ItECENT EXPERIMENTS ON FOG SIGNALS. 1 



while the 12-lb. howitzer and the 18-pounder were both 

 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-J Ib. of gun-cotton detonated in the focus of a 

 reflector (see annexed figure), and !- 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 ail 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. 



