224 
MINUTES OF PROCEEDINGS OF 
ACCOUNT OF EXPERIMENT CARRIED ON AT SHOEBURYNESS, ON THE 29th 
DECEMBER, 1862, AGAINST A SHIELD CONSTRUCTED ON THE PRINCIPLE 
PROPOSED BY CAPTAIN INGLIS, R.E., REPRESENTING AN IRON EMBRA¬ 
SURE, FOR EITHER CASEMATED OR OPEN COAST BATTERIES. 
[CONTRIBUTED BY CAPTAIN E. J. BRUCE, R.A.] 
The target measured 11' in length by 8'2" in height, and contained an 
embrasure 3' 6" high x 2' 4" wide. It was composed of vertical planks 
of hammered iron of various dimensions, namely, V 11" x 8", V 11" x 7", 
1' 7J" x 8", V 7J" x 7", and V 7?" by 6", backed by horizontal planks of 
rolled iron, 14" wide by 5" thick, and secured by 3-in. screw bolts and some 
3-in. rivets. 
One half of the target represented half of a shield 12' wide, the other 
half one 10' wide. 
It was secured to a frame consisting of four vertical pieces 1' 2" x 4", and 
two horizontal pieces P 2" x 5", and the whole was supported at either end 
by a boiler-plate strut, having a base of 3', and made up of a web of 1-in. 
plate and angle irons 8" x 5" x 1" and 5" x 5" x 1". These struts were 
riveted to sill pieces 14" x 4", and these again secured to a cross beam 18' 
long, 11" wide, and 3" deep, and placed 6' in rear of the shield. The cross 
beam was heavily weighted, and secured at each end by a mass of masonry, 
and formed the sole means of holding the shield in its place. The boiler¬ 
plate strut, at the end representing the 10' shield, was made to splay out¬ 
wards at an angle of 15° from the perpendicular,* as this would be necessary 
in actual practice to admit of the required traverse of the gun (7 0°). The 
other strut stood perpendicular to the shield. 
Between the surfaces of the front and rear, layers of Plank's sheet lead were 
introduced, weighing 6 lbs. per foot superficial; and under the nuts of the 
screw bolts several descriptions of elastic washers were used. Some of these 
washers were of the nature of buffers, composed of 3" of india-rubber inside 
a strong wrought-iron cylinder ; others w r ere of coils of wire rope similarly 
confined; and in other cases, several lead washers, and washers of iron and 
brass were used. 
The shield was made at Messrs Mare's Works, at Millwall. 
The planks were numbered from 1 to 5, commencing on the left. 
The following guns were used in the experiment:— 
One 120-pr. Whitworth rifled gun. | One 110-pr. Armstrong rifled gun. 
One 68-pr. smooth-bore gun. 
The following shot struck the shield:— 
From 120-pr. Whitworth gun f ° ne ^ 0 “ nd T J d t d solid cast - ir0 " .t 0 ,. 1 wei ?\ t ; 
r C One flat-ended homogeneous solid shot, 130 lbs. weight. 
From 110-pr. Armstrong gun j ®?' id cast-iron shot 110lbs. each. 
r ° ° l Two solid cast-iron shot, 68 lbs. each. 
From 68-pr. gun . Five solid cast-iron shot, 67 lbs. each. 
Range 200 yds. 
This arrangement will not be required, as all shields are to be 12' wide. 
