64 FRIDTJOF NANSEN. M.-N. KI. 
been reduced accordingly, and the densities were calculated from the values 
as thus obtained, which give very probable results. | 
During a cruise with the Michael Sars, under Dr. J. Hjort, in 
1900, which Helland-Hansen and the writer joined as oceanographers, 
several Stations (M 16— 47, Pl. V), between Iceland and Jan Mayen 
and east of the latter, were taken in August, 1900 1. The temperatures 
were determined by an insulated water-bottle of the writers construction, 
provided with fixed deep-sea thermometer; temperatures were also 
determined by some specially constructed Negretti and Zambra Re- 
versing Thermometers divided into tenths of degrees Centigrade. The 
thermometer-readings have been carefully corrected, for instrumental 
errors, zero-correction, alterations due to pressure, etc., and may be ac- 
cepted as the most accurate observations hitherto made in these regions. 
The water-samples were to a great extent taken in Soda Water bottles, 
containing 600 cubiccentimetres, and closed with patent india-rubber 
stoppers. The determinations of salinity were made with the Hydro- 
meter of Total Immersion, and by Titration. The determinations, 
especially the former, are very accurate; but the salinities obtained 
by titrations, have a tendency to be somewhat too high, evidently owing 
to some slight evaporation through the cork-stoppers of the glass-bottles 
which were employed to contain the small samples (of 100 ccm.), taken 
for titration. It is probable that Amundsen’s samples have been more 
trustworthy in this respect, as they were greater (150 ccm.) and were more 
carefully closed. His comparatively low values of the amount of Clorine in 
the bottom-water (giving salinities between 3490 and 34'92 0/09) may there- 
fore be considered as more accurate than those of the above titrations. 
The Stations of the various Expeditions have been introduced on 
the chart PI. V, Fig. 1. The observations at these Stations have been 
used for the construction of the maps (Pl. V) showing the horizontal 
Distribution of Temperature, Salinity, and Density in the northern Nor- 
wegian Sea at 0, 50, 100, 200, 300, and 400 metres, chiefly in the 
months between June and August. Besides the Expeditions mentioned 
above, the observations of the following Expeditions have also been 
used for these maps: 
Expedition of the Michael Sars in February and March, 1001 
(between Norway and Bear Island), in April to July 1901 (between 
1 Cf. Helland-Hansen and Nansen, The Physical Oceanography of the Norwegian 
Sea, Report on Norwegian Fishery and Marine Investigations, vol II, No. 2. See also 
F. Nansen, Some Oceanographical Results of the Expedition with the Michael Sars 
1900, Nyt Mag. for Naturvidenskaberne, vol. 39, Christiania, 1901, pp. 129— 161. 
2 
