It is often necessary for the amateur scientist to transpose a temperature reading from the Fahrenheit to the centigrade scale, or vice versa. This is easily accomplished by means of the diagram without the use of a formula. The centigrade readings are given on the horizontal axis and the Fahrenheit readings on the vertical axis. The temperature readings are the same at minus 40 deg. and from that point on the Fahrenheit readings equal nine-fifths of the centigrade plus 32. This reading is instantly seen by the scale.—Contributed by James F. Boyd, Ann Arbor, Mich.
Protecting Plans in a Shop
The magazines I used in the shop, for making a few things from plans, became so soiled that they were unfit for the library. I now keep them clean by using a covering made of an old picture frame from which the back was removed and a plain glass inserted in its place. This is placed over the magazine or other plans on the bench and keeps them clean, dustless, open and flat.—Contributed by H. J. Blacklidge, San Rafael, Cal.
Homemade Eyebolts
Many times one has use for an eyebolt when there is none at hand. Eyebolts of almost any size can be quickly made of a spring cotter. Simply thread the end, as shown, and use a nut and washer.—Contributed by Chas. G. England, Washington, Pa.
To Keep Tan Shoes from Turning Dark
Tan-shoe polishes seem to rub the dirt into the leather and to darken it in a short time. Tan shoes can be kept clean and well polished without losing their original bright tan color if treated in the following simple manner. Instead of using tan polish on a new pair of shoes, dampen the end of a soft clean cloth, and rub a small portion of the leather at a time with the moist end and then rub briskly with the dry end. In this way tan shoes can be kept clean and nicely polished like new.—Contributed by John V. Voorhis, Ocean Grove, N. J.
A Finger-Trap Trick
It is easy to fool one’s friends with the little joker made to trap a finger. It consists of a piece of paper, about 6 in. wide and 12 in. or more long. To prepare the paper, cut two slots in one end, as shown, and then roll it up to tube form, beginning at the end with the cuts, then fasten the end with glue. The inside diameter should be about ¹⁄₂ inch.