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 



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. 



