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Page:Popular Science Monthly Volume 90.djvu/144

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��Popular Science Monthly

��that we are working in outlines almost exclusively, although occasionally some suggestion of translucency may be intro- duced with good effect. Excellent "still life" studies may be made from flowers and foliage arranged in clear, cut-glass bowls or vases. Obviously, there is a wide choice of subjects, but heavily opaque objects, without beauty of outline to recommend them, should be strictly avoided.

The question of printing out these shadow photographs effectively must be left to personal decision. Sensitized papers are obtainable nowadays in so many varities of tint and surface-texture that the most exacting requirements can usually be met. If the object in view is a close imita- tion of a real silhouette, it may be gained by using a smooth-surface bromide paper which gives strongly contrasted black and white effects. — Percy Collins.

��To Sharpen Skate -Runners with a File

THE following is a good way to sharpen steel skates having soft runners. Take two pieces of soft wood, about 2)^2 ii^- long and I in. square and fasten them securely I in. apart on a workbench or table as shown. Secure another piece lo in. long, 3 in. wide and i in. thick, to the bench-top about 6 in. from the first pieces. Clamp the»skates to these cleats the same as you would on the soles of the shoes, and

���Clamping skates to a bench-top to hold r them securely for filing the runner surfaces

sharpen them with a lo-in. file. File in one direction only, to keep from spoiling the file-teeth. This method is quick, and a much better edge can be obtained by it than by grinding. — George Wasserberger.

���Repairing the Torque-Rod Support on an Automobile

THE drawing illustrates how the forward end of an automobile torque-rod is supported. Trouble was experienced at this point on a rather low-priced car, and after examination it was found that the parts were badly worn. The plungers A , placed on both sides of the ball-end of the radius-rod, were case- hardened to avoid being worn quickly from the ac- tion of the ball-end. The support-casing, however, was made of cast-iron. This being compara- tively softer than the hard- ened plungers, wore a great deal more rapidly. Thus an unnec- essary clearance between the plungers and casing was made which was found to be 3^8 in. at some points, and this was the cause of the trouble.

To eliminate it the entire assembly was removed from the car and the casing rebored to a somewhat larger diameter. To allow for this increase, bronze bushings were pressed over the plungers as shown. This repair eliminated the trouble, and gave the added advantage of causing the wear to be carried by the bushings, which could be readily and cheaply replaced. — Adolph Klein.


��Bushing the sliding parts of a torque-rod

��Repairing Molded Rubber Goods with Quick- Cure Cement

THE quick-cure vulcanizing cement is excellently adapted for repairing molded goods and other rubber articles which would not stand prolonged exposure to the heat of vulcanization. Hot- water bottles, rubber boots, bands on date stamps, etc;, are examples of articles that can be repaired with this cement.

��A Ground Color for Applying Mahogany Stain

DISSOLVE permanganate of potash in sufficient water to make a rich crimson shade. Any kind of white wood may be painted with this solution. When dry, apply the mahogany stain and finish in the usual manner.

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