172 



Thermometer, Separable Pocket. A steam or vat thermometer 



with a detachable socket cup. [13, 15.] 

 Thermometer, Side Angle. A steam or vat thermometer with 



the lower end bent sideways. [5, 13, 15 17.} 

 Thermometer, Solar Radiation. A mercurial thermometer for 



measuring the maximum temperature attained in the full 



rays of the sun. The tube has a blackened bulb and is 



enclosed in a glass jacket from which the air has been 



removed. [15, 21.] 



Thermometer, Solid Glass. Range up to 500 F. [4, 5, 13, 15, 17.] 

 Thermometer, Sounding. An electrical balance thermometer to 



ascertain the temperature of the ocean at any depth. [13, 



15, 21, 24.] 



Thermometer, Steel Armoured. A chemical or steam thermo- 

 meter, encased in a steel sheath. [4, 5, 6, 15, 17, 21.] 



Thermometer, Stem Divided. Range up to 1,000 F. ; those 

 from 600 F. are nitrogen -filled. [5, 6, 13, 15, 16, 17, 21, 28.] 



Thermometer, Sugar-Boiling. Range, 2oo- 4 oo F. [5, 6, 13, 

 15., 16, 17, 21.] 



Thermometer, Superheater. Range, 2oo-75o F. [5, 13, 15, 



16, 17, 21.] 



Thermometer, Terrestrial Radiation. A spirit thermometer for 

 measuring the maximum temperature reached in conse- 

 quence of the radiation from the earth at night. [13, 15, 17.] 



Thermometer, Varnish Maker's. Range, 2oo-65o F. [5, 13, 

 15, 16, 17, 21.] 



Thermometer, Vulcaniser. Range, 2oo-35o F. [5, 13, 15, 17.] 



Thermometer, Water. A thermometer filled with water instead 

 of mercury. 



Thermometer, Wet and Dry Bulb. See Hygrometer. 



Thermometrograph. See Thermograph. [13, 15, 20, 21.] 



Thermomnltiplier. An instrument for measuiing small varia- 

 tions of temperature due to radiant heat. [21.] 



Thermophone. An instrument in which sonorous vibrations are 

 produced by the expansion of heated bodies connected with 

 an electro-magnet. 



Thermopile. An instrument consisting essentially of a number 

 of thermo-couples (q.v.) in which all the odd junctions are 

 presented together at one end and all the even junctions at 

 the other, so as to yield a thermo-electric current. The 

 electromotive force obtained with a given difference of 

 temperature between the ends of the pile is proportional to 

 the number of junctions. 



Thermo Regulator. See Thermostat. [4.] 



Thermoscope. An instrument for indicating, but not measuring, 

 changes of temperature. [2.] 



Thermostat. A self-acting apparatus for maintaining a constant, 

 or nearly constant, temperature by the unequal expansion 

 of different metals, liquids, or gases by heat. [2, 4, 21, 23, 

 26, 27.] 



