3 
and Engineers at Charlottenburg 1 with the results displayed in the following 
table :— 
Length of the ogive. in calibres 
Diameter of the flat head. n « 
Ogive. 
Short. 
Medium. 
Long. 
•6662 
•1986 
1-0153 
•0924 
1-3029 
•0891 
^ f wj-i n a j-i C An arc of minimum resistance 2 
■S With flat head, the sur- \ . , • r 
n n, , i . ’ , . A straight line . 
o . face of the ogive being < * ? v 
m grated b y f . "i ~ "i I 
JjJ 
« 'gf ’ pointed, the surface of f A straight line . 
J ^ the ogive being gener- -j A parabolic arc . 
.2 -2 ated by .(.An arc of a circle. 
xn J 
<£> 
^ (cylindrical (maximum) . 
27-84 
29-50 
34-40 
37*59 
36- 03 
37- 93 
39-47 
15-71 
17-37 
21-24 
21- 70 
24-57 
22- 26 
23-49 
10- 52 
11- 92 
14- 87 
15- 26 
12- 84 
15-27 
15-72 
100 
Captain Modi takes this table as a theoretical confirmation of the excellence of 
the profile experimentally fixed for the French projectiles. The obus a mitraille 
of 3*54 inches has an ogive 4*33 inches long prolonged by l 1 69 inch of fuze, 
total, 6’02 inches, or 1*7 calibres, and the front of the fuze forms a flat head 
with a diameter of ‘984 inch, or ‘278 calibre. German projectiles of this calibre 
have an ogive only 2*36 inches long of irregular form. The French Navy pro¬ 
jectiles, which formerly had an ogival angle of 45°, have lengthened their ogives 
and brought the angle down to 30°, Captain M.och says, with good results. 
General Wille’s shrapnel is to consist of a thin steel case with a central tube 
and the charge at the base, the case being strengthened by longitudinal ribs. 
The interstices between the bullets to be filled with sulphur, or any other analogous 
product, unless experience should hereafter show the possibility of replacing this 
useless dead weight by the bursting charge. The weight of the bullets to be 
42 per cent, of the weight of the projectile. (The proportion in the British 
service is 45°/ 0 .) But how is it proposed to give to a shrapnel of 2'756-inch 
calibre a weight exceeding 14 lbs. P The General’s answer might be anticipated 
by those who remember that he is the author of the pamphlet “ Wolfram- 
Geschosse ” which made some sensation in Germany last year : it is that the 
bullets should be made of tungsten coated with steel. Tungsten is derived from 
wolfram, an ore found in conjunction with tin in Cornwall. Its specific gravity 
is about 17*75, that of gold being 19*3; that of the bullets coated with steel 
would, according to the General, be 16. Now the density of lead is only 11*4, 
and of hardened lead (70 lead, 15 tin, 15 antimony) about 9*5, and the ordinary 
weight of a shrapnel bullet is about 183 grains. The General’s bullets of *39 inch 
and *43 inch diameter would weigh respectively 112 grains and. 155 grains. To 
obtain the latter weight with hardened lead would require a bullet with a 
diameter of *51 inch. The General proposes either 250 bullets of 155 grains or 
340 of 112 grains. He estimates the amount of tungsten required for the supply 
1 Archiv f Ur Artillerie-mid Ingenieur OJJiziere, Vol. 94, January, 1887. 
2 Dr. August gives the equation of the curve of minimum resistance. Captain Moch is unable 
to guarantee the reliability of the Professor’s theoretical table given above, more especially as the 
Professor has not taken into consideration the action of the rarefied air in rear of the base of the 
projectile. Captain Moch speaks with authority on the point, as he was a member of the well- 
known and important Commission de Gavre. The action of the rarefied air in rear has been 
demonstrated on moving trains—it is true with much lower velocities. Captain Moch attaches 
importance chiefly to the lengthening of the ogive. 
