Page:Popular Science Monthly Volume 91.djvu/799

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Popular Science Monthly

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��A Lead Pencil Sharpener with Dust Collector Box

THE pointer consists of a box in which a wood cylinder is placed having a diameter almost the same as the box opening is wide. This roller is hung on a shaft, one end of which extends out for a thumb hold. Sand- paper is tacked to the surface of the roller. After pointing the pencil the roller is turned to deposit the dust in the box. — G. P. Lehmann.

���Sandpaper covered rol- ler for pencil sharpener

��A Stain for Giving Wood a Brilliant Rose Color

WOOD and vegetable ivory can be colored rose-red without much diffi- culty by chemical precipitation. The color resulting from the following baths is very brilliant and uniform. The first bath con- sists of a solution of eight parts of potassium iodide added to a hundred parts of water; the second, two and a half parts of corrosive sublimate to a hundred parts of water. The wood is immersed for a few hours in the first bath, then placed in the second bath, where it acquires a beautiful rose-red color. After drying, it should be varnished. Both baths can be used repeatedly before renewing them. — Herman Neuhaus.

��Repairing a Fast-Pin Hinge Where Riveting Is Impossible

SOME time ago, having lost the key to my toolbox, I had to file off and with- draw the pins of the hinges to open the box. The hinges themselves were all

���Cut off here

��An ordinary wire nail sharply bent and used for a hinge pin

riveted on. When I attempted to replace the pins I found it impossible to rivet them, because I could not hit them hard enough to form the rivet.

��I used the box with loose pins until an easy solution occurred to me. This was to take long spikes, slip them through the hinges as far as they would go, and bend them sharply with strong pliers, as shown in the illustration, after which they were cut off half-way on the bend.

This same method can with advantage be used in cases where it is desired to change a loose-pin butt into a fast-pin one, and where riveting is impracticable.

��Drawing Perspective Views by Mov- ing Paper on Board

IN the illustration is shown a method of drawing perspective views of machinery, buildings and the like. Instead of using a protractor it is only necessary to remove all the thumb tacks except the one shown at A, which is used as a fulcrum. When the sheet of paper is moved to the desired

���Swing drawing paper on board to get the proper " perspective lines with T-square

angle of projection, proceed with the T- square and the triangles just as for plain horizontal and vertical lines. After the paper is set to the required angle the thumb tacks are replaced.

While the paper is still set square with the drawing-board, the border lines should be drawn. The one marked B is used in connection with another marked C on the board for setting the paper, or a protractor may be used direct, if there is one at hand. The general layout should be penciled first. An angle of about 15 or 20 deg. is the greatest that is practicable with this method. — J. B. Murphy.

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