356 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
part of the North Sea between Norway, Iceland, and Jan Mayen. 
The plan of work from a hydrographic point of view was largely 
inspired by the very valuable investigations by the Swedish scholars 
Otto Pettersson and Gustaf Ekman, in the Skagerack, to solve similar 
problems. The plan comprises two parts: 
1. The determination of the temperature and salinity in order to 
understand the distribution of the different layers of water and of 
the currents, both at the surface and in the depths. 
2. The recording of the changes which take place at different 
seasons of the year and during a series of years. 
Thanks to the labors of Fr. Nansen, director of the international 
central laboratory at Christiania, and of B. Helland-Hansen, it can 
be said that to-day the first part of the plan is nearly completed, and 
successfully. The temperatures and the salinities have been recorded 
with all the desired precision in the seas bordermg upon Norway, and 
the same has been done with regard to the principal currents, with the 
characteristic variations. Concerning these currents, whose study is 
one of the principal aims of oceanography and presents very great 
difficulties,t we are specially well informed as to their direction, but 
we have less information as to their speed, although on this aspect 
we have obtained very interesting data, especially in the deeper parts 
of the Gulf Stream. . The second part of the program is under way 
but much less advanced, because in winter the waters of the Nor- 
wegian Sea are troubled by almost continual storms; frequently there 
occur, at short intervals, marked changes within restricted areas. 
Variations in the distribution of different layers of water, in the direc- 
tion and speed of the currents, can be determined only by constantly 
collecting records from a great number of adjacent stations. 
We now know the origin and the characteristics of the principal 
layers of water, affording the two learned Norwegian oceanographers 
the basis for a monograph of the hydrographic conditions of the sea 
which washes the shores of their country. An approximate estimate 
has been made of the volume of water and the amount of heat brought 
by the Gulf Stream into that sea. Now, the amount of heat coming 
from the warm current has a marked influence on the winter climate 
of Scandinavia. Records kept continuously during the month of 
May have shown that the annual variations in the amount of heat 
from the Gulf Stream correspond to variations in the temperature of 
the air in that country. Thus, accordmg to the amount of heat 
brought in by the current, measured and calculated in the month of 
May, it should be possible to predict whether the following winter 
will be warmer or colder than usual. The temperature of the littoral 
waters in May is correlated with the rainfall of the preceding year in 
1 Cf. Ch. Gravier, ‘‘ Les récentes recherches océanographiques en Norvége,”’ in the Revue gén. des Sci- 
ences pures et appliquées, 1909, No. 2, pp. 84-89. 
