Popular Science Monthly 



391 



Doing Your Tire Repairing at Home 

 with an Electric Vulcanizer 



AN electric vulcanizing outfit which 

 enables the automobile owner to make 

 his own casing and inner-tube repairs in 

 twenty minutes or less, has been placed on 

 the market by a western manufacturer. It 

 consists of a vulcanizer with a curved 

 surface for casing and a flat surface for 

 inner tube repairs. Repair materials pro- 

 vided consist of Para rubber, cement, wax 

 paper and emery cloth. The vulcanizer 

 works on a one hundred and ten-volt 

 electric circuit. 



In repairing a cut in the casing, gasoline 

 and the emery cloth are used to clean the 

 damaged part. With the cut spread open, 

 two heavy coats of cement are applied and 

 are allowed to dry. After this the hole is 

 filled level with small pieces of rubber gum 

 and the repair covered with wax paper. 

 Then the vulcanizer is ready to be attached. 

 This is done by applying the curved portion 

 against the repair and fastening it securely 

 to the casing by placing a chain around the 

 felloe of the wheel and drawing up the 

 thumb-nuts. 



After connecting the vulcanizer to the 

 current supply, the button is pressed and 

 the repair proceeds automatically, the 

 electric circuit being opened when sufficient 

 heat has been generated to prop- 

 erly vulcanize the rubber. For 

 extra deep or large cuts the 

 button is pressed a second 

 time after the vulcanizer 

 has cooled off. 



In oval : Vulcanizing 

 the tire casing with the 

 curved side next to the 

 tire. Below: Vulcaniz- 

 ing the inner tube with 

 the flat side to the tire 



Determining the 

 height of a spire 

 by multiplying 

 the reading of 

 the instrument 

 by one-half of 

 the length of 

 the spire's base 



Measuring Sloping Roofs Without 

 Breaking Your Neck 



THE instrument shown in the illustra- 

 tion above is designed to enable a 

 workman to determine the vertical and 

 sloping height of a spire quickly and 

 'without risk. 



It is placed against the sloping 

 sides of a roof, the pivoted 

 pointer is made level, and a 

 basic number by which to 

 calculate the height of the 

 roof is immediately ob- 

 tained. For example, the 

 number given by the in- 

 strument when fitted 

 against the side of the 

 triangle shown in the photo- 

 graph is twenty. By multi- 

 plying the number of feet in 

 the base of the triangle by 

 twenty we will immediately 

 obtain the vertical height, or the 

 altitude, of the triangle in inches. 

 The angle at which the side slopes is 

 also given, and for the triangle in the 

 photograph, this is roughly sixty 

 degrees. Hence it is necessary only to 

 measure the base of a church spire and 

 use this instrument to obtain its 

 height. The sloping height may then 

 be figured from the simple well-known 

 formula for right triangles. 



