478 MR. E. J. REED ON THE RELATION OE FORM AND DIMENSIONS TO 
The questions I now wish to consider are these : presuming it to be necessary to build 
another ship, which shall steam at the same speed, carry the same proportionate supply 
of coal to engine-power and proportionate quantities of stores, but shall have her armour 
and backing of double the weight of the armour and backing of the 4 Bellerophon’ and 
‘ Minotaur,’ then (1) what will be the size, engine-power, and cost of the new ship if built 
of the 4 Minotaur ’ type, and having the same mean draught and depth of armour 1 and 
(2) what will be her size, engine-power, and cost if built of the 4 Bellerophon’ type, and 
having her mean draught and depth of armour \ — this condition implying, of course, that 
the same constants of performance as before will be realized in each case. Looking 
to the great disproportion of size between the two types of ship, it is obvious that the 
smaller one will require a much less weight of stores, crew, &c. than the larger vessel ; 
we will therefore take the weight to be carried by the latter, in addition to the weight of 
engines, boilers, and coals, as 1000 tons, and that to be carried by the former 700 tons. 
The engines in each case are to weigh 1 ton per nominal H.P., and to work up to seven 
times that power. The coal is to be equal to the weight of the engines in each case. 
Taking first the case of the new ship of the 4 Minotaur ’ type, and calling the half 
breadth of her mean level section 5 , we shall have (since for similar curves the lengths 
are proportional to a dimension, and the areas to the square of a dimension) 
Length along the side of the 
mean level section J 2t5 ' 8 
13333 
Area of the mean level section =— =rr 5 2 =18-5 6 5 2 . 
26 - 8] 2 
Length of armoured side =^-; ^ = 15-675. 
Length between perpendiculars b =14-95. 
mersed mid. sec. i 26-8 
Area of armoured sides =2x15-675x22=689-55. 
Area of surface for hull =2{14-75x 24^-f 15-675X 16|} =1241-85. 
Weight of armour and backing = 689-55 X '22 tons= 151-695 tons. 
Weight of hull 
=1241-85 x T52 tons=188-755 . . . (1) 
and 
Nominal horse-power =y I.H.P. = 31*535, 
Weight of engines and coals=2 nom. H.P. =63-065 tons. 
