and upper fittings of aluminum, 4 per cent. nickel alloy, while the bottom plating is of bronze. The stern, frames, floor-plates, stiffening-angles, bilge-stringers, inverted angle-bulbs, under-*deck beams, the two deck beams inclosing mast, tie-plates round mast, stepping-socket, bed-plate fittings, and supports and chain-plates are of steel. All the rivets are of bronze, thus completing an intimate association of the three metals, which was followed in a short time by inevitable general corrosion.
Advocates of aluminum as a fit metal for use in shipbuilding point out that no effort at insulation of any kind whatsoever was made, not even the simple precautions which would have been insisted on in an ordinary case of steel and bronze construction. Defender was built with only one purpose in view—the winning of a series of races. Her subsequent proceedings were a matter of no interest to her owners and builder. Had she been built of steel throughout she would have cost about half as much as she actually did, and would have been good for fifteen years of hard sailing if built up to Lloyd's rules. But she might, in that case, have failed to fulfill her only reason for existence—the beating of Lord Dunraven's Valkyrie III.
The scientist who will invent some alloy to combine with aluminum which will make the metal free from corrosion when immersed in salt water will confer a great boon on the builders of racing
