the focus of a 
reflector (see annexed figure), and l Ib- of gun-cotton de- 
tonated in free air. On this occasion nineteen different 
series of experiments were made, when the new experimen- 
tal gun, firing a 3-lb. charge, demonstrated its superiority 
over all guns previously employed to fire the same charge. 
As regards the comparative merits of the gun-cotton fired 
in the open, and the gunpowder fired from the new gun, 
the mean values of their sound were the same. Fired in 
the focus of the reflector, the- gun-cotton clearly dominated 
over all the other sound-producers.* 
* The reflector was fractured by the explosion, but it did good serv- 
ice afterward. 
