SHORT NOTES ON PROFESSIONAL SUBJECTS. 
53 
For most elongated service forms, the value of b will be practically constant and 
will equal 0-00181. 
For spherical projectiles it has been found advisable and convenient to double 
this, so that the value of b will be 0-00862. 
or b = 0-00181 for elongated projectiles, 
b = 0*00862 for spherical projectiles. 
With regard to z for elongated projectiles, 
z — 0'025 from the highest velocity to 1200 feet, 
0 — 0-020 after 1200 feet. 
With spherical projectiles this value of z is approximately as follows,— 
1900 to 1700, 0 = 0-0*24. 
V= 1700 to 1600, 0 = 0-022. 
V= 1600 to 1400, 0 = 0-020. 
Vz= 1400 to 1000, 5= 0-018. 
47. On the Defects of Side-Arms For Muzzle-Loading Guns. 
Lieut. Greenfield, E.A., has forwarded the following remarks on this subject 
The Sponge * 
Till within the last ten or twelve months it was believed that the pfeseiit service 
sponge was a tolerably efficient instrument for cleaning out guns after firing; but 
the evidence collected by a Board of Staff Officers (of which Col. L. Gardiner, 
Asst.-Adjt.-Gen., E.A., was President) 27/7/67, relative to three accidents that 
occurred in July last at Gosport, Portsmouth, and Dover, and which proceedings 
were laid before the O.S. Committee, together with the result of experiments con¬ 
ducted under their orders (Eeport No. 4851, 31/12/67), have proved the following- 
facts, viz—that in firing blank ammunition a portion or portions of the cartridge 
remain in the bore after each round; and that the action of sponging out, only 
presses them home to the breech and there leaves them. 
In consequence of this discovery, two changes have been approved* first in the 
service of the gun, the second in the material of the cartridge case. With regard 
to the latter, the Committee have been led by experiment to adopt a substance 
from the French—Amiantine cloth, a fabric made of refuse silk, which as its 
name denotes, does not smoulder or burn, but which yet remains in the gun un- 
destroved, in tolerably large quantities, sufficient to cause two miss-fires in fifty 
rounds. The same is well known to occur with serge cartridge, and its liability to 
smoulder depends upon its preparation. 
