THE MASS OF A CUBIC INCH OF DISTILLED WATER. 
337 
Coefficient of pressure (or pressure on reservoir) for one millimetre of mercury, as 
applied when thermometer was used in a vertical position is 0-0001025. 
Boiling-point in a horizontal position is 100 o, 0242 dr O'OOOOl 1. The value of a 
division in “normal” degrees being 0°*999758 dz0°'00001I. 
Error of zero-point, when the thermometer was placed in a horizontal position, 
was 0°‘074 C. 
Thermometer No. 4518, is a Centigrade thermometer of similar form to 4517. 
Boiling-point in a horizontal position is 100 o, 0665. The value of a division being 
0°-999335 ± 0-000017. 
Zero-point; horizontal position, — 0 o- 087. 
Thermometer No. 4575.—Divided into 0 o, L C. from — 4°'l to 55°T. Distance from 
middle of reservoir to 0° C. is 64 mm. Total length of thermometer, 
482 mm. Divisions not equidistant, but by comparison with a standard 
thermometer the following corrections were obtained :— 
Scale. 
Corrections. 
O 
O 
5-1 
+ 0-014 
10-7 
+ 0-007 
152 
+ 0011 
20-2 
- 0-006 
24-9 
- 0-024 
30T 
- 0-045 
35-0 
- 0-051 
Coefficient of pressure is 0-0002264. 
Zero-point; horizontal position, -f 0 o, 314. 
Thermometer ; Kew, 430.—Divided into 1° Fahr. from — 10° to + 217° Fahr. Nos. 
12,765 and 20,065. Divided into tenths of a degree from 20° to 84° Fahr. 
430. 
12,765. 
20,065. 
mm. 
mm. 
mm. 
Distance in millimetres from middle of tlie reservoir to 32° Fahr. . 
228-3 
134 
80-3 
Length of a degree. 
1-908 
2-75 
4-27 
Total length of the thermometer. 
620 
161 
333 
It was found that the construction of the above thermometers, Kew, 12,765, and 
20,065, did not permit of exact calibration, and the following corrections were 
MPCCCXCII.—A, 2 X 
