[ad. mod.L. thermoscopium (Bianconi, 1617): see THERMO- and -SCOPE. Cf. F. thermoscope.] An instrument for indicating changes of temperature, of which there are various forms.
a. An early name for the thermometer, esp. in its earlier forms. b. Count Rumford’s name for a differential thermometer for detecting minute differences of temperature. c. An electric or magnetic apparatus, as a thermopile, for detecting and measuring minute differences of temperature. d. Any substance or device used to indicate excessive heat in machinery, variations of bodily temperature, rate of radiation of heat, or the like.
a. [1617. Gius. Bianconi, Sphæra Mundi, seu Cosmographia Demonstrativa.… Thermoscopium.]
1656. trans. Hobbes’s Elem. Philos. (1839), 531. This organ is called a thermometer or thermoscope, because the degrees of heat and cold are measured and marked by it.
1672. Boyle, in Phil. Trans., VII. 5110. The Air by the seal’d Thermoscope appeared hot for the season.
1778. Phil. Trans., LXVIII. 484. The first inventors … called … their instruments … Baroscopes, Thermoscopes, Microscopes.
1790. De Luc, ibid., LXXXI. 32. The thermoscopes of quicksilver and water.
1842. Brande, Dict. Sc., etc. s.v. Thermometer, The thermometer of Drebbel and Sanctorio … had no scale, and was therefore merely an indicator of changes of temperature, or a thermoscope.
b. 1804. Ct. Rumford, in Phil. Trans., XCIV. 101. An instrument I contrived for measuring, or rather for discovering, those very small changes of temperature in bodies, which are occasioned by the radiations of other neighbouring bodies, which happen to be at a higher, or at a lower temperature. This instrument … I shall take the liberty to call a thermoscope.
1842. Brande, Dict. Sc., etc. s.v. The modification of the air thermometer, called by Leslie a differential thermometer, was claimed by Count Rumford as one of his own inventions, under the name of thermoscope.
1850. Grove, Corr. Phys. Forces (ed. 2), 42. With the most delicate thermoscope, he could detect no indications of transmitted heat.
1860. Mayne, Expos. Lex., Thermoscopium, term for an instrument by Rumford for measuring the difference of temperature by dilatation of dry air contained in two balls, which a long tube, twice bent, separates from each other: a thermoscope.
c. 1835. [see THERMO-MULTIPLIER].
1879. trans. Du Moncel’s Telephone, 195. It is therefore a microphone as well as a thermoscope.
1881. Nature, 17 Feb., 372/2. The magnetic thermoscope is intended to indicate differences of temperature by showing differences between the magnetic moments of steel magnets.
d. 1877. Knight, Dict. Mech, 2550/1. Barker and Mayer’s thermoscope … is designed to indicate … the existence of excessive heat in journal-bearings…. Marcy’s thermoscope … is particularly designed for experiments on animal heat. Ibid. (1884), Suppl. 892/2. The varied changes of tint … may serve … as a rough index of the temperature of surrounding bodies, thus constituting the little instrument a thermoscope.
