The writer drew the Editor's attention to a series of experiments that Yarrow and Co. of Poplar, had conducted that demonstrated that the power required to propel boats of different sizes varied considerably at different speeds. The experiments had been carried out on two torpedo boats of different sizes one being length 100 feet, beam 12 feet six inches; displacement 40 tons, and the other length 86 feet, beam 11 feet; displacement 33 tons. The results of the experiments were as follows (1). 248 indicated horsepower was required to achieve a speed of 15 knots with the 40-ton vessel; 277 indicated horsepower was required to achieve a speed of 15 knots with the 33-ton vessel. (2). 394 indicated horsepower was required to achieve a speed of 18 knots with the 40-ton vessel; 390 indicated horsepower was required to achieve a speed of 18 knots with the 33-ton vessel; (3). 540 indicated horsepower was required to achieve a speed of 21 knots with the 40-ton vessel; 510 indicated horsepower was required to achieve a speed of 21 knots with the 33-ton vessel.