AND RATIO OF THEIR ATOMIC WKKJHTS. 1 1 



which were filled with ineivuiy l)y l)oiliug in a vacuiiin. These wei'e transferred 

 fi'oni ice to steam, and tlie expansion calculated from the amount of mercury ex- 

 pelled at the latter temperature. The height of the harometer during the exposure 

 to steam, corrected for the force of gravity at my laboratory, was 744.1 m.illimetres. 

 Hence the temperature of the steam, according to tlie table by Broch,* was 9!).41". 

 The observations were as follows: 



Tube, full at 9941' 410.22 gr. 308.56 gr. 433-53 gy- 



Weight of tube eniptv 4>-03 " 28.34 " 28.40 



Mercury 369-19 " 280.22 ^" 405- '3 



Mercury expelled on heating. . . 5.6759 " 4-3iSi " 6.2197 



If we assume for the density of mercury 



At 0°, Log. 1.133 3SS8, at 99.41°, Log. 1. 1 25 5573, the cubic expansion of the glas.s between 



0° and 99.41° is found 



A .C02 780 



B .002 755 



C .002 801 



Mean, .002 78 



Hence the expansion for one degree is .000 0280 f 



7. — SOLID CONTENTS OF GLOBES. 



Each globe was weighed in the air while open, and the apparent weight cor- 

 rected for the weight of the air displaced by the glass and by the weights. It was 

 then immersed in water, filled, and weighed, using the same cylinder and the same 

 thermometers as in the previous hydrostatic weighings. The solid contents of the 

 o;lobes wei'e then computed with tlie values of the expansions of water and glass 

 just mentioned. As an example of the process, the determination of the solid 

 contents of globe No. 1 is given. 



Globe I, open 1014.724 gr. 



Reduction to vacuum + -39 ^^ 



True weight 1015.11 ^^ 



Globe I, in water, at 16.58° 572-42 ^^ 



Reduction to vacuum ~ -°8 ^^ 



True weight in water 572-34 ^^ 



Loss in water 442-7 7 



Loss multiplied by i.ooi 123, solid contents. .. .•. 443-27 ^c. 



Reduction to 0° ~ '"° << 



Solid contents at 0° 443 °7 



8. CAPACITY OF GLOBES. 



If now we subtract the solid contents of each globe from the volume we shall 

 have its capacity. For instance, we have 



* Trtwaiix ct Mcmoircs Jii Bureau Intcnialiona/, 1 A, 46. 



t The glass was the ordinary soft German glass, obtained from C. Gerhardt, Marquart's Lager 

 Chemischen LUensilien, Bonn. 



