468 
PROFESSOR SCHUMACHER ON THE LATE 
in volume for 1° of Fahrenheit (= 0-0001001), and s the expansion of the brass 
scale in length for 1° of Fahrenheit (= OOOOO 10434). The temperature of the brass 
scale and of the mercury is supposed to be the same. 
13. After having - stated all the elements necessary for the reduction of the obser- 
vations before given, I may now give them reduced in a general synopsis. 
With Ramsden’s Balance. 
No. of 
Comp. 
Comparisons. 
b. 
t. 
No. of 
Comp. 
Comparisons. 
b. 
t. 
1829. 
gr. 
1829. 
gr. 
June 21. 
8 
S.p = U - 0-00811 
29-683 
67-07 
June 29. 
10 
S.p = U - 0-00927 
29-630 
66-34 
23. 
16 
S.P = U - 0-00764 
29-832 
66-90 
July 1. 
10 
S.p = U - 0-01459 
29-498 
65-84 
24. 
16 
S.p = U - 0-00637 
29-922 
67-22 
4. 
10 
S.p = U - 0-00930 
29-507 
65-01 
24. 
10 
S.P = U - 0-00652 
29-964 
67-32 
5. 
10 
S.p = U - 0-01229 
29-495 
64-12 
28. 
10 
S.p = U - 0-01311 
29-328 
68-51 
gr- 
b. 
t. 
Mean of 100 ...... 
s.p = U - 
- 0-00940 
29-677 66°-54 
With Robinson’s Balance. 
June 28. 
10 
S.P = U - 0-01882 
29-413 
69-10 
July 9. 
30 
S.P = U - 0-00918 
29-681 
65-12 
29. 
10 
S.p = U - 0-00882 
29-607 
66-14 
Aug. 1. 
20 
S.P = U + 0-00044 
30-141 
64-07 
July 1. 
10 
S.p = U - 0-02180 
29-392 
6604 
2. 
20 
S.p = U - 0-00281 
30-146 
65-35 
4. 
20 
S.p = U - 0-01458 
29-481 
64-67 
3. 
30 
S. p = U — 0-00473 
29-910 
65-09 
5. 
20 
S.P = U - 0-01119 
29-560 
64-57 
4. 
30 
S.P = U - 0-00518 
29-686 
64-64 
gr. 
b. 
t. 
Mean of 200 ...... 
s.p = U 
- 0-00815 
29-745 65°-16 
The means are taken according to the number of the comparisons of each day =* ; 
I) is the absolute height of the barometer reduced to 32°, and t is the temperature of 
the air and weights as given by the Thermometer R ; its indications being corrected 
by the Table before given (11.). 
The general mean of all the 300 comparisons made (those made by Robinson's 
balance having double weight because they are double in number of those made by 
Ramsden’s balance) is 
S.p = U - 0-00857 gr. b = 29*722, t = 65°-62. 
14. At the same time that Captain Nehus compared my platina copy S.p with the 
imperial standard, he compared also the first brass copy (K.) sent by Captain Kater 
(and compared, as before stated, several times by him with his two copies,) with the 
imperial standard. I begin by giving these observations as they were made, and 
shall afterwards reduce them in the same manner as the comparisons of the platina 
pound. 
The same balances, the same barometer, and the same thermometers were used ; as 
indeed they were at all the weighings made in Somerset House. 
* If the mean result of several days be R, R\ R", . . . ., and the corresponding numbers of comparisons made 
R n + R/ + R" „« + 
on each day n, n', n", . . . . , the mean of all the results is = 
n + n' + n u + 
