Scientific American Supplement, No. 620, page 39 by Various Authors
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above figure, and heated by a continuation of the steam coil from D.
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CONFEDERATE APPARATUS FOR MANUFACTURING SALTPETER FOR AMMUNITION.
By CHARLES K. GALLAGHER, Washington, N.C.
Any convenient number of percolators, made of rough boards, arranged over a trough after the style of the old fashioned "lye stand," similar to the figure. Into these was placed the earth scraped from around old tobacco barns, from under kitchens and smokehouses. Then water or water and urine was poured upon it until the mass was thoroughly leached or exhausted. The percolate was collected in a receptacle and evaporated, the salt redissolved, filtered, again evaporated, and crystallized from the mother water.
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THE TELEMETER SYSTEM.
By F.R. UPTON.
In this paper, read before the British Association, the author explained that the "Telemeter System," invented by C.L. Clarke, of New York, is a method by which the slow movement of a revolving hand of any indicating instrument may be reproduced by the movement of a similar hand at a distant place, using electricity to convey the impulse. The primary hand moves until it makes electrical contact, thus sending an impulse. It is here that all previous methods have failed. This contact should be absolute and positive, for if it is not, the receiver will not work in unison. The contact could often be doubled by the jarring of the instrument, thus making the receiver jump twice. Clarke has overcome this defect by so arranging his mechanism that the faintest contact in the primary instrument closes two platinum points in multiple arc with it, thus making a firm and positive contact, which is not disturbed by any jar on the primary contact. This gives the instruments a positive start for the series of operations, instead of the faint contact which would be given, for example, by the light and slowly moving hand of a metallic thermometer. The other trouble with previous methods