due to the increase of radius through quick steam raising and the consequent saving in ability to lie at a base consuming no coal.
In the war with Russia it was found that Japanese ships with cylindrical boilers consumed five times the coal burned by those with water-tube generators, owing to the fact that, having to be ready for sea at two hours' notice, they had to keep fires going while the Belleville boilered ships were able to let fires out.
At some time in the future steam is destined to be replaced by some other motive power, possibly some form of the internal combustion engine, but this can only come about by a further increase of radius or some great advance in speed which shall be equivalent to an extension of radius. Finally electricity is looked upon as the eventual motive power, and this will no doubt endure for a considerable while.
History, however, shows us that motive power when it was the oar, was profoundly affected and finally displaced by the necessity of adopting artillery. The relative merits of oar and sail were comparatively nicely balanced when artillery demanded the space occupied by the oars. Artillery also, from its ability to strike over a relatively great distance where previous weapons had had a very small radius of action made itself more important than motive power. Masts and sails, oars and rowers were alike at its mercy tactically, and the need of motive power declined. At Lepanto, for instance, the six great galleons which won the day
