q Amateur - 

 Electrician 



-And Wireless Operator 



A Quick Action Electric Switch 

 for Photographers' Use 



IN doing some work around my dark room 

 I felt the need of an electric switch 

 which would 

 work more swift- 

 ly and easily than 

 those sold by sup- 

 ply houses. The 

 illustration 

 shows a single 

 pole switch that 

 met my demands 

 for something 

 delicate and in- 

 stantaneous in 

 action and it was 

 constructed quickly. The base A was made 

 of well shellacked wood 4 in. long 2 in. wide 

 and 1 in. thick. The hinges B fasten the 

 block C to the base block A. The block C 

 is about 23^2 in- long an d about 1% in. 

 wide. A handle D is fastened with screws 

 to the piece C. The two terminals E 

 consist of brass screws and washers on 

 pieces of bronze or copper. Across the 

 face of the block C is a strip of bronze 

 tacked in place with small brads. Closing 

 the block C brings the strip of bronze in 

 contact with the terminals E which com- 

 pletes the circuit. — Virgil R. Tharp. 



A quick acting single pole 

 single throw electric switch 



Making an Electric Searchlight for 

 a Motor-Boat 



A RELIABLE searchlight is a necessity 

 for motor-boating at night, especially 

 in crowded waters. The searchlight illus- 

 trated is for use on small craft not equipped 

 with a generator and is operated indepen- 

 dently of the ignition batteries. 



For the light unit, purchase one of the 

 hand lanterns that operate on one dry cell. 

 Many types are on the market, but for this 

 use it is necessary to select one with a large 

 reflector. Procure a tin can into which 



the reflector of this lamp will snugly fit. 

 To this can rivet a swivel arrangement, as 

 shown. It is made from 3^-in. nickeled 

 pipe fittings and it consists of a flange, 

 tee-joint, two ells with flanges and three 

 short lengths of pipe. The flange is riveted 

 to the side of the can and a hole is punched 

 in the can so that the wires which come 

 up through the piping may pass through. 



The reflector and lamp are connected 

 with the wires, a switch on the back of the 

 can forms a handle to move the search- 

 light, and the reflector is soldered into 

 place. The flanges on the ells are screwed 

 to the deck and a hole is bored under 

 one to pass the wires through. The wires 

 should be well taped to prevent abrasion 

 and a short circuit. 



The battery for this light consists of two 

 or three dry cells connected in parallel. 

 The cells should be placed in a wood or 

 pasteboard box, connected, then com- 

 pletely covered with melted pitch or paraf- 

 fin. This effectively prevents short circuits 

 and prolongs the life of the cells by her- 

 metically sealing them. The wiring be- 



LOOSE THREADS 

 ALLOW TURN- 

 ING OF LAMP 



An electric searchlight for a motor-boat 

 wherein only dry cells of battery are used 



tween the batteries and light should be 

 rubber-insulated . 



The light thrown is very powerful. If 

 three batteries are used they will usually 

 last a whole season. This is due to their 

 parallel connection, which splits the load 

 and lengthens the life. The light on a 

 whole is neat and serviceable. A good 



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