WEIGHT AND SUPPORT IN SHIPS. 
453 
of weight. In still water the bending-strain (in proportion to the products of the dis- 
placements and the lengths) is about one half as severe in the ‘ Bellerophon’ as it is in 
the ‘ Minotaur,’ on a wave-crest it is less than tivo-thirds as severe, and in a wave-hollow 
it is proportionately about one and one-fourth as great in the ‘Bellerophon’ type as it 
is in the ‘ Minotaur.’ Another point of contrast is found in the fact that the maximum 
hogging- and sagging-strains are practically about equal in the 6 Bellerophon’ type, 
whereas in the ‘ Minotaur’ the hogging-strain is very nearly double the sagging-strain. 
The longer ship must have, therefore, a very great reserve of strength against sagging if 
she is strong enough to resist hogging ; and this fact prevents the material from being 
so well disposed as it might be if there were not so great a difference between the two 
extremes of strain. This follows from the consideration that an iron-built ship, such as 
the ‘ Minotaur,’ is comparatively strong against sagging, because (if the longitudinal 
strength of the keel and keelson-work is kept up, and the bottom plates are properly 
butt-strapped) there is sure to be a reserve of tensile strength in the bottom, and because 
under compressive strains the wood upper deck becomes very effective ; whereas against 
hogging the upper part of the ship is usually much weaker, both absolutely and as 
compared with the lower part. In the case of an armoured ship like the ‘ Minotaur,’ 
the power to resist sagging is also added to very greatly by the resistance offered to 
compression by the upper strakes of armour, which contribute besides, in a considerable, 
although a much less degree, to her power to resist hogging. 
The preceding comparison, as I have said, is limited to the consideration of the ‘ Mi- 
notaur’ and ‘Bellerophon’ as types ; but there remains to be considered the important 
question of the actual strains experienced by these two vessels when in their extreme 
positions of support among waves. These are as follows : — 
On Wave-crest. 
Minotaur. 
Bellerophon. 
Excess of weight forward 
Excess of weight aft 
Excess of buoyancy amidships . . . 
Maximum shearing-strain 
Maximum bending-moment 
1,275 tons. 
1,365 „ 
2,640 „ 
1,365 „ 
140,300 foot-tons. 
445 tons. 
555 „ 
1,000 „ 
555 „ 
43,600 foot-tons. 
3 R 
MDCCCLXXI. 
