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4 shipping of water or production of spray. . at high speed, the tendency of the stem is to throw up _ considerable spray at the point where it cuts the water. This in itself may seem some- what insignificant, but when it is re- membered that the drops of watet cut the faces of the crew aft on the deck like hail, and in a breeze ren- ders it amost impossible to stand against it, the seriousness and dis- comfort arising from such prevailing conditions may be realized. This is overcome by making the stem in- stead of raking aft from the water- line, to slope forward, the rake be- ing as much as 2 ft. between the water-line and the extreme forward end of the deck, In the trials car- ried out by the Admiralty the "Des- perate" attained 0.75 knot in excess of that required according to the con- tract, notching 30.75 knots (35.44 miles) per hour with an actual mean speed of 30.428 per hour. In 1899 a new record in speed for this class of craft was established by the "Albatross," also built for the British government, by reaching a speed of 32.3 knots (37.24 miles) per hour, and which record was not low- ered until two years later. The de- velopments that had taken place in the increase of the dimensions and power of previous successive vessels of this type was carried still further, the length of the boat being 227 it. © in, with.a beam of 21 it. 3 in.,. and a draught of 8 ft. 6 in. The machin- ery consisted of the Thornycroft triple expansion compound surface condensing engines with cylinders of 22-in., 33%-in., and two 36-in. bore by 20-in. stroke, and developing 8,000 indicated horsepower, driving twin screws and with: steam raised by a battery of Thornycroft coal-fired boilers. water-tube With the remarkable record set up it was considered that practically the limit in speed in such vessels of this caliber had been attained with re- ciprocating engines. Within the past five years the Parsons turbine has established its capabilities very firm- ly and the experiments of the Ad- miralty having confirmed the utility of this type of prime mover to war- ship practice, when the orders for the construction of the last batch of torpedo boat destroyers were given out to the various shipbuilders of Great Britain, turbine machinery was stipulated. These vessels, of which the "Tartar" constitutes a' unit, are of a new type of destroyer, officially known as the "ocean-going" class, In such craft, when running tHe Marine REVIEW WaATER-TUBE BoILERS OF THE ALBATROSS, THORNYCROFT TYPE. the distinguishing feature being not only high 'speed, but greater cofi- structional strength, heavier displace- ment and greater radius of action, while moreover, coal was eliminated entirely for steam raising purposes im fayor of oil. - Ht was found that with the types of destroyers described the radius of action was not only very limited, but that the limits of lightness had been overstepped. They were not sufficiently strong for service in any but the calmest of weather, there being a tendency in a sea-way for the boats to crumple up and break their backs. which contention "with all. hands. was supported by the mysterious dis- appearance of one or two vessels of this description, such as the "Cobra," Under these circum- stances, it was decided to _ evolve a heavier class of destroyers, no mat- ter if the speed had to be somewhat sacrificed, since it was conceded that the other advantages which would be secured would more than compensate for any reduction in pace. The per- fection of the Parson's turbine com- bined with the high-speed tests that had been obtained in other classes of vessels engined therewith, re- moved any apprehensions regarding MACHINERY OF THE TorPEDO Boat DESTROYER EXPANSION 22, Four CYLINDER, TRIPLE- ALBATROSS. 334%, 36 AND 36 IN, By 20 IN. STROKE,