LX PHILOSOPHICAL SOCIETY OF WASHINGTON. 
The metric standard of weight, called a kilogram, was constructed 
under the direction of the French Academy of Sciences simulta- 
neously with the meter; the work being done principally by Lefévre- 
Gineau and Borda. It was intended that the kilogram should have 
the same mass as a cubic decimeter of pure water at maximum 
density, and the experimental determination of that mass was made 
by finding the difference of weight in air and in water of a hollow 
brass cylinder whose exterior dimensions at a temperature of 17°6° 
C. were, height = 2'437672 decimeters, diameter = 2°428568 deci- 
meters, volume = 11°2900054 cubic decimeters. The difference of 
weight in question was first measured in terms of certain brass 
weights, by the aid of which the platinum kilogram of the archives 
was subsequently constructed, special care being taken to apply the 
corrections necessary to reduce all the weighings to what they 
would have been if made in a vacuum.’ 
The best results hitherto obtained for the weight of a cubic deci- 
meter of water, expressed in terms of the kilogram of the archives, 
are as follows :? 
Weight of 
a cubic 
Date. Country. Observer. decimeter 
of water | 
at 4° C. 
Grams. 
1795 ....-| France_._-- Leféyre-Ginea- 24. 2 soe 1000-000 
797 _- 
England ---| Shuckburgh and Kater __--_-_____-__- 1000-480 
1821_- 
1825____] Sweden -__-| Berzelius, Svanberg, and Akermann-_-_-| 1000-296 
1880.-22)), Austria's, 5) Siampien. 220562 ce eel ee 999-653 
184ic.2*| Russia's ON Koper ee Seo ie eee 999-989 
AMean_\. oY OU 1000-084 
1 Base du Systéme Métrique, T. 8, pp. 574-5. 
2 This table has been deduced from the data given by Prof, Miller in 40, 
p- 760. 
