I906. No. 3- AMUNDSEN’S OCEANOGRAPHIC OBSERVATIONS IN 1901. if 
correction was: + 0'0 in March (Christiania), on July 1, and on Sep- 
tember 5, 1901. 
This instrument was generally used for the surface-temperatures. 
Three meteorological thermometers, Nos. 0, 35 and 39, were also occasio- 
nally used for the sea-surface. The corrections of these instruments were 
also insignificant. 
The Amundsen Water-Bottle. 
This instrument was constructed by Amundsen for taking water- 
samples and temperatures from the upper water-strata, while the vessel 
was under sail. It was a glass-bottle with fairly wide opening and was 
closed by a lid made of brass plate with a sheet of india rubber on its 
underside; the lid was pressed down by a strong spiral spring. The glass 
bottle was protected outside by a hempen network, and it had a heavy 
lead attached underneath. When the bottle was thrown out the line was 
kept quite slack while the bottle was sinking; when it had sunk to the 
desired depth, a sudden pull in the line opened the lid, the bottle was 
filled and hauled up. - The temperature was then at once taken by an 
inserted thermometer, and a water-sample stored. Is does not, however, 
seem probable that the lid has been able to close so perfectly tight as to 
prevent water from being pressed in during the sinking of the bottle, and the 
temperatures and samples obtained in this manner from the water-strata 
down to 15, and sometimes even 25 metres, cannot therefore be con- 
sidered as perfectly trustworthy. They are, however, of value, in as much 
as they at any rate give some information as to the conditions of the water- 
strata underlying the surface-layer, which is of special importance in the 
arctic seas, where ice is melting on the surface. 
On cold days when the sea-water was cooled to its freezing-point (or 
even perhaps slightly supercooled) near the sea-surface, the water-samples 
taken by this small water-bottle, have evidently given erroneous results. 
It is seen in Table I, that on April 30, on May 3—May 9, and May 23 
—May 28 most samples taken from 5 and ro metres or deeper, give 
remarkably high salinities, some even above 36 %00. The explanation 
obviously is that as soon as the cold sea-water, cooled to its freezing- 
point or perhaps even slightly supercooled, has been enclosed in the small 
cold water-bottle it has begun to-form ice on the glass-walls, and the water- 
sample taken after the bottle came on deck again, has got a much too high 
salinity. It seems somewhat surprising that the salinity thus resulting has in 
many cases become rather uniform, (e. g. about 35°26 °/00). The explanation 
may be that the taking of the sample has required about the same time in the 
