— 187 — 
Einar Lea’s hydrographical investigations, 1910—1I9I2. 
In spite of these objections and disabilities however, which previous experience 
had already indicated, I nevertheless considered it advisable to continue the current 
investigations, and applied to the Government for permission to repeat, in the years 
1910—1912, the May cruises along the Sognefjord section. These investigations were 
carried out during the years in question by Einar Lea, who endeavoured, not only to 
collect further material, but also to arrive at some means by which it might be possible 
to test the accuracy of the methods employed. In particular it was desirable to ascertain 
how far such sections of the Atlantic Current might be relied upon to give a truly charac- 
teristic and representative view of the hydrographical conditions prevailing at that 
season of the year. Mr. Lea’s treatise on the subject has not yet been published; he has, 
however, furnished me with the following brief survey of the principal results obtained. 
In consideration of the importance of these results as bearing upon the questions dealt 
with in the present work, I give this preliminary report in extenso. 
Methodical hydrographical investigations. 
»The hydrographical investigations of May 1912 were carried out with a view to 
obtaining material from which it should be possible to determine the representative 
value of a hydrographical section. Observations were therefore made both on the out- 
ward and homeward voyage, on approximately the same course, viz., between the mouth 
of the Sognefjord and a point situate at Lat. 63°43’ N, Long. 5°11’ W. 1 thus obtained figures 
for two hydrographical sections (A and B in figs. 117 and 118) along the same line, 
both with the same number of observations, and with but slight difference in point of time, 
the one series being taken between 10.45 a. m. on the 24th of May and 4.45 p. m. on May 27th, 
the other between the afternoon of the 27th of May and 10.30 a.m. on May 30th. 
»A comparison of these two series of observations will serve to indicate the variations 
which may occur in the section during a very short time. Some of the possible comparisons 
are shown in Table 1. This table gives, for both series, the figures for average surface 
temperature of Atlantic water (> 35.00 % ), average temperature of Atlantic water 
at intermediate depths, quantity of heat in Atlantic water, extent of coastal water area 
(< 34.00 % ) and finally for difference of average temperature of Atlantic water at the 
surface and at 200 metres’ depth. 
»These are the factors which have been employed by HeELLAND-HANSEN and NANSEN 
in their comparisons of the fluctuations in the growth of fir, variations in climatic con- 
‘ditions, in the quantity of cod liver, in the yield of the fisheries, etc. All calculations 
have been schematically rendered, as in the comparisons made by the two writers above 
mentioned. 
Tab. 1. 
Section A. Section B. Difference 
Mean surface temperature of Atlantic water..... 2.37 3°.04 0°.33 
Mean temperature at intermediate depths....... 7°.55 TAL 0°.14 
OQuantityzoraheatere ne see ee 906 955 49 
Extent of coastal water area (< 34.00 % )...... 4.12 km?. 3.88 km?. 0.24 
Difference in mean temperatures at 0 and 200 m 
ep N ehe ee 12a 117,18 0°.08 
