734 



Popular Science Monthly 



The Automatic Furnace- Watchman. 

 It Prevents Damage to the Boiler 



IN large oil-burning furnaces, so much air 

 is needed to support the oil combustion 

 and to maintain the maximum efficiency 

 that the air must be suppHed in veritable 

 streams. Should the least injury happen to 

 the pumping system 

 and the stream of the 

 air be reduced, the oil 

 would begin to smoke 

 and to burn poorly, or 

 the flame might go out 

 altogether. The oi 

 would then run cold 

 and it would start to 

 flood the fur- 

 nace. If it 

 should reach 

 the bottom 

 of the hot 



, . , . OIL LEVtR TURNS 



boiler, it OFFFUELBY 



5INKING0F AIR 



BELL 



BLLL SUPPORT 

 AND GUIDE 



FUEL PIPE 

 TO FURNACt 



BACK PRESSURE AIR 

 REGULATOR FOR 

 AUTOMATIC SHUT-OFF 



OIL REGULATOR 



would shock 

 the metal and 

 crack it. 

 To prevent such a disaster, Edwin 

 Squires, of Claremont, California, has de- 

 vised a cut-out system which automatically 

 turns off the oil when anything happens to 

 the air supply. It consists of a telescopic 

 air-tank which is operated by pressure of 

 the air itself. This tank, like a commercial 

 gas-tank, contains an upper part, or 

 "bell," which rises and falls with the 

 pressure of the gas inside it. The 

 tank is connected with the air-supply 

 pipe, and the bell of the tank is con- 

 nected by chains with the valve con- 

 trolling the oil supply. 



The air issues from the pipe sur- 

 rounding the oil-jet of the furnace- 

 burner. Here it steadily supplies oxy- 

 gen to the burning oil which issues 

 from the central jet. Should this air 

 supply become reduced, the pressure 

 in the air-tank is lessened. The air in 

 the tank pushes less hard against the 

 bottom of the bell, and it sinks down 

 in consequence. The bell pulls the 

 chain down with it, raising up the con- 

 trolling arm and shutting off the oil. 



A Portable Electric Apparatus for 

 Welding Track Bonds 



IN order to provide a track welder which 

 is cheap enough for the smallest railway, 

 a Western manufacturer has developed a 

 portable apparatus' that consists merely of 

 a resistance element which weighs about 

 two hundred pounds, 

 and an electric fur- 

 nace which weighs 

 sixty-five pounds. The 

 current from the trol- 

 ley is utilized for 

 welding the bonds. 

 With the outfit an 

 electrically -welded 

 bond is obtained 

 which will not de- 

 preciate on ac- 

 count of the ele- 

 ments. In obtain- 

 ing this union, 

 neither an arc nor 

 flame strikes the 

 bond or rail. Thus ■ 

 the danger of in- 

 jury to the bond, 

 rail and eyes is 

 avoided. A heated 

 block of graphite 

 presses against the bond terminal and this 

 produces a true weld, A yoke which sets 

 over the head of the rail and a chain and 

 hook which are fastened to the opposite 

 rail hold the apparatus in a tilted position 

 so that a part of its weight presses the bond. 

 Two hand wheels on the framework ad- 

 just the tilt and vertical position of the 

 furnace, so that the graphite comes into 

 contact with the bond terminal. 



The trolley circuit to the rail is completed 

 by closing the circuit breaker mounted 

 in the center of the rheostat and which is 

 controlled from the handle at the bottom. 



The air bell drops when the air 

 supply fails, pulling up the lever on 

 the oil-valve and shutting off the oil 



A heavy current taken directly from the trolley 

 wires heats the bond and the rail, welding them 

 together with the electrode and five switch-points 



