WATER-SPEED MARVELS.

Oamaru Mail, Volume XLIV, Issue 14001, 4 March 1920, Page 2

WATER-SPEED MARVELS.

BELL-BALDWIN BOAT.

Seventy miles an hour, says the "Illustrated World," is the wonderful performance achieved by the hydro- . drome, the new water-speed marvel, developed Jay T>r'i Alexander Graham Bell, the telephone inventor, and Mr F. W. Baldwin, at the former's summer home and laboratory at Baddeck, Nova Scotia. It- is one of the great facts which the Uniled States Navy Department will consider in looking to this new development in vessels for a solution of some pressing naval problems. The hydrodrome consists of a.. 'cigar-shaped hull sixty feet long, with, outrigger pontoons, sixteen feet long, decked to the main structure. On top are two Liberty motors, eac-h with a four-bladed air-propeller. The whole looks somewnat like a combination airplane and dirigible, resting on the water. But when the craft moves, it discloses something new. .It crawls up out of the water and apparently rests thereon upon sets of stilts. These "stilts," actually streamline struts, descend from beneath each wing-like deck, and form the stern, where they hold hydro-foils, or cambered planes, which act on and are acted upon by (the water exactly as an airplane's wings are acted on by the air. When H.D.4—as this craft is called —is going at twentymiles an hour she has her hull clear out of the water. At seventy miles an hour, she is away above the water, and her entire weight of over 11,000 pounds is supported by less than four square- feet of hydrofoil.

"That is rather paradox," says Dr Bell. "For the total displacement in water of the four square feet of hydrofoil and the struts which connect them cannot bo more than a few cubio inches. A water craft weighing over 11.000 pounds with no displacement to speak of is rather a novelty. . . With, the hydrodrome, the faster it goes, the. greater the resistance on the hydrofoils; but, the faster it goes, the less hydro-foil "there is in the water to cause resistance. It is this substitution,of air resistance for water resistance, while keeping the power of the relatively dense water to support the, whole, which gives D.H.4 its speed." Mr Baldwin anticipates being able to build a hydrodrome big enough, strong enough, and speedy enough, to -cross from New York to London in a day !