Page:Popular Science Monthly Volume 92.djvu/962

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��Popular Science Monthly

��An Inexpensive and Effective Water Cooler

IN the usual gas-engine installation the water is circulated through a large tank where it is cooled by radiation. Ordi- narily this process answers every purpose,

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��Perforations Feed pan i

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���Numerous boards arranged in a rack to spread the water for cooling it in the air

but in the case of small ice plants, now becoming rather common, a much greater cooling effect is desired. The accompany- ing illustration shows a simple and yet very effective cooler in which the cooling principle utilized is that of evaporation. The apparatus is easy to construct and the cost is low, as it is made almost entirely of wood.

Briefly stated, the method consists in emptying the heated water into a long, narrow galvanized-iron pan, perforated along each side with a series of small holes. The water drips in fine streams through these and falls on a board inclined toward one side, which becomes thoroughly and uniformly wet on its upper side. The water then trickles off the lower edge onto a similar board inclined in the opposite direction. The wetting action is here repeated and the water falls onto a third fjoard, and so on for twenty or thirty drops, according to the cooling capacity desired. It is finally caught by another galvanized iron pan at the bottom, from which it is pumped for use again.

Aside from its cheapness and ease of

��construction, the wood has a distinct advantage over metal in that the water spreads out in a uniform layer, whereas on metal the tendency of the water is to trickle down in small irregular streams.

The cross-sectional diagram clearly shows the relation of the sloping boards and the two pans, while an idea of the general appearance will be gained from the perspective view. When used on the shady side of a building, in a region where the humidity is low, the evaporation is rapid and the cooling effect really re- markable. — John D. Adams.

��Renewing a Worn Artist's Brush by Repointing It

THE points of sable or camel's-hair brushes such as are used by artists rapidly wear away, thus rendering them practically worthless.

An apparently worthless brush may be restored by dipping the bristles in glue, pointing it as well as possible at the time. When thoroughly hardened the brush is repointed on a sharpening stone the same as if it were a steel point. It can be done even more rapidly by holding against a slowly revolving emery wheel. The glue is then dissolved by immersing in hot water. — L. B. Robbins.

A Spring Lock for the Cover of a Garbage Can

THIS lock is for attaching to an ordinary garbage can, built like a pail having a bail. The spring catch, as illustrated, is riveted to the can cover,

SPEING BRASS CATCH

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��Spring catch on a garbage can cover to hold it in place with bail in upright position

the upper part snapping under the bail when it is in an upright position for car- rying. —P. P. Avery.

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