ANNUAL ADDRESS OF THE PRESIDENT. LIX 
To the first of these expressions double weight was assigned, be- 
couse the comparisons of T and U with Sp were about twice as 
numerous as those with RS. The resulting mean was therefore 
 T=U — 052857 grains = 575947148 grains, 
and from that value of T the new standard avoirdupois pound of 
7000 grains was constructed. 
From some time in the fifteenth century until the adoption of the 
metric system in August, 1793, the system of weights employed in 
France was the poids de mare, having for its ultimate standard the 
pile de Charlemagne, which was then kept in the Mint, and is now 
deposited in the Conservatoire des Arts et Métiers. The table of 
this weight was 
72 grains = 1 gros = 72 grains. 
8 gros =lonce= 576 “ 
8 onces = 1 marc= 4608 “ 
2 mares = 1 livre= 9216 < 
The origin of the pile de Charlemagne is not certainly known, 
but it is thought to have been made by direction of King John (A. 
D. 1350-1364). It consists of a set of brass cup-weights, fitting 
one within the other, and the whole weighing fifty marcs. The 
nominal and actual weights of the several pieces are as follows:* 
Mares. Grains. 
Boite de 20 mares . 20 + 1:4 
Piécede1l4 “ . 144 45 
de 8 “* 8 — 04 
dani a ie mee Ot], 
PN eines x) esos 120 
rege a ot Bite) OF 
Marc divisé yh: ey ( 
50” =,7.0°0 
In determining the relation of the poids de mare to the metric 
weights, the committee for the construction of the kilogram regarded 
the entire pile de Charlemagne as a standard of fifty marcs, and 
considered the individual pieces as subject to the corrections stated. 
On that basis they found 
1 kilogram = 18827:15 French grains? 
and as a kilogram is equal to 15432'34874° English troy grains, we 
have 
1 livre, poids de mare = 7554°22 troy grains. 
= 489°506 grams. 
417, pp. 270-71. 7 Base du Systéme Métrique. T. 3, p. 638. 340, p. 898. 
