Part 23 (1/2)

If you magnetize a sewing-needle by rubbing it on a fairly strong magnet and float it on the water, it will make an extremely sensitive compa.s.s; and if you place two needles on the water at the same time, you will see them slowly approach each other until they float side by side, that is, if they do not strike together so heavily as to cause them to sink.

THE BRIDGE OF KNIVES

Three knives may be supported by their handles in the following manner: Place three gla.s.ses in a triangle, each side of which must be about the length of one of the knives. The blade of the first knife should rest on the blade of the second, by pa.s.sing over it near to the point where the handle and blade are joined; the blade of the second pa.s.sing in the same manner over the blade of the third, which is to be made to rest on the blade of the first. The handles being then carefully placed upon the gla.s.ses, a bridge is formed strong enough to bear a considerable weight.

TO BALANCE A COFFEE-CUP ON THE POINT OF A KNIFE

The articles necessary for the performance of this trick are very simple, a dinner-fork and an ordinary sized cork being all that are needed. Fix the cork firmly in the handle of the fork, then stick the fork into it so that two p.r.o.ngs shall be on each side of the cup handle, and slope the fork in such a way that its handle will come under the bottom of the cup. The heaviest weight being thus brought underneath, you can hold the cup on the point of a knife, if you very carefully find the exact place on which it will balance.

As the surface of the cup is usually glazed, the hand which holds the knife must not tremble, or the cup will slip off.

You may also obtain the same result by using two knives instead of a fork.

THE OBSTINATE CORK

Take a small cork and ask some one to blow it into a fairly large sized, ordinary bottle that has a neck.

This seems to be quite an easy matter. The one who tries it will probably blow as hard as possible upon the little cork; but, instead of going into the bottle, as expected, it will simply fall down. The harder the puffs or blows, the more obstinate the cork will appear to be; and even if the effect of blowing gently be tried, it will be of no use; the cork will not go into the bottle, much to the amus.e.m.e.nt of those who are watching. The reason why the cork will not go in is this: The bottle being already full of air, when the cork is blown, more air will be forced into the bottle, and consequently the air inside will be greatly compressed and will simply force the cork back.

The following is a simple way of overcoming the difficulty: Instead of trying to force the cork through the compressed air in the bottle, just the contrary should be tried, that is, some of the air should be sucked out of the bottle; this being done, the bottle will become partly emptied, and when the outside air rushes in to fill up the empty s.p.a.ce, it will carry the cork with it to the bottom of the bottle.

SIX AND FIVE MAKE NINE

This is a simple little puzzle. Take eleven strips of cardboard, lay six of them at exactly equal distances on the table, and ask one of the company to add the five other strips and yet only make nine. It is done by placing six of them parallel to each other--the others are used to spell out the word nine.

[Ill.u.s.tration]

THE VANIs.h.i.+NG DIME

Stick a small piece of white wax on the nail of the middle finger of your right hand, taking care that no one sees you do it. Then place a dime in the palm of your hand and tell your audience that you can make it vanish at the word of command.

You then close your hand so that the dime sticks to the waxed nail.

Blow on your hand and make magic pa.s.ses, and cry ”Dime, begone!” Open your hand so quickly that no one will see the dime stuck to the back of your nail, and show your empty hand. To make the dime reappear, you merely close you hand again and rub the dime into your palm.

TO LIGHT A s...o...b..LL WITH A MATCH

Roll a s...o...b..ll and put it on a plate. While rolling, contrive to slip a piece of camphor into the top of it. The camphor must be about the size and shape of a chestnut, and it must be pushed into the soft snow so as to be invisible--the smaller end uppermost, to which the match should be applied.