The introduction of rapid-firing guns of great power and range is claimed by some naval authorities to have reduced very materially the effectiveness of the torpedo boat. Its speed has been doubled in a few years, but it is contended that with the improvement in guns this has been more than neutralised by the greater size it has been necessary to give the torpedo boats in order to provide sufficient space for the machinery and retain the vessel’s sea-going qualities, as the increased size renders the vessel easier to hit. It must be remembered, moreover, that the anti-torpedo boat armament of a modern warship can fire as many as a hundred shots a minute, or several times as many as when torpedo boats were added to the world’s fleets. [Illustration: HIGH-SPEED SEA-GOING TORPEDO BOAT OR GUNBOAT, PROPELLED BY INTERNAL COMBUSTION ENGINES. SPEED 23 KNOTS. _Photograph supplied by Messrs. Yarrow & Co., Ltd._] [Illustration: U.S. DESTROYER “LAWRENCE.” _Photograph supplied by the Fore River Shipbuilding Co._] Some of the Continental powers have been quick to appreciate the value of the torpedo boat as propelled by internal combustion engines, among the most noteworthy examples being those built and engined by Yarrow for the Austrian Government. The “E,” for instance, is 60 feet in length by 9-feet beam, and has a draught of 2 feet 8 inches. She has three screws, and her five sets of these engines give her a speed of 22¼ knots, in spite of her diminutive size, and her radius of action at 11 knots is three times what would be obtainable with vessels of the same size propelled by steam. Another, of the same length, has attained a speed, when light, of 25½ knots, and of 24 knots with a load of 3 tons, and her radius of action at full speed is 250 miles. A somewhat larger vessel from the same makers is 100 feet in length, with a beam of 13 feet 6 inches, and her internal combustion engines give her a speed of 23½ knots. The advantages, and they are very great, claimed for all boats propelled by powerful engines of this type over those propelled by steam engines, are that as the vessels have no funnels there can be no flaming from funnels, with its risk of betrayal of the vessel’s whereabouts; that only half the engine-room staff is required, and that the range of action is three times what it would be under steam.