WEIGHT OP MATERIAL IN THE CONSTRUCTION OF IRON-CLAD SHIPS. 477 
Supposing the mean sections at these depths to be parallel to the construction water- 
lines, we find from the drawings that their dimensions are — 
‘ Minotaur.’ ‘ Bellerophon.’ 
Half breadth extreme 26-8 ft. 26 ft. 
Length measured along the side . . . 394 ft. 305-5 ft. 
We also find from the drawings that the mean lengths of the horizontal sections of 
the armoured sides are — 
‘ Minotaur,’ 420 ft. 4 Bellerophon,’ 320 ft. 
Let us now suppose that the weight of the armour and backing is uniformly distributed 
in each case oyer vertical prismatic sides of the dimensions of the armoured sides, and 
that the weight of the hull is similarly distributed over vertical prismatic sides of the 
dimensions below water of the mean horizontal section, and above water of the armoured 
side, observing that the total depth of the armour and backing on the ‘Minotaur’ is 
22 feet, and on the 4 Bellerophon’ 20-3 feet, and that the ‘Minotaur’s’ armour descends 
5f feet below water, and the ‘ Bellerophon’s’ 6 feet. 
Then we shall have 
Weight per sq. ft. of armour and backing . 
Minotaur. 
2111 
Tons. 
='1142; ? 
Bellerophon.’ Tons. 
1383 
2 x 420 x 22 " ’ 2 x 320 x 20*3“ 
‘ Minotaur.’ Tons. ‘ Bellerophon.’ Tons. 
5092 3477 
Weight of hull 2 x 394 X 24-U- + 2 x 420 x 16| = ' 153 ’ 2 x 305-5 x 22i + 2 x 320 x 14-3 “ 
In these two classes of ships, therefore, we have very similar conditions as respects 
weight per sq. ft. both of hull and of defensive material carried (armour and backing). 
The ‘Minotaur’ has slightly the heavier weight per sq. ft. for both, but as the ‘ Belle- 
rophon’ has a large reserve of strength compared with ‘ Minotaur,’ we may without error 
take the mean weights per sq. ft. both of hull and of armour and backing to be the same. 
We shall thus have in round numbers for both ships — 
Weight per sq. ft. of hull =-152 ton. 
„ „ armour and backing =-11 „ 
Here, then, we have two types of ship (the ‘ Minotaur ’ 400 feet long between perpen- 
diculars and 59 feet 3^ inches broad, and the ‘ Bellerophon ’ 300 feet long and 56 feet 
broad), both steaming on the measured mile at fourteen knots, and both having equal 
weights per sq. ft. of hull and of defensive armour and backing ; and it has been ascer- 
tained that on their measured mile trials, which were conducted in precisely the same 
way, and with both ships fully rigged, they have given the following mean constants of 
performance calculated from the formula 
r . mid. sec. x speed 3 
t= ULR > Y1Z - 
‘ Minotaur.’ 
Mean constant. . . . 572-9 
* Bellerophon.’ 
516-5 
