328 PETTERSSON, SIBEKIAN SEA. 



tions commenced again on July 24*'', 1879, at Port Clarence 

 and was continued diiring the criiise of the Vega in the 

 Behring Sea until August 7"^''. 



The available material for scientitic investigation con- 

 sisted of: 



1). A complete series of observations regarding the tem- 

 perature and specific gravity of sea-water from different depths. 



2). Annotations concerning the percentage of chlorine in 

 samples of water and ice found by titration on board the ship. 

 As far as regards the samples of ice water these titrations are 

 recorded in chapter 5 of the preceding paper. According to 

 the annotations these determinations seem to have been 

 executed by Nordenskiöld, Palander, Almqvist and 

 other members of the expedition. 



3). A collection of about 30 Avater-samples ^ sealed up 

 in fläsks of 250 cc. each. Among these I found 4 specimens 

 of melted rossol and of very concentrated brines collected on 

 cold winter days from the surface of ice-floes. 



4) The thermometer (Äderman) and one of the areometers 

 (also by Aderrnan) employed in the hydrographic measure- 

 ments (for waters of the spec. gravity from I.0290 to l.oiso). 



It must be obvious to the reader that our discussion of 

 the hydrographic conformation of the Siberian sea must be 

 based principally on the observations 1). In order to calculate 

 the percentage of salt in the waters from their spec. gravity 

 the latter must be referred to one common standard of tem- 

 perature. 



The advantage of choosing the point of 0° C for this pur- 

 pose is so great, that I dåre say, that every calculus based 

 upon an other principle, instead of simplifying the matter^ 

 would prove to be an unnecessary complication. 



In the sixth column of the following tables I, II, III & IV 

 the temperatures of the water-samples in situ are recorded. We 

 may see from this, that zero is the natural point of comparison, 

 aye, almost the arithmetical mean of these numbers, the greater 

 part of the temperatures being situated a few degrees above 

 or below 0° C. The only exception is due to the warm water 

 of sliglit specific iveigJit from the surface, especially in the vici- 

 nity of the rivers. A few metres lower the usual temperature 

 of the water, from — 2° to + 1° or + 2° C, prevails almost 



^ The original number, which was far greater, was reduced to this, 

 every fläsk being rejected, W'hich was not autlientically signed or hermetic- 

 ally closed. 



