213 



flie large lioad of tlio lai-ji;e pressure balance in the neiglibonrliood 

 of 1200 atnis. Instead of llie theoretical juinierical ratio 4, three 

 measurements gave resp. ihe valnes 4,012, 4,015, 4,016. average 

 4,014. The weights when the large head is used, must therefore be 

 midtiplied bv this \alne. 



The thus obtained valne for Ihe pressure in the head must uow 

 still be corrected for the excess of piessure of one atmosphere, and 

 for the hydroslatic pressnre difference between the head of the 

 pressure balance and the measnriug tnbe on account ofthemercnrj 

 and oil columns. These liquid columns were ronghly measnred, in 

 which 1 cm. of mercnry more or less need not be considered : nor 

 need the oscillations of the barometer l)e taken into account. 



Finally the thus obtained pressin-e had to be reduced to atmospheres 

 of 1,0336 kg. per cm^ 



In table I. 



The colnmn under r,, indicates the weigiied \olume in gr. of mercury. 



pk-f, the number of kg. on the pressure balauce. 



,, ,, ,, pr the pressure, cori-ected for hydrostatic pressure 



difference in kg. per cm^ 

 ,, ,, ,, p the corrected pressnre in atmospheres. 



,, ,, ,, ,i the ratio of the volnme at 1 atm. and at the 



measured pressure in consequence of the com- 

 pressibility of the glass. 

 ,, ;, „ i^i\, the product of ^ and ?;,, . 



J, ,, ,, V the corrected volume in cm'. 



,, ,, ,, pv the product of /; and c. 



TABLE I. 

 5 6 November 1912. 



vg 



Pk, 



t^''^ 



V 



Pr 



67.1216 4.95473 



55.0346 ! 4.06250 



45.4663 3.35620 



37.3400 ' 2.75633 



31.0636 I 2.29302 



27.3756 

 22.6923 

 19.2695 



2.02087 



1.67508 

 1.42242 



933.57 

 960.26 

 994.18 

 1039.49 

 1096.26 

 1146.91 

 1246.42 

 1365.48 



15 



Proceedings Royal Acad. Amsterdam. Vol. XYII. 



