332 
MR, H J. CHANEY’S RE-DETERMINATION OF 
Then the equivalent value of the cubic decimetre, as deduced 
from the Shuckburgh and Kater value of the cubic inch, 
would be. 1000'480 grms. 
Other investigations have given :— 
(1825) Berzelius ' 
Svanberg > . . . . 
Akermann^ 
(1834) Stampfer. 
(1841) Kupffer. 
1000-296 
999-653 
999-989 
The arithmetical mean of these five results is 1000 - 084 grms., and there is a 
difference of 0"827 grm. between the highest and lowest result. The difference between 
the results appears to arise mainly from inaccuracy in the measurement of tem¬ 
perature, and uncertainty as to the condition of the water used. 
Dr. Broch* revised a report by Tralles on Lefevre-Gtneau’s original work, and 
arrived at the conclusion that probably the true mass of a cubic decimetre of distilled 
water at its maximum density, and in a vacuum, is from 90 to 120 mgrms. less than 
1000 grms. 
Methods and Instruments. 
It has been the object of the present investigation to ascertain the weight of water 
displaced by a body or gravimeter, whose masses, in air and in vacuo, and linear 
dimensions, had been carefully ascertained, rather than to determine the theoretical 
mass of a cubic inch of water. It has been considered that the mass of a definite 
volume of distilled water cannot well be ascertained by weighing the water contained 
in a vessel of a given capacity ; or by the use of gravimeters, made only of one 
material (as brass), and of one particular form (as a sphere). Three gravimeters (or 
hydrometers) therefore, of the following forms were now adopted :— 
Two gravimeters, C and Q, of cylindrical form, one hollow and the other solid, the 
third gravimeter S being hollow, and of spherical form. The hollow gun-metal 
circular cylinder C (fig. 1, page 340) was nearly nine inches in height and diameter, and 
was adopted as being a body the weight and dimensions of which might give the least 
probable error in the several operations of weighing in air and in water. The gravi¬ 
meter C was protected form oxidation by platinising, it having been first made air¬ 
tight. For the purpose of linear measurement, there were traced on the gravimeter 
a series of lines, as indicated in fig. 1. These lines were cut rather deeper than was 
desirable, but the space taken up by them on the surface of the cylinder has been 
considered. 
* ‘ Prcces-Verbaux—Commission Internationale du Metre. Reunions des Membres Franyais. 1873.’ 
