Page:The Development of Navies During the Last Half-Century.djvu/332

 gyroscope, in keeping the torpedo on a straight course, so that any deviation and consequent inclination of the torpedo is at once corrected by the gyroscopic pull in the opposite direction. Hence the torpedo travels in the line of projection, and is not deflected by the passing water when launched from the deck of a vessel proceeding at any rate of speed. This is the most valuable quality of the torpedo, as it obviates the necessity of calculating deflection due to different speeds of ship, which with the Whitehead torpedo have to be carefully verified and collated. On the other hand, the latter has a considerably higher speed, which, moreover, is uniform throughout the run, the engines being governed to work at a set pressure from first to last. But in the Howell the flywheel, having when spun up the enormous velocity of 9000 revolutions a minute, has throughout the run a continually decreasing velocity, diminishing the speed of the torpedo until it stops altogether. It is easy to understand that a subaqueous missile which reaches a vessel with sluggish movement has no chance of penetrating a net, and is more liable to be diverted from the object. If this defect can be remedied, and the speed increased, there is a simplicity about the Howell torpedo which to me is very attractive. The absence of an air chamber much reduces the length, which is important on board ship, and in proportion to the amount of explosive the total weight of the torpedo is considerably less than the Whitehead. The present efficiency of the latter has been the work of some years, and I understand it is at last to be adopted in America;