148 Popular Science Monthly 



An Emergency Battery for Starting A Winding Machine with a 



an Automobile Motor 



AT least 50 per cent of the modern 

 . automobiles use battery ignition. 

 As this system sometimes gives trouble, 

 even in the most expensive cars, I de- 



6 DRY 



-TO POSITIVE TERMINAL CELLS 



-TO NEGATIVE TERMINAL 



A set of dry batteries 'placed under the seat 

 to aid in starting the automobile motor 



vised a method for producing an emer- 

 gency current as shown in the illustration. 

 This consists of six dry cells securely 

 tied together in a triangle shape and 

 wired in series with a 4-ft. length 

 of well insulated copper wire attached 

 to each of the negative and positive 

 terminals. These wires are used to make 

 connections with the storage battery 

 terminals for starting the motor; then 

 they are disconnected. 



The batteries will last a long time for 

 this emergency work. If the storage 

 battery gives too much trouble, remove 

 the filUng caps and make sure that the 

 liquid is y^ in. above the top of the lead 

 plates. Should the level be below this 

 point, add enough distilled water to 

 make up the deficiency. Keep all the 

 battery and wire terminals bright by 

 scraping them with a sharp knife about 

 once a month, and make sure that there 

 is no short circuit in the dashboard 

 switches and that no battery wire or 

 other wire is chafing against any metal 

 to produce a short circuit. In this way 

 a battery may be kept at its highest 

 efficiency. — P. P. AvERY. 



Revolution Counter 



THE winding machine shown in the 

 drawing is of service for winding 

 various types of coils, transformer "pies," 

 etc., in the amateur's shop, or wherever 

 there is no small screw-cutting lathe. 

 The novel feature of the machine is the 

 simple method employed for determining 

 the number of revolutions the spindle 

 makes during the process of winding a 

 coil. 



A piece of round stock, C, Yi in. in 

 diameter and 12 in. long, is threaded 

 3 in. of its length at one end, and has a 

 3/16-in. hole drilled in the opposite end 

 to a depth of Yi in. A three- or four-step 

 set of cone pulleys is made fast to the 

 center of C by keying or with a forced fit. 

 The spindle is mounted in bearings upon 

 standards Z> as shown, and the spindle 

 unit thus assembled is permanently fast- 

 ened to a baseboard 2 in. by 6 in. by 5 ft. 

 A piece of 3/16-in. round rod 3 ft. 4 in. 

 long is then threaded with a die, cutting 

 32 threads per inch for its entire length 

 with the exception of about 2 in. at one 

 end. The stand E is made and fastened 

 to the baseboard at the point shown, 

 and acts as a bearing for one end of the 

 threaded rod. The end of the rod left 

 unthreaded is now inserted in its bearing 

 in the standard E. The opposite end is 

 inserted in the hole drilled in the end of 



A threaded rod on the lathe spindle registers 

 the exact number of turns of wire on the coil 



C, to which it is soldered. A yard stick 

 is mounted in line with the threaded rod 

 and directly above it, and is held in 

 place by two strap-iron standards S>. A 

 loop of fine iron wire is passed around 

 the threaded rod, the ends are twisted 

 together and a small lead weight is 

 fastened to the twisted ends as shown 



