THE electrical resistance thermometer is now widely recognized as one of the most available and best of the many devices that may be employed as an accurate secondary standard for the measurement of temperature, and methods for its easy manufacture are greatly to be desired.
The present ultimate standard scale of temperature is Lord Kelvin's so-called thermodynamic scale, or the almost identical scale of the constant volume hydrogen thermometer. It is well understood that other scales, such as one obtained from the expansion of mercury-ln-glass, or from the temperature variation in resistance of some metal, or from the potential change in some thermo-junction, or from any other temperature effect, all differ from each other and from the standard scale. Whenever, therefore, any one of the secondary thermometers is employed, its readings must generally be reduced to the gas scale of temperature by some more or less elaborate conversion tables or sets of corrections. The question of the interrelation of different thermometric scales is a very extensive one, and we point out here simply the essential fact that they are all different.
NOT~.--The F1 anklin hmtitute is not responsible for the statements and opinionk advanced by contr butors to the JOURNAL]
Copyr~ht :0H byTHsPRA~KLI~ I~STI~T~.