Page:Popular Science Monthly Volume 92.djvu/467

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�� ���NOTHING is more enjoyable and ex- citing than a toboggan slide down some steep incline. No one need forego this pleasure when a toboggan, as here described and illustrated, can be so cheaply constructed.

The essential part is the snow shield, which consists of a curved wooden piece, as shown. An old cheese box without a knot or crack fills the bill to perfection. First carefully taice out the nails and pull out the top and the bottom.

Next procure a good board the same width as the cheese box.

It should be without cracks, and smooth on one side. Nail slats on the board, spacing them 1 ft. apart, and also fasten a strip on the end of the cheese box at the top, after the end of the box has been sawed ofif to the required length. Nail the other end of the box to the board, thus forming the curve or snow shield of the toboggan.

Place the side pieces connecting the top of the curved part with the board of the toboggan, thus forming handles and at the same time stiffening the shield. The top ends of the curve can be further strengthened by putting on strong leather straps. — Peter J. M. Clute.

��A flat board strengthened with two cross pieces makes a toboggan. A curved section from a cheese box furnishes a snow shield

��Place 50 grams, (about 2 oz.) of crystal- lized photographer's hypo in a small cup and add 10 cubic centimeters (100 drops) of water. Place the cup and con- tents on the stove, and in a few minutes the mixture will dissolve, forming a clear liquid solution. Now pour the mixture

into a thin glass tumbler, the temperature of which has pre- viously been raised by dip- ping it in hot water. Set the solution aside and allow it to cool, being care- ful not to dis- turb it. When cooled to room tempera- ture, pick up the tumbler, give it a quick shake, or add a tiny crystal of the hypo, and the dissolved salt will instantly separate in a solid mass of crystals, ap- parently ice. At the same time, the tum- bler which was previously cold, becomes decidedly warm, illustrating the scientific fact that water in freezing liberates heat.

��The Mystery of Freezing Water Instantaneously

TO produce "ice" in the twinkling of an eye, as if by magic, is very simply and easily done. ^

��Stop to Prevent Snow from Entering Under a Garage Door

1ARGE garage doors must swing clear -> of the floor because there is no threshold strip at the bottom and this makes rather a large opening for snow to drift in on a windy winter's day. One owner of a private garage found that this opening caused considerable trouble as the doors faced the direction of most gales. He devised a drop, however, to work

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