Oct. 9, 1873] 
liamentary copies Nos. 1 and 2 of the standard pound, 
and two auxiliary platinum weights together, equal to 
about 1432°35 grains. The mean result of 60 compari- 
sons was to find the Kilogramme des Archives epual to 
15432°34813 grains. But Prof. Miller was not satisfied 
with this result, as one of the auxiliary weights was found 
to contain a small cavity filled with some hygroscopic 
substance, which rendered its weight slightly variable. 
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Fic. 12.—Platinum Kilogram &. 
He therefore considered it requisite to make further com- 
parisons directly with the English standard pound. 
For this purpose, a platinum kilogram, constructed by 
Gambey, was procured at Paris by Prof. Miller, and was 
accurately compared by him with the Kilogramme des 
Archives. This platinum kilogram, designated as € by 
Prof. Miller, is similar in form to the prototype, but is a 
little smaller, in consequence of the somewhat greater 
density of the platinum of which it is composed. Its 
Fic. 13.—Gilt Gun-metal Kilogram R. 
density was determined by hydrostatic weighings to be 
21°13791. From the mean of 100 direct comparisons 
with the Kilogramme des Archives, € was found to be 
lighter in a vacuum than the French standard by 1°56 
mgr. (0'02412 gr.). For ascertaining the weight of € in 
terms of the new imperial standard pound, Prof. Miller 
subsequently compared this kilogram with the imperial 
standard pound, together with each of its Parliamentary 
copies successively, and one of four auxiliary platinum 
NATURE 
491 
weights, each of 1432°324 grains, constructed for the 
purpose, and accurately verified in terms of the imperial 
standard, by means of supplementary platinum weights. 
The mean result of 166 direct comparisons of & was to 
find its value = 15432°32462 grains. The Kilogramme 
des Archives was consequently determined to be equal in 
a vacuum to 15432°34874 imperial grains, or 2'20462125 
standard platinum lb. ; and the imperial standard pound 
equal to 453°5926525 metric grammes. These equivalents 
have since been generally accepted, and were legalised in 
this country by the Metric Act, 1864. 
The platinum kilogram € has since been deposited in 
the Standards Department, together with a second kilo- 
gram, of gilt gun metal, also made under Prof. Miller’s 
directions, and intended as a standard for the adjustment 
of commercial metric weights, like the French £7/ogramme 
aiton deposited at the Ministére de l’Intérieure at Paris. 
This gilt gun metal kilogram was constructed by Oertling 
and has been denoted as R by Prof. Miller. Its form is 
spherical with a knob. Its density is 8'3291°. The mean 
result of 24 comparisons with € showed that in a vacuum 
the weight of # was 1°47 mgr. less than &, and 3'04 mgr. 
less than the Kilogramme des Archives. In standard air 
(4 = 18°7 C., d. = 755°64 mm.) # displaced 143'92 mgr. 
and the Kilogramme des Archives 58°36 mgr. was 
then found to be 88°6 mgr. lighter in air than the French 
platinum prototype, and only o'06 mer. lighter than the 
French commercial brass standard kilogram. 
Although the metric system was established in France 
as the legal system of weights and measures in 1799, it 
was not until more stringent provisions of law for enforc- 
ing its exclusive use were passed in 1837, that metric 
weights and measures began to be generally adopted in 
that country. Since that period it has been gradually 
adopted in other countries, and there is now every pros- 
pect of its finally becoming universally in use, and being 
acknowledged as an international system of weights and 
measures, Attention has been already drawn in NATURE, 
vol. vii. p. 197, to the proceedings of the International Metric 
Commission at Paris for the construction of uniform 
metric standards for all countries who have adopted or 
contemplated the adoption of the metric system, as well 
as to the material, an alloy of platinum and iridium, 
adopted for the new standards, and the peculiar form of 
the new International standard metre. It will therefore 
be sufficient here merely to show the adopted form of the 
new standard metres, as compared with that of the exist- 
ing Standard Metre des Archives, in the following figures, 
all of the actual size : 
Fic. 14.—Form of New Standard Metres. 
The form of the new International kilogram will be the 
same as that of the Kilogramme des Archives, a cylinder 
of equal diameter and height, with the edges slightly 
rounded, as already described. 
H. W. CHISHOLM 
(To be continued.) 
NOTES 
A LETTER has been addressed by Dr. Anton Dohrn to the Col- 
leges, and other bodies of the University of Oxford, giving an 
account of the cost, extent, and purposes of his zoological esta- 
blishment at Naples, pointing out the incalculable advantages 
