ANNUAL ADDRESS OF THE PRESIDENT. LXXIII 
and in adopting one and one-quarter grains the Committee seem to 
have augmented the weight of the troy pound by about one-quarter 
ofa grain. The corrections which result to the Exchequer troy 
weights upon the Committee’s assumption that the sum of the eight 
and four ounce weights was one and one-quarter grains too light 
are given in the third column of Table I; while the fourth column 
contains the corrections found by Mr. Chisholm in 1873,’ and the 
fifth column shows the loss of weight which occurred between 1758 
and 1873. In view of the fact that these weights were constantly 
used for comparing local standards during a period of no less than 
225 years, from 1588 to 1825, their excellent preservation is very 
remarkable. 
In the report of the Committee of 1758 there is another set of 
comparisons of the Exchequer troy weights;? said comparisons 
having been made on April 14, 1758, in accordance with the di- 
rections of the Committee, by Mr. Freeman and Mr. Reed, expert 
scale makers, in the presence of Mr. Farley, deputy chamberlain, 
They are as follows: 
$-oz. hollow = 4-oz. solid + 4 grain. 
t-oz. weight = All smaller weights — 4 grain. 
3-02. “ pau “c v2.4 4 “ 
[Ca Sy —} * 
9-072. “ poe 6 ae “ 
402, “ = 5 + 0 grains. 
8-02, “ = te ce | a i 
16-oz. se = ss +0 “c 
s2-o7, SS : “ sgh. fiat 
64-02. “e = sc +0 “ 
12007, 08 = ae +15 “ 
256-0z,. “ = - —24 *“ 
In these equations the symbol + 0 is used to indicate the relation 
which the Committee expressed by saying that the weights “very 
nearly agreed.” 
Regarding the entire set of weights as a standard of 512 ounces, 
and putting x for the mass of the 4-oz. solid weight, we have 
$-oz. solid = Ia. 
$-oz. hollow = 12 -+ 3 grain. 
143, p. 21. 711, p. 435. 
