332 PETTERSSON, SIBERIAN SEA. 



between I.0280 and I.0150 this was tolerably easy, because the 

 areoraeter was at my disposal, but for the numbers of lower 

 spec. weight, the case looked somewhat doubtful, as the instru- 

 ment had been löst during the voyage. 



From the collection of the Vega I selected 3 hermetically 

 sealed water-samples, the specific weight of which had been 

 tested during the expedition with the areometers. By means 

 of the Sprengel pycnometer I ascertained their spec. gravity 



at qr^H C. 



.Spee. gr. Spec. gravity 



Date. Depth. Temp. (areonieter). (Sprengel pycn.). Diff. 



1878 6&7Sept. 12 M. — 1°.3 C I.0238 I.02440 at q:^o C O.oooeo 

 1878 25 Aug. 14 •> + 2°.3 C l.oue l.ous? » » » O.00027 

 1878 26 Aug. 5 .> + 1°.5 C I.0104 I.01040 » » > 0. 



I next proceeded to the examination of the areometer. I 

 prepared 2 samples of salt-water by diluting sea-water from 

 Beeren Island of 1. 02829 sp. gr. with distilled water. The third 

 sample is a solution of NaCl in water used by Mr. Ad er man 



as standard by the determinations of the point l.oiso at , ^_^o C 

 on bis areometers. The spec. weight of the solutions was 

 ascertained on the same occasion with the Sprengel pycno- 

 meter at xxo C. The result of the comparison Avas 



The corrections, which can be deduced from both series 

 of experiments, agree tolerably well. In order to supply the 

 numbers still wanting, I made some determinations with the 

 standard areometer of Mr. A der man, which had ser ved as 

 controlling instrument in the fabrication of the Vega areo- 

 meters, thereby assisted by Mr. Aderman himself. The fol- 

 lowing table of corrections is constructed by means of these 

 experiments. 



In order to obtain the true speciiic weights at x^o C from 

 the areometric determinations registered in the Vega journal, 

 I have added 



