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conductor. The purpose of the thermostat is to prevent the freezing of the zinc solution in the bottles, which it does by the automatic lighting of the lamp upon it; the heat from this lamp being sufficient, in the confined space within the meter, to accomplish the purpose desired. The thermostat, Fig. 27, consists of a block of wood to be secured against the back of the meter. Attached to one end
Fig. 27.—Thermostat.
of this is a lamp socket, one wire from which is attached directly to the conductor leading through the meter, the other being connected to an adjustable metallic screw on the side of the socket. Near this screw is one end of a strip of brass to which is riveted a companion strip of steel, the opposite end being secured to
