pears to be
washed away smoothly by the gases, and not pitted and eaten into as with
black powder. The erosion also extends over a shorter length of surface,
and in small arms it is said to be no greater than in the case of black
powder. Sir A. Noble says in this connection: "It is almost unnecessary to
explain that freedom from rapid erosion is of very high importance in view
of the rapid deterioration of the bores of large guns when fired with
charges developing very high energies. As might perhaps be anticipated
from the higher heat of ballistite, its erosive power is slightly greater
than that of cordite, while the erosive power of cordite is again slightly
greater than that of brown prismatic. Amide powder, on the other hand,
possesses the peculiarity of eroding very much less than any other powder
with which I have experimented, its erosive power being only one-fourth of
that of the other powders enumerated."

TABLE GIVING SOME OF SIR. A. NOBLE'S EXPERIMENTS.
________________________________________________________________________
| |
| VELOCITIES OBTAINED. |
|________________________________________________________________________|
| | | | | |
| | In a 40 | In a 50 | In a 75 | In a 100 |
| | Cal. Gun.| Cal. Gun.| Cal. Gun.| Cal. Gun.|
|____________________________|__________|__________|__________|__________|
| | | | | |
| |Foot Secs.|Foot Secs.|Foot Sees.|Foot Secs.|
| | | | | |
|With cordite 0.4 in. diam. | 2,794 | 2,940 | 3,166 | 3,286 |
| " " 0.3 " | 2,469 | 2,619 | 2,811 | 2,905 |
| " ballistite 0.3 in. cubes| 2,416 | 2,537 | 2,713 | 2,806 |
| " French B.N. for | | | | |
| 6-inch guns | 2,249 | 2,360 | 2,536 | 2,616 |
| " prismatic amide | 2,218 | 2,342 | 2,511 | 2,574 |
| | | | | |
|____________________________|__________|__________|__________|__________|
|