IMPERIAL STANDARD TROY POUND WEIGHT. 
473 
These weighings give (using the same elements of reduction as before, giving to 
b and t the signification already explained, and taking the means according to the 
number of observations,) as follow : 
1829. 
No. of 
Comp. 
Comparisons. 
b. 
t. 
1829. 
No. of 
Comp. 
Comparisons. 
b. 
t. 
July 2. 
20 
RS = U -0-01036 
29-368 
65-65 
July 16. 
20 
RS = U -0 ; 00476 
29-839 
67-32 
14. 
14 
RS = U - 0-00142 
29-777 
67-03 
Aug. 2. 
30 
RS = U + 0-00437 
30-186 
64-59 
15. 
16 
RS = U - 0-00352 
29-871 
67-62 
4. 
40 
RS = U - 0-00099 
29-709 
64-61 
gr- 
b. 
t. 
Mean of 140 
RS = U 
- 0-00205 
29-806 65°-73 
The first four days Robinson’s balance is used ; the last two, Ramsden’s balance. 
18. The last pound which Captain Nehus compared with the now lost imperial 
standard troy pound, was that of the Royal Mint. It is marked “ T^ P d 1824”, and the 
same that Captain Kater designates by No. 3.* Mr. (afterwards Sir John) Barton, 
of the Royal Mint, had the kindness to bring it to Somerset House, and it was there 
compared in his presence. The pound appeared in high preservation, and bore no 
marks of any oxydation whatever. It is needless to repeat that the same barometer 
and thermometers were used. The balance was that of Robinson. I designate this 
pound by the mark RM, since it belongs to the Royal Mint. 
No. 
Comparisons. 
Barom. 
Attached 
Therm. 
Therm. L. 
Therm. R. 
No. 
Comparisons. 
Barom. 
Attached 
Therm. 
Therm. L. 
Therm. R. 
pt. 
pt- gr - 
1. 
RM = U + 0-20 
65-8 
66-1 
9. 
RM = U+0-90 
2. 
RM — U + 0-65 
10. 
RM-U+1-20 
66-5 
66-8 
3. 
RM = U + 0-75 
11. 
RM=U ‘ 0-00+0-01 
4. 
RM = U + 0-60 
12. 
RM = U— 0-30+0-01 
5. 
RM=U + 1-10 
13. 
RM= U+0-45+0-01 
6. 
RM = U + 0-55 
14. 
RM = U+0-20+0-01 
7. 
RM = U + 1-30 
15. 
RM = U— 0-05+0-01 
8. 
RM = U + 0-20 
16. 
RM= U+0-20+0-01 
29-776 
65-0 
66-2 
66-8 
Pt. 
gr. Barom 
Att. Th. 
Th. JL. 
Th. K. 
1829, July 30. Mean of 16 RM - U + 0-496875 + 0-00375 29-776 65°-0 
65°-17 
66°-57 
This gives, reduced for the mean of 16 comparisons, 
RM = U + 0-00887 29-679 65° : 91 
Captain Kater found in 1824 ~j~, RM = U + 0-0021 gr. The difference is 0-0068 gr. 
19. I shall now put all the results obtained by Captain Nehus in London in one view. 
No. of 
Comp. 
Comparisons. 
b. 
, 
92 
300 
60 
140 
16 
K = U + 0-03389 
S.p = U - 0-00857 
S. b = U — 0-01034 
RS = U — 0-00205 
RM = U + 0-00887 
29646 
29722 
29-965 
29-806 
29679 
65-09 
65-62 
64- 50 
65- 73 
65-91 
* Philosophical Transactions, 1826, p. 12. 17, 18. 
3 p 
f Ibid., p. 18. 
MDCCCXXXVI. 
