Lectures on electricity / by James Ferguson, F.R.S.

  • James Ferguson
Date:
1825
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on electricity / by James Ferguson, F.R.S. Source: Wellcome Collection.

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    3f> EXPERIMENT XV. A Model of a Water-mill turned by a stream of Electric Fire. 56. Set the mill (§ 32. Fig. 3, of Plate II.) properly, near the prime conductor, and place the crooked wire so that its point may be directed towards tlie uppermost side of the great wheel A. Then turn the glass globe by the winch, and the stream of fire that issues from the point of the wire will turn the wheel; and, conse- quently, all the other working parts of the mill. I have often found, that either of these machines will be put into motion when the point of the crooked wire is four inches from the wings of the great wheel. Apd yet my electrical machine is far from being one of the strongest kind. EXPERIMENT XVI. The luminous Glass, or Aurora Borealis. 57. This is one of the finest of all electrical experiments, and owes its invention to Mr. John Canton.—Take the glass A a (Fig. 4, of Plate I.) by either of its ends, and hold the other end to the prime conductor. Then make the room quite dark, and turn the globe of the machine by the winch. On doing this, the glass will be full of electric fire, which will stream and Hash, exactly re- sembling the Aurora borealis, or northern lights in the heavens ; and the flashing will continue for some time after the glass is removed from the conductor. When the flashing ceases, and you continue to hold the glass by either end in one hand, apply the palm of the other hand to the other end of the glass, and the fire will ap- pear within it again. The method of preparing this glass is shewn in § 25. The fire is always within the glass, but adheres in-