940 



Popular Science Monthly 



Twisting a Wire When Pliers Are 

 Not Available 



IF it becomes necessary to twist a wire 

 around an object to serve as a ferrule, 

 or to draw parts together tightly, and 

 pliers cannot be used to get the desired 



Twisting a loop tightly around an 

 object, using a stick instead of pliers 



twist, the method illustrated will be found 

 satisfactory. It is only necessary to make 

 a loose loop around the part for the band 

 and to apply a stick. — A. S. Thomas. 



Making a Plumb- Bob Level 

 of a Wood Angle 



THIS simple form of a plumb-bob level 

 is very efficient and is easily con- 

 structed of material found on any building 

 job. It consists of two pieces of wood 

 fastened to a block to form approximately 

 a right angle. A piece is fastened firmly 

 across the two legs of the angle, and a 

 staple, nail or screweye is put in at the 



A V-shaped frame of wood with 

 a plumb-bob and line attached 

 to be used as a carpenter's level 



point A. Fasten to this a string and 

 plumb-bob. Place the frame on two sur- 

 faces as shown in the drawing. Make a 

 mark on the crosspiece at the point where 

 the plumbline crosses. Reverse the frame 

 so that the leg B rests on one support 

 and C on the other and make a mark on 



the crosspiece where the line crosses. 

 Measure off a point halfway between these 

 two marks and make a permanent mark D. 

 This mark will be crossed by the plumb- 

 line when the frame rests on a perfectly 

 level surface. — B. Francis Dashiell. 



Saving Scrap-Gum When Making 

 Tire Repairs 



IN repairing pneumatic tires save the 

 scrap-gum. This can be returned to 

 the factory for credit. The value of this 

 material when returned depends largely 

 upon the condition of the rubber. The 

 gum should be kept separate and free 

 from foreign material. When unrolling 

 gum or fabrics for cutting, unroll them so 

 that the holland is on top; then roll the 

 hoUand back. Do not destroy the holland, 

 as it may be used to cover tube-plates. 



Measuring Circumference with 

 Typewriter Spacing 



HAVING occasion to measure a cir- 

 cumference that figured out to tenths 

 of an inch, and not having a rule marked to 

 these divisions, I tried the following means 

 of overcoming the difficulty. Going to a 

 typewriter, I made a row of periods, with 

 each tenth one a comma to show full 

 inches, thus: 

 1... 2 3 



This gave me a rule marked in tenths, 

 also one that could be bent around shaft- 

 ing, collars, etc. As nearly all typewriters 

 make ten spaces to the inch it is an easy 

 matter to accomplish what seems to be a 

 difficult job. — J. Claude Crews. 



A Durable Dead Black for the 

 Inside of Cameras 



THE dead black used by most camera 

 manufacturers, the composition of 

 which has long been considered to be a 

 secret of the trade, is a mixture of lamp 

 black and celluloid solution, the latter 

 being far superior to shellac varnish for the 

 purpose. The lamp black is stirred in and 

 thoroughly incorporated with the liquid. 

 There is no difficulty in making the celluloid 

 solution. Old photographic films may be 

 cleared of adhering gelatine, washed and 

 dried, then shredded as fine as possible. 



A solution is then made by dissolving 

 acetate in amyl to the consistency of 

 syrup and thinning down the acetone with 

 it. — H. G. Gray. 



