940 PROF. W. H. MILLER ON THE CONSTRUCTION OF THE NEW STANDARD POUND. 
The weights (12800), (6400), (3200), (1600), (800), (400), (200), (100), and a 
weight of 100 grains unmarked, which accompany Barrow’s balance, are of bronze, 
for which log A=0'92260. Let them be denoted by W, V, U, T, S, R, Q, P, O 
respectively. It was found that 
No. of Comp. gr. 
4 
P =0 
-0-0001 
4 
Q=P + 0 
-0-0037 
4 
R =Q+p + 0 
+ 0-0108 
4 
S =R + Q+P + 0 
-0-0009 
4 
T =S + R + Q + P + 0 
-0-0155 
4 
U=T + S + R + Q+P+0 
-0-0207 
4 
V=U+T + S + R + Q+P + 0 
-0-0030 
4 
W=V+U+T+S+R+Q+P+0 
—0-0516 
Hence gr. 
P = 0-0-0001 
Q = 20-0-0038 
R= 40 + 0-0069 
S = 80 + 0-0021 
T= 160-0-0104 
U= 320-0-0260 
V= 640-0-0343 
W=128O-0-1172 
By a mean of 4 comparisons, the bronze weights U+T+S+PH- platinum weights 
(32) + (16)-i-(8) + (4)+0'0133gr.:i!: platinum troy pound T in air (^=10‘45,&=:768’28). 
Hence U+T+S+P=5699'9724 grains. 
U+T4-S-l-P=570— 0*0344 grain. Therefore 570=5700*0068 grains. Hence 
gr. 
(100) = 100-0000 
(200; = 199*9964 
(400) = 400-0074 
(800) = 800-0031 
gr- 
(1600) = 1599-9915 
(3200) = 3199*9778 
(6400) = 6399-9733 
(12800) = 12799*8981 
The values assigned to these weights in computing the densities of some of the old 
troy pounds and secondary standard lbs., were obtained upon the supposition that 
the absolute weight of the platinum troy pound T was about 0*002 grain less than it 
afterwards appeared to be on reducing the observations with the weight of air as 
determined by Regnault. The error, which was not discovered till after going to 
press, is much too small to affect the last figure of the calculated densities. 
Probable Errors of the Platinum Weights. 
Probable errors of the comparisons of T, and of the auxiliary weights. 
Page. 
Weights compared. 
No. of comparisons (n). 
Probable error of one comparison. 
Probable error of n comparisons. 
168 
gr- 
gr. 
815 
T, Sp 
0-000982 
0-000076 
818 
T, RS 
78 
0-000727 
„ 0-000083 
824 
T, A + B + C + D + F 
40 
0-000540 
0-000086 
825 
A, F+G 
22 
0-000287 
0-000061 
825 
B, F + G 
22 
0-000560 
0-000123 
826 
C, F+G 
22 
0-000521 
0-000114 
826 
D, F + G 
22 
0-000669 
0-000146 
826 
F, G+H 
31 
0-000458 
0-000084 
821 
G, H + K 
10 
0-000170 
0-000057 
821 
G, H + L 
10 
0-000154 
0-000051 
