Thermo-met′ric a-larm′.
An instrument to release an alarm when a dangerous heat is reached in an apartment. A form of fire-alarm. A bent glass tube with a bulb at each end, one of which with a part of the stem contains ether; the other with a part of the stem containing mercury and open to the external air. The tube is poised on its center by gravity. Should the temperature be raised by the presence of fire, the ether would be expanded, the mercury driven into the bulb, the instrument tipped over on its axis, and the alarm sounded. See thermal alarm; thermo-electric alarm; thermoscope; thermostatic alarm. |
| Thermometric steam-gage. |
