Page:Popular Science Monthly Volume 92.djvu/628

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��Popular Science Monthly

��Systematic Control of Water in a Bath Tub

A RESIDENT of a small city, wishing to eliminate the final sponging with clear water, necessary to remove the pre-

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PLUGS ^<«^-le:ad pipe:

Two overflows at different levels in the bath-tub, opposite to the faucet

viously applied coating of soapy liquid, decided upon this method of keeping the water constantly clean. As the ten- dency of the water was to carry the soapy matter to the end farthest away from the bath overflow, two overflows and plugs were fitted at the opposite end, thereby providing for two water levels. Regu- lating the flow of water from the bibbs, the bather was able to keep the unclean water constantly moving out of either of the two overflows. — James M. Kane.

��A Cement for Firmly Holding Glass on Metal

ONE of the best cements for joining glass to other substances consists'of a mixture of gum arable and calomel. Its adhesive power is great. It is prepared by putting the very best and purest gum arable into a small quantity of water, and allowing it to stand overnight so that it attains a glue-like consistency. Calomel, or as it is sometimes called, mercurous Chloride or subchloride of mercury, is added in a sufficient quantity to make the mass a trifle more sticky. The ingredients are thoroughly mixed on a glass plate with a spatula. Calomel is a poison, so no more should he made than is required for immediate use. This cement

��hardens in a few hours, but the most satisfactory results are obtained when it is permitted to stand for one or two days. To insure a very serviceable cement it is necessary to utilize only the best materi- als, as inferior grades are useless. Another excellent glass cement is made from gum mastic, powdered isinglass and alcohol.

��Fastening Cases to Railing in Historical Museum

THE method used in placing the manuscript cases in the Historical Society building in a small city is shown in the illustration. It is a good example of economy in space. The gallery running around the upper section of the library room has a pipe railing to keep the clerk from falling off to the lower floor. The upper rail has been utilized to

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���A glass case holding manuscript for exhibition on the guard rail of a gallery

hang cases containing valuable manu- scripts. The framework of the case is of flat iron, the back ends of the top being curved so as to hook over the upper pipe rail.

By using this method the manuscripts are perfectly safe, they are in a good light, and it is possible to examine each one by itself.- James M. Kane.

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