used in making binding-posts, etc., as the wood is very liable to split
if a screw is forced into it without a previously-made hole.

Red-hot nails, needles, etc., are easily made to burn holes of desired
diameters. They may be heated in a gas flame or by means of the alcohol
lamp (App. 22). Flat pieces of hot steel will burn narrow slots, and
small, square holes may be made with hot nails.

APPARATUS 26.

_41. To Make Holes in Sheet-Metal._ Fig. 13. Holes may be punched in
sheet-tin, copper, zinc, etc., in the following manner: Set a block of
hard wood, W, on end; that is, place it so that you will pound directly
against the end of the grain. Lay the metal, T, to be punched, upon
this, and use a flat-ended punch. A sharp blow upon a good punch with a
hammer will make a fairly clean hole; that is, it will cut out a piece
of metal, and push it down into the wood. A sharp-pointed punch will
merely push the metal aside, and leave a very ragged edge to the hole. A
punch may be made of a nail by filing its end flat.

[Illustration: Fig. 13.]

APPARATUS 27.

_42. To Punch Holes through Thick Yokes, etc._ As soon as 5 or 6 layers
are to be punched at one operation, the process becomes a little more
difficult than that given in App. 26. If you have an anvil, you can
place the yoke over one of the round holes in it, and punch the tin
right down into the hole, the ragged edges being afterward filed off.
Hold the yoke as in App. 79 or 80 for filing. As you will probably have
no anvil, lay an old nut from a bolt upon the end of the block of wood
(App. 26), place the metal to be punched over the hole, and imagine that
you have an anvil. Very good results may be obtained by this method. The
size of nut used will depend upon the size of hole wanted.

APPARATUS 28.

_43. To Straighten Wires._ It is often necessary to have short lengths
of wires straight, where they are to be made into bundles, etc. To
straighten them, lay one or two at a time upon a perfectly flat surface,
place a flat piece of board upon them, then roll them back and forth
between the two. The upper board should be pressed down upon the wires
while rolling them. If properly done, the wires can be quickly made as
straight as needles.

_44. Push-Buttons._ Nearly every house has use for one or more
push-buttons. The simple act of pressing your finger upon a movable
button, or knob, may ring a bell a mile away, or do some other equally
wonderful thing.