ON THE THERMO-ELECTRIC MEASUREMENT OF HIGH 
TEMPERATURES. 
By C^rl Bartjs. 
INTRODUCTION. 
GENERAL ACCOUNT OF METHODS OF PYROMETRY. 
Earlier digests.— Some account of the literature of high temperatures, 
and particularly of the masterly labors of Messrs. Deville ami Troost, 
being essential here, it was deemed expedient to give a brief but fairly 
full digest of all the methods devised and applied for high temperature 
measurement. To do this I made the customary use of the Fortschritte 
der Physik and of the Beiblatter of the Annaleu der Physik, though 
in nearly all cases I have gone back to the original authors. Much as- 
sistance was received from earlier summaries, those of Pelouze, 1 Bec- 
querel, 2 Weinhold, 3 Fischer, 4 Sir William Thomson, 5 Nichjols, 6 Browne, 7 
Lauth, 8 and Shaw, 9 all more or less complete and written with widely 
different ends in view. I must also refer to the reports (1881 and 1884) 
of the committee appointed by the British Association for the Advance- 
ment of Science to investigate the state of our knowledge of spectrum 
analysis. 
I shall try to submit a tolerably full summary of what has been done, 
in most cases, however, giving no more than mere mention of the work 
of the individual observers. Nor shall I make many critical statements, 
for the cardinal difficulties surrounding divers processes described for 
1 Pelonze : Traits complete des Pyrometres ; Paris, 1829. 
2 Becquerel: Recberches snr la determination des hautes temperatures, etc. ; Ann. 
eh. et phys., vol. 68, 1863, p. 49. 
3 Weinhold : Pyrometrische Untersuchungeh ; Pogg. Ann., vol. 149, 1873, p. 186. 
4 Fischer: Ueber Thermometer und Pyrometer; Dingler's Jour., vol. 225, 1877, pp. 
272, 463. 
5 Thomson : Heat, § 10; Encyclopaedia Brit., 9th ed., vol. 11, 1880, p. :^X. 
c Nichols: Am. Jour. Sci., 3d series, vol. 22, 1881, p 363. 
7 Browne: Pyrometers; Nature, vol. 30, 1884, p. 366. 
8 Lauth: Mesures pyrometriques a hautes temperatures; Bull. Soc. Ch., Paris, new 
series, vol. 46, 1886, p. 786. 
9 Shaw: Pyrometer; Encycl. Brit., 9th ed., vol. 20, 1886, p. 129. 
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