the run was finished. As may be imagined, all this required a long period of anxious thought and a series of experiments, but eventually Mr Whitehead brought to the notice of the world what had not often been seen before, an entirely new invention perfect in every detail. Its efficiency was demonstrated on trial, and the weapon adopted by nearly every maritime state. What limited its usefulness was the comparatively low speed, which at first was about 8 knots. Hence, if discharged at a vessel half a mile off, it took a considerable time to traverse the distance, so that any little inaccuracy in its course, currents, or alteration of direction in the vessel aimed at would result in a miss. A great advance was therefore made when the speed was increased to 18 knots by the use of Mr Brotherhood's well-known three-cylinder air engine, a model of compactness, simplicity, and efficiency. When gun cotton was used a less amount of explosive was required for the same result with gunpowder, and hence a smaller torpedo could be employed. The improved weapon was 14 ft. long, with a diameter in its largest part of 14 in. Complete it weighed about 500 lbs. Plant for the manufacture of these torpedoes having been established at Woolwich, a healthy competition arose between our officers and Mr Whitehead's staff, for having started a factory at Fiume in Austria he was now supplying other Governments with torpedoes. Succeeding improvements brought the speed up to 27 knots an hour for a distance of 600 yards. This was the range selected as that at which the torpedo should be discharged at a
