Page:Popular Science Monthly Volume 88.djvu/321

Rh celluloid should be placed between them and the end papers to keep the leaves from absorbing moisture and becoming wrinkled.

The easiest way to letter the cover of the book is to make a stencil of the paper cover of the magazine, as this will save the labor of laying out the letters. Lay the cover paper upon a hot plate and saturate it with paraffine wax. Wipe off the surplus wax while it is still hot. Lay the waxed paper upon a piece of straw board and cut the letters out, stencil fashion, using the sharp blade of a penknife. Use a good waterproof India ink and a stiff brush from which surplus ink has been removed. Draw the brush inward from the edges of the cut out letters. The letters may be finished by filling in the blank spaces with a pen.

SANDPAPERING block that automatically adjusts itself to both convex and concave surfaces of any radius is very easily constructed by using a piece of rubber packing for the face and glueing to the back or fabric side wedge-shaped strips of hard wood of the general dimensions shown in the drawing. These strips should be about 1-32 inch apart where they fasten to the rubber, so that the face will bend easily.

The sandpaper is folded over the block in the usual way and with very slight pressure the face will conform to the surface to which it is applied.

VERY convenient instrument which may be used to repair punctured tires can be made from a common button hook. Straighten or cut off the hook part with a pair of pliers. Saw a slit about ⅛ inch from the end up the stem of the hook with a hack saw and round off the ends into a fairly sharp point. With a knife cut all the sharp edges from the slit so it will not tear the rubber bands. Make a hook as shown in drawing, and passing the rubber band first through the slit and then over the hook enough times to fill up the hole in the tire, dip the rubber and hook in tire cement and push through hole. Unhook the rubber band and draw out the hook carefully with a twisting motion so as not to remove the rubber band. Cut off the protruding rubber and you will have your puncture repaired in excellent shape.

ROKEN drills and end mills should not be thrown away, as they will be found useful if a special socket is to be made for the lathe or miller, when a drill or end mill is to be held.

By grinding the tang off, it can be turned around in the socket to ascertain if the taper has a bearing the whole length. If a drill or end mill is used without thus changing it, the tang will prevent its being turned around.