624 
EFFECT OF SHELL ON MUD WALLS. 
A. 
From Lieut.-Col. W. Carey, R.A., to the Bde.-Major ft.A., Southern 
Afghanistan. 
Kandahab, 
15th April, 1881. 
Sir—In forwarding the accompanying reports of experimental prac¬ 
tice carried on by batteries as per margin, with my statement 
■^2 showing a comparison of ammunition and power expended in 
14/9 breaching operations against the walls of Old Kandahar, on 
the 5th, 6th, and 8th inst., I have further to state that the 
face of the wall was 30 ft. high, while in the interior of the work it 
only measured 20 ft. 
The wall was originally faced with sun-dried bricks inside and out, 
and all gateways lined with the same material, otherwise the whole 
depth consists of made clay iu layers of 12 to 18 inches. 
The firing carried on by 14/9 was commenced by cutting a hori¬ 
zontal line a little below \ the height of the front or face of the wall, 
that is 15 + 2, about 17 ft. below the top, or only 3 ft. above the 
interior level. On close inspection I found such was the case, unless 
indeed it was still lower, and at that level the wall was 28 ft. thick. 
The O.C. 14/9 gives the breach as 16 ft. wide, my measurement makes 
it only 14 ft., so that the actual lines cut were 10 ft. longer than 
necessary. Under these circumstances it is not surprising that the 
line of fire had to be continually and gradually raised, forced upwards 
by the accumulating debris, until the guns pierced and breached the 
wall 8 ft. below the top. 
The “F” batteries appear to have laid their guns about 10 ft. 
below the top, so that time was gained to shake and nearly penetrate 
the wall before the falling earth caused the line of fire to be raised, 
and the upper portion 5 or 6 ft. of wall was then easily blown away. 
From inspection after the breaches were made there would have been 
no difficulty in cutting down 4 ft. or more of the shattered wall. In 
this way the field batteries with lighter guns appear to have effected 
an equal amount of work as the 40-prs., with a saving of one-third the 
weight of projectiles, bursting shell charges, and power in foot tons. 
With regard to the description of fuzes used with common shell, I 
am of opinion that those fired with metal plugs and time fuzes bored 
to act at comparatively the same time are the most effective, as the 
whole power of the shell is thus thrown into the work, plugged shell 
breaking up and exploding apparently at the end of penetration. At 
times the effect was most marked by larger masses of earth coming 
away, leaving deep craters. 
With regard to shell bursting, as far as I could judge by eye and 
ear, it was in the following order fuzed with—- 
1st. Percussion fuze. 
2nd. Time fuze, 2/10, 3/10, 4/10, 5/10 th . 
3rd. Shell with metal plugs, or 7/10 th time fuze. 
Unbored fuzes did not appear to delay the action more than the 
