78 
PACIFIC SCIENCE, Vol. XII, January, 1958 
Spherules per kg salt-and carbonate-free sediment. 
Fig. 6. Number of spherules per kg. of salt- and 
carbonate-free sediment from Core 92. 
still higher than the numbers found in deep- 
sea deposits. No nickel was found to be 
present in these spherules. 
We infer, therefore, that most of the spher- 
ules thus collected are of terrestrial origin and 
are artifacts from industrial plants and weld- 
ing operations, which can be carried over 
large distances by wind. 
Hoppe and Zimmerman (1954), collecting 
magnetic spherules at Jena and other localities 
in West Germany, have arrived at the same 
conclusion and consider it impossible to avoid 
such contamination in localities in or near 
industrial districts. 
Based on these results we have planned to 
collect magnetic particles from the atmos- 
phere on ocean islands situated far from any 
industrial plants and as remote as possible 
from the shipping lanes across the sea. Such 
measurements, which we hope to organize on 
Pacific Ocean islands during the Geophysical 
Year, may be expected to afford evidence of 
true extraterrestrial spherules settling over the 
ocean surface and thus complement our stud- 
ies of the magnetic spherules in deep-sea 
deposits. Calling attention to the interesting 
results from the attempts at a magnetic drag 
over the ocean bottom from the "Galathea” 
Expedition, we consider the evidence in fa- 
vour of the magnetic particles reported by A. 
Bruun and his co-workers (1955) as being 
largely of cosmic origin to be very strong. 
On the other hand this method of using a 
superficial collector can only be expected to 
bring up extraterrestrial particles of recent 
origin. Moreover, a certain risk of contamina- 
tion with spurious spherules from coal- or 
oil-driven ships passing near the course of 
the "Galathea” cannot be altogether ex- 
cluded. No such risks are involved when ex- 
tracting magnetic spherules from undisturbed 
long cores provided one gets below the up- 
permost few centimeters of sediment. This 
method alone seems to allow of definite con- 
clusions regarding the frequency of meteoritic 
falls and their variations in the remote past. 
Quite recently the accruement of meteoritic 
fragments and dust to the surface of the Earth 
and its oceans has attracted the interest of 
meteorologists and climatologists. 
Mainly through the work of Bowen in 
Australia (1953) and of his co-workers in 
Spherules per kg salt-and carbonate-free sediment. 
Fig. 7. Number of spherules per kg. of salt- and 
carbonate-free sediment from Core 133. 
