Mr. Tesla's Invention

TO THE EDITOR OF THE HERALD:—

In a special despatch in your issue of to-day a well known improvement of mine is referred to as if invented by German engineers. This is all the more disappointing to me as I have been virtually ridiculed for advocating the idea. I refer to the electric driving of propellers which I have recommended as particularly suitable for ocean liners.

A common mistake of my critics was to assume that the adoption of the scheme would necessitate a great increase in weight, but it is not so. The turbo-generators would weigh much less than the current marine engine, and the motor designed for very high peripheral velocity would be light. Numerous auxiliary engines, the lighting plant, head shafting, pulleys, supports and miles of pipe could be done away with, thus diminishing the total weight and saving power besides. Much more energy could be obtained from the prime movers and the propellers could be made to work with the highest efficiency. In making this change on the existing vessels the boiler plants could remain intact. The gain in speed would be considerable.

I cannot agree with the opinion unanimously expressed by the Association Shipbuilders and Shipbuilding that "electric power transmission affords the only solution," for, as stated in a previous letter to the Herald, I have discovered another and better one.

NIKOLA TESLA
NEW YORK, Nov. 30, 1907.