The Electrical Experimenter, August, 1916, page 253:

A  100 K.W.  Radio  Frequency  Alternator.
100 kw alternator

    The photograph with this article is of one of the most remarkable alternators ever built. It was developed in the research laboratory of the General Electric Company. At a speed of 3,600 revolutions per minute, it has yielded an output of 100 k.w. with a frequency of 50,000 cycles per second. The voltage developed is rather low, but this may be changed to suit any requirements by means of a variable ratio transformer used with the machine. This remarkable electrodynamic mechanism represents one of the first of the really large machines of its type which will be used more extensively for high frequency work in the future. It has been proven in practice--notably at radio station at Tuckerton, N.J--where the Goldschmidt radio frequency alternator has been used, that this type of alternator is the most efficient for work under all conditions. They are constant in their output, and now means have been perfected whereby they can be very easily controlled by the human voice for radiotelephonic purposes. It will possibly result in the design of similar alternators capable of delivering high frequency alternating current, with an output of several hundred kilowatts.
    Great credit is due to Mr. Alexanderson, of the General Electric Company's research staff, who has spent much time and study on the perfection of designs for these radio-frequency alternating current generators with a large output, since it has only been in the past few years that such machines have been operated successfully. There were a number of these high-frequency alternators built several years ago by Dr. Fessenden, delivering as high as 200,000 cycles per second, but the output was generally limited to a few kilowatts.
    By means of the wonderful vacuum trigger tubes, also developed by the company building these new high power alternators, the output can be exactly and perfectly controlled.