Watchmen's Time Detectors Operated by Batteries or Magneto Generators (1900)
Holtzer-Cabot Electric Company · Holtzer-Cabot Electric Company · leaf 128
n a Dynamo Room. The Holt/.er-Cahot Pressure Indicator performs precisely such service, by means oftwo Signal Lamps — a red lamp to givewarning when Pressure is too high, and agreen lamp to notify when Pressure is toolow—neither lamp burning when Pressureis normal. This instrument, if so placedthat… … OPERATION OF THE INDICATOR. Reference to the accompanying cuts will show that the Indicator consists essentiallyof a core suspended within a solenoid, and balanced between the effect of gravity and the magnetic effect of the solenoid. The terminal numbers 4 and 5 are those of the solenoid in series…
