238 
PACIFIC SCIENCE, Vol. II, October, 1948 
ganic matter, presumably shoals of fish or other 
bathypelagic organisms. It is possible that a 
kind of intermediate fishing grounds along 
the equator may be made accessible to exploi¬ 
tation along commercial lines through a future 
development of the midwater trawling net. 
Preliminary measurements of the geothermal 
gradient in deep-sea deposits were made by 
means of a geothermometer of special con¬ 
struction. The conditions on the bottom as 
well as those prevailing at the surface, i.e., wind, 
waves, swell, and currents, necessarily severely 
restrict the use of this instrument for it has to 
be plunged down into the deposit to a depth 
of about 12 meters and remain there until 
equilibrium with the surrounding temperature 
has been attained. Only two successful shots 
could be made in the Pacific Ocean,, both giving 
unexpectedly high values for the geothermal 
gradient there (between 20 and 30 meters per 
degree centigrade). A discussion of these re¬ 
sults, which indicate a more intense flow of 
geothermal heat upwards through the ocean 
bed than one has, for general reasons, been in¬ 
clined to assume, must be postponed until more 
data have been obtained. 
In summary it may be said that the new 
technique developed in Sweden for investi¬ 
gating the deep-ocean bed and its sediments has 
been found to work well in oceanic depths, and 
it promises a new and fruitful field of work 
on the border line between oceanography and 
submarine geology. When our cores have been 
examined by different kinds of analyses, a 
task which will require several years to accom¬ 
plish, new light will be thrown on problems 
regarding the deep-sea bottom, its morphology, 
and its sediments and their chronology. For 
the latter study both foraminiferal analysis and 
radioactive age determinations are available. 
The investigation of the deep-ocean bed, its 
stratigraphy, and its fauna manifestly calls for 
co-ordinated efforts on an international scale. In 
this future work Honolulu, with its famous 
Bishop Museum and its University of Hawaii, 
appears destined to become the foremost center 
of research in the central Pacific Ocean. 
REFERENCES 
Johnson, Nils G. 1946. On anti-rachitic 
ultra-violet radiation in the sea. Oceanog. 
Inst. Goteborg, Meddel. 8: 1-16. 
Kullenberg, B. 1947. The piston core-sam¬ 
pler. Svenska Hydr.-Biol. Kom . Skrifter III 
(Hydrografi), 1(2): 1-46. 
Pettersson, H. 1937. Das Verhaltnis Thor¬ 
ium zu Uran in den Gesteinen und im Meer. 
Akad. d. Wiss. Wien, Anzeiger Nr.l6: 1-2. 
-• 1943. Manganese nodules and the 
chronology of the ocean floor. Oceanog. Inst. 
Goteborg, Meddel. 6: 1-43. 
--— 1945. Iron and manganese on the ocean 
floor. Oceanog. Inst. Goteborg, Meddel. 
7: 1-37. 
———- 1946. Oceanographic work in the 
Mediterranean. Geog. Jour. 107 (3,4): 163- 
166 . 
——- 1947. A Swedish deep-sea expedition. 
Roy. Soc. London, Proc. B, 134: 399-407. 
—- and B. Kullenberg. 1940. A vacuum 
core-sampler for deep-sea sediments. Nature 
145: 306. 
-—--— 1941. Vakuumlodet. Oceanog. 
Inst. Goteborg, Meddel. 5: 1—16. [In Swed¬ 
ish.} 
-— et aL 1948. Three sediment cores from 
the Tyrrhenian Sea. Oceanog. Inst. Goteborg, 
Meddel. 15: 1-94. 
Phleger, Fred B., Jr. 1947. Foraminifera 
of three submarine cores from the Tyrrhen¬ 
ian Sea. Oceanog. Inst. Goteborg, Meddel. 
13: 1-19. 
PlGGOT, C. S. 1936. Core samples of the ocean 
bottom. Smithsn. Inst., Ann. Rept. 1936: 
207-216, 6 pi. 
-— and Wm. D. Urry. 1939. The radium 
content of an ocean bottom core. Wash. 
Acad. Sci., Jour. 29: 405-410. 
-- - 1941. Radioactivity of ocean 
sediments. III. Radioactive relations in ocean 
water and bottom sediment. Amer. Jour. Sci. 
239: 81-91. 
———- —— 1942. Radioactivity of ocean 
sediments. IV. The radium content of sedi¬ 
ments of the Cayman Trough. Amer. Jour. 
Sci. 240: 1-12. 
Urry, Wm. D., and C. S. Piggot. 1942. Radio¬ 
activity of ocean sediments. V. Concentra¬ 
tions of the radio-elements and their sig¬ 
nificance in red clay. Amer. Jour. Sci. 240: 
93-103. 
Weibull, W. 1947. The thickness of ocean 
sediments measured by a reflexion method. 
Oceanog. Inst. Goteborg, Meddel. 12: 1-17. 
