102 
MEASUREMENT OF HIGH TEMPERATURES. 
[BULL. 54. 
Taple 10. — Temperature variations of the Latimer-ClarJc standards D, E, F. 
1883. 
t. 
Standard No. E. 
Standard No. F. 
Standard No. I). 
a 
Mean temperature co- 
efficient of D, E, F. 
E. 
Check 
Daniell 
at 20°. 
E. 
Check 
Daniell 
at 20°. 
t. 
E. 

1.424 
1.072 
1.425 
1.072 

1.422 
Between 0° and 40°. 
14 
1. 421 
1.072 
1.420 
1.072 
15 
1.420 
17 
1.420 
1.072 
1.421 
1.072 
29 
1.415 
a= -0.00020. 
21 
1.419 
1.072 
1.419 
1.072 
40 
1.409 
27 
36 
41 
48 
1.417 
1.414 
1.411 
1.407 
1.072 
1.072 
1.072 
1.072 
1.417 
1.414 
1.411 
1.407 
1.072 
1.072 
1.072 
1.072 
^ Later and earlier 

10 
1.425 
1.423 
54 
1.404 
1.072 
1.404 
1.072 
13 
1.421 
60 
1.400 
1.072 
1.400 
1.072 
1887. 

27 
1.439 
1.426 
1.076 
1.075 
1. 439 
1.428 
1.076 
1.074 
Between 0° and 30°. 
a= -0.00023. 
Table 11. — Temperature variations of the siphon Daniell standards. 
1883. 
The electromotive force and temperature coefficient of the Latimer- 
Clark standard lias been much discussed. Besides Clark's 1 original in- 
vestigation, v. Ettinghausen, 2 who cites the relevant researches (Clark, 
Helmholtz, Kittler,lTppenborn, Alder Wright) and Rayleigh 3 have given 
it critical study. My own temperature coefficient is smaller than that 
ordinarily given, and indeed so small as usually to be negligible. The 
'Clark: Jour. Soc. Tel. Engineers, vol. 7, 1878, p. 53. 
2 v. Ettinghausen: Wiener Zeitschr. f. Electrotech., 1884, p. 1. 
3 Rayleigh: Rept. 54th Meeting Brit. Assoc., Adv. Sci., 1884, p. C51 ; Proc. Royal 
Soc, London, vol. 40, 1886, p. 79. 
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