846 REPORT—1899. 
the attainment of extraordinarily high speeds, for short periods and in smooth 
water, by vessels of small dimensions. Their qualities and performances, therefore, 
merit examination. 
Mr. Thornycroft may justly be considered the pioneer in this class of work. 
Greatly impressed by the combination of lightness and power embodied in railway 
locomotives, Mr. Thornycroft applied similar principles to the propulsion of small 
boats, and obtained remarkably high speeds. His work became more widely 
known when the results were published of a series of trials, conducted in 1872 by 
Sir Frederick Bramwell on a small vessel named the Miranda. She was only 
45 feet long and weighed 4 tons, yet she exceeded 16 knots on trial. The 
Norwegian torpedo boat built in 1873 was 57 feet long, 7} tons, and of 
15 knots; the first English torpedo boat of 1877 was 81 feet long, 29 tons, and 
attained 18} Imots. 
Mr. Yarrow also undertook the construction of small swift vessels at a very 
early date, and has greatly distinguished himself throughout the development of 
the torpedo flotilla. Messrs. White, of Cowes, previously well known as builders 
of steamboats fur use on board ships, extended their operations to the construction 
of torpedo boats. These three firms for a considerable time practically monopolised 
this special class of work in this country. Abroad they kad able competitors in 
Normand in France, Schichau in Germany, and Herreshoff in the United States. 
Keen competition led to successive improvements and rapid rise in speed. During 
the last six years the demand for a fleet of about 100 destroyers, to be built 
in the shortest possible time, involved the necessity for increasing the sources. 
of supply. At the invitation of the Admiralty, a considerable number of the 
leading shipbuilding and engineering firms have undertaken and successfully 
carried through the construction of destroyers varying from 26 to 33 knots in 
speed, although the work was necessarily of a novel character, involving many 
difficulties. 
As the speeds of torpedo vessels have risen, so have their dimensions increased. 
Within the class the law shown to hold good in larger vessels applies equally. 
In 1877 a first-class torpedo boat was 81 feet long, under 30 tons weight, developed 
400 horse-power, and steamed 18} knots. Ten years later the corresponding class 
of boat was 135 feet long, 125 tons weight, developed 1,500 horse-power, and 
steamed 23 knots. In 1897 it had grown to 1650 feet in length, 140 to 150 tons, 
2,000 horse-power, and 26 knots. 
Destroyers are not yet of seven years’ standing, but they come under the rule. 
The first examples (1893) were 180 feet long, 240 tons, 4,000 horse-power, and 
26 to 27 Imots. .They were followed by 30-knot vessels, 200 to 210 feet long, 280 
to 800 tons, 5,500 to 6,000 horse-power. Vessels now in construction are to 
attain 52 to 33 knots, their lengths being about 230 feet, displacements 360 to 380 
tons, and engine-power 8,000 to 10,000 horse-power. 
Cost has gone up with size and power, and the limit of progress in this direction 
will probably be fixed by financial considerations, rather than by constructive 
difficulties, great as these become as speeds rise. 
It may be interesting to summarise the distinctive features of torpedo-vessel 
design. 
1. The propelling apparatus is excessively light in proportion to the maximum 
power developed. Water-tube boilers are now universally adopted, and on speed 
trials they are ‘forced’ to a considerable extent. High steam pressures are used. 
The engines are run at a high rate of revolution—often at 400 revolutions per 
minute. Great care is taken in every detail to economise weight. Speed trials at 
maximum power only extend over three hours. Onsuch trials in a destroyer each 
ton weight of propelling apparatus produces about 45 indicated horse-power. 
Seme idea of the relative lightness of the destroyer’s machinery and boilers will be 
obtained when it is stated that in a large modern cruiser with water-tube boilers, 
high steam pressure, and quick-runniug engines, the maximum power obtained on an 
eight hours’ trial corresponds to about 12 indicated horse-power per ton of engines, 
boilers, &c. That is to say, the proportion of power to weight of propelling 
esate is from three and a half to four times as great in the destroyer as it is in 
the cruiser, 
