Page:Popular Science Monthly Volume 53.djvu/67

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the bulky flaxen cord previously used, and it offers so much less resistance to the wind that two kites on a wire line will bear the instruments to as great a height as six of the same size on a flaxen line. Still, owing to weight and wind, the droop in the wire is so great that about two miles of it are required for one mile of ascent.

The wire had also some disadvantages, one of which was rust. This has been overcome by an arrangement by which oil is dropped upon it as it is wound in. Another difficulty last year was the startling shocks the men holding the line got from the electricity it

PSM V53 D067 Clamp for tandem kite attachment.png
Aluminum Clamp, which attaches kite string to wire of trunk line in a tandem.

brought down from the sky; but no handling is now required, and the machine carries all the sparks harmless to the ground.

No attempt is yet reported on the part of the Blue Hill people to investigate specially the electrical phenomena since those by Mr. Alexander McAdie at this observatory in the summer of 1885, and again in 1891 and 1892; but certain gentlemen near New York, assisted by Mr. W. A. Eddy, on the night of November 13th, sent up by means of kites an electrical collector (presumably a plate or wire net of copper), a small copper wire forming the conductor. The first spark was obtained between fifteen and twenty-five minutes after the kites were sent up, and when the collector was at a height of three hundred and eighty-one feet. The time was between ten o'clock and midnight. The temperature at the earth's surface at the time was 38° Fahr., while a self-registering thermometer sent up on the kites showed 37° at an elevation of four hundred and twenty feet—the sky being clear, or nearly so. Quite likely the records of electrical phenomena at Blue Hill are more full and explicit than this at Bayonne, but neither these nor the theories on the subject have been given to the public.

The first practical use of electricity obtained by means of kites,