thermographn.

1840 J. F. W. Herschel in Philos. Trans. (Royal Soc.) 130 51 I have discovered a process by which the calorific rays in the solar spectrum are made to leave their impress on a surface properly prepared for the purpose, so as to form what may be called a thermograph of the spectrum.

1865 Reader 28 Jan. 105/2 His drying paper presented to him a thermograph of the spectrum, and showed the heating power to extend far beyond the red.

1871 J. Tyndall Fragm. Sci. (1879) I. ii. 48 The light is cut away,..but an invisible thermograph remains.

1906 Athenæum 23 June 768/3 Such experiments..will yield valuable ‘thermographs’, as the resulting parti-coloured ‘prints’ are named.

1843 Mechanics' Mag. 39 128 Obtained..by the aid of the pyrometer,..with the addition of the thermograph, or heat-register, which I have added to it.

1879 T. Bryant Man. Pract. Surg. (ed. 3) I. i. 55 These points are well seen in the following thermographs.

1881 Nature 15 Sept. 470/2 Bowkett's New Thermograph,..an instrument for recording changes of temperature, which are measured by the action of heat upon a hollow circular metallic ring connected with a circular vessel.

1883–4 Med. Ann. 78 Thermograph—an ingenious instrument..for recording in permanent diagrams all variations in temperature occurring in any patient.