Page:Popular Science Monthly Volume 90.djvu/159

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Popular Science Monthly

��143

��for a lock-nut. The ball was composed of ground cork held together with a water- proof adhesive and molded into shape. These balls cost considerably less than a rubber bulb. The arrangement worked

��the nature of the article are all that would be necessary; as, for instance: Ernest, see Page 59 — Diagram; Frank, Page 64 — ■ Mill, etc. — John Hoeck.

���A cork ball placed on the flush-box valve wire instead of a rubber ball

perfectly and the lasting qualities of the cork were superior to those of the rubber. A little leakage appeared at first, but after several days the ball had shaped itself to the seat and the joint was water-tight. A small portion of vaseline rubbed on the seat and the ball aids in making the joint close fitting. An accurate record of the lasting qualities may be kept by placing the date of its insertion on the ball with waterproof ink. — L. S. Uphoff.

��Why the Tread on Repaired Tires Fails to Stick

TROUBLE is often experienced in getting the tread to stick on small repairs. This may be due to any one of several reasons, the most common of which is that the cement has been applied over wet fabric. The moisture in the fabric, even if very slight will blow the tread loose. Another common cause for loose treads is the failure to roughen up the old carcass sufficiently. In this case the cement will not hold properly and after a few miles of running the repair will separate. It is also well to make sure that proper pressure is being applied to the repair when it is curing.

��Solution for Cleaning Steel Wire

THE wire parts should be run in a tumbling barrel with about 2 oz. of castile soap and enough ground pumice stone to make a thin mud. After the parts are cut down until all rust and scale are removed, they should be washed in hot soap solution and polished by tumbling with soap solution and steel balls; or a fairly bright polish can be obtained by tumbling in dry sawdust with a little flour of pumice.

��Photographic Focusing Table for Hand- Cameras

FOR those using hand-cameras with which it is necessary to depend on the scale attached for determining the proper focusing point, the table given is of great value. It is not, however, of value to those who use "box" or other types of cameras having a fixed focus or standard focus. The table is especially designed to deter- mine the proper point on the focusing scale

Distance of farthest point (of object)

��An Indexing Hint for Readers of Current Magazines

ON looking through a magazine a reader will often see an article of special interest which he would like to read again or one which he would like to call to the attention of some other person. Much time would be saved if a short note were made on the back cover or on the third page of the magazine, or in any other particular spot selected for the purpose. Simply the page number and the name of the person interested with perhaps a word to denote

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��Table by means of which the average focusing point on the scale may be quickly determined

of the camera at which the pointer must be set when it is desired to photograph two objects, one nearer than the other, and to have both in sharp focus.

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