Nikola Tesla - Free-Energy Devices

8 INVENTIONS OF NIKOLA TESLA.Now that opinion is turning so emphatically in favor of lowerfrequencies, it deserves special note that Mr. Tesla early recognizedthe importance of the low frequency feature in motorwork. In fact his first motors exhibited publicly and which, asProf. Anthony showed in his tests in the winter of 1887-8, werethe equal of direct current motors in efficiency, output and startingtorque were of the low frequency type. The necessityarising, however, to utilize these motors in connection with theexisting high frequency circuits, our survey reveals in an interestingmanner Mr. Tesla's fertility of resource in this direction.But that, after exhausting all the possibilities of this field, Mr.Tesla returns to low frequencies, and insists on the superiority ofhis polyphase system in alternating current distribution, need notat all surprise us, in view of the strength of his convictions, sooften expressed, on this subject. This is, indeed, significant, andmay be regarded as indicative of the probable development nextto be witnessed.Incidental reference has been made to the efficiency of rotatingfield motors, a matter of much importance, itthoughis not theintention to dwell upon it here. Prof. Anthony in his remarksbefore the American Institute of Electrical Engineers, in May,1888, on the two small Tesla motors then shown, which he hadtested, stated that one gave an efficiency of about 50 per cent,and the other a little over sixty per cent. In 1889, some testswere reported from Pittsburgh, made by Mr. Tesla and Mr.Albert Schmid, on motors up to 10 H. p. and weighing about850 pounds. These machines showed an efficiency of nearly 90per cent. With some larger motors it was then found practicableto obtain an efficiency, with the three wire system, up to ashigh as 94 and 95 per cent. These interesting figures, which, ofcourse, might be supplemented by others more elaborate and oflater date, are cited to show that the efficiency of the system hasnot had to wait until the present late day for any demonstrationof its commercial usefulness. An invention is none the less beautifulbecause itmay lack utility, but it must be a pleasure to anyinventor to know that the ideas he isadvancing are fraught withsubstantial benefits to the public.