458 
PROFESSOR SCHUMACHER ON THE LATE 
Date. 
Unmarked Pound. 
Prof, S.’s Pound. 
June 13. 
33 
3-3 
4-6 
35 
4-8 
3-8 
4-0 
3-6 
Mean . . . 
4-17 
3-55 
3-00 
3-17 
7-17 
0-38 
Deduct. . 
4-00 
3-17 
N.B. TJ2 gr. was placed in the opposite scale when the 
unmarked pound was counterpoised, and removed on replacing 
that pound with Prof. Schumacher’s pound. 
The unmarked pound is heavier than the imperial pound 
"0267 gr., or 4 - 0 divisions. 
Prof. S.’s pound too heavy 0‘38 div. = ’0025 gr. 
“ Henry Kater.” 
The divisions to be deducted from the unmarked pound are, after an accurate cal- 
culation, 4 - 005 = 4’01. Of course Robinson’s copy is, after the comparisons with the 
unmarked pound, too heavy 0*39 div. = 0’0026 gr., and by a mean of both pounds it 
is too heavy 0’0025 gr. 
I call this new or second pound, made by Robinson, K n , in order to distinguish it 
from the first pound, made by Bate, and compared for me by Captain Kater, which 
I have called K. 
3. As soon as I received K n , (Sept. 6, 1828,) I proceeded to compare it with K, and 
obtained the following comparisons, in which the divisions are already reduced to 
parts of the grain. 
1828. 
gr. 
1828. 
g r - 
Sept. 7. 
K = K n 4- 0-0191 
Sept. 21. 
K = K n + 0-0192 
4- 0-0204 
4- 0-0209 
4- 0-0207 
Sept. 22. 
4- 0-0200 
+ 0-0182 
4- 0-0216 
4- 0-0187 
4- 0-0199 
Sept. 21. 
4- 0-0209 
4- 0-0196 
4- 0-0193 
+ 0-0207 
4- 0-0185 
4- 0-0196 
4- 0-0188 
4- 0 0216 
4- 0-0198 
4- 0-0193 
Mean of the three days K=K n 4-00198 gr. (20 comparisons.) 
4. This would give, assuming as zero Captain Rater’s determination of K n , (which 
he found too heavy 0 0025 gr.,) K too heavy 0’0223 gr. Therefore K, which, accord- 
ing to Captain Rater’s first statement, should not exceed the standard more than 
0’006 gr., exceeded it 0’022 gr. This discordance being far too considerable for the 
powers of Robinson’s balances, and not suggesting such a difference of specific gra- 
vity between the two kinds of brass (Bate’s and Robinson’s) that might explain it, I 
sent R back to Captain Rater, with a request that he would compare it once more 
with his two pounds ; explaining at the same time the cause of the additional trouble 
