338 
MR. H. J. CHANEY’S RE-DETERMINATION OF 
determined in a vertical position, by comparison therefore with a standard ther¬ 
mometer. 
Kew No. 430. 
No. 12,765. 
No. 20,065. 
Scale readings. 
Corrections. 
Scale readings. 
Corrections. 
Scale readings. 
Corrections. 
° F. 
° F. 
o p 
° F. 
O Ji 
°F. 
41-5 
+ 0-013 
41-6 
+ 0-121 
41-7 
- o-ooi 
50-2 
+ 0-047 
50-4 
+ 0-045 
50-4 
+ 0-071 
59-0 
+ 0-060 
59-3 
- 0-003 
59-2 
+ 0124 
681 
+ 0-101 
68-5 
- 0-037 
68-4 
+ 0-017 
76'8 
+ 0-013 
77-0 
-f 0-027 
76-9 
+ 0-104 
864 
+ 0-080 
86-4 
+ 0-065 
94-7 
+ 0-130 
95-0 
+ 0-082 
Estimated probable error of correction is 0°’01 Fahr. 
The coefficients of interior pressure at 100° C. for one millimetre of mercury 
is 0-0004334, for No. 430 ; and for the other thermometers the coefficients of pressure 
were stated as :— 
Zero-points :— 
12,765 . 0-0002950 ± 0-0000014. 
20,065 . 0-0002039 ± 0-0000008. 
Kew, 430 . 32°-212 Fahr. 
12,765 . 32°-442 „ 
20,065 . 32°-418 „ 
Weighings. 
Weighings .—For the weighings .three balances were used, by means of which 
differences of y^th, 2 ' boo th, and ryabiffh of a grain might be ascertained respectively ; 
for weighings in water it was possible, however, to weigh only to y-^yth of a grain. 
The weighings were made by Borda’s method of counterpoise, the position of equi¬ 
librium of the beam, and the weight of water displaced by the cylinder being- 
calculated after the methods given by Miller and Broch. 
The gravimeter was suspended in a glass vessel by a platinum wire hook, and 
was surrounded by at least two inches of water, the depth of the water being- 
regulated so that it always rose to the same height in the vessel, whether the 
gravimeter was suspended therein or the wire hook only. The wire hook was 
kept polished, any water found to adhere to its upper surface being either wiped 
off or dried off by a blowpipe before the weighings were taken. 
