Santos-Dumont's Speed

TO THE EDITOR OF THE HERALD:—

I notice from the Herald of even date (page 8) that Santos-Dumont managed to attain a speed of 32 miles instead of 48, as I calculated. I assumed an efficiency of 64 per cent for propeller and inclined plane combined. If his motor was driven at full power the efficiency was only 43 per cent, and it is more likely to be true than the highest theoretical figure I assumed. I wish that he had made a good test and come close to 48 miles, as I calculated to give my theory a better test. But you see that the old notions of the hydroplane cannot possibly be true. Santos- Dumont can still win the bet if he will follow my suggestion.

NIKOLA TESLA
NEW YORK, Oct. 24, 1907,