The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1898-11-05

Scotia, and the highest reading in the
open ocean Is 80 degrees Fahrenheit. re-
corded In the tropical Pacific both north
and south Of the equator, though readings
or "a and SO degrees Fahrenheit are re-
corded in the Red Sea and Persian Gulf.
respectively.
The greatest known range of tempera-
ture OF the surface waters throughout
the whole world is thus 20 degrees Faren-
heft from 26 degrees to So degrees). He
goes on to show that the range of tenn
perature has very important effect in
bringing about vertical circulation in
ocean waters. In the equatorial regions,
where there is hardly any variation in
surface temperature. the warm water re-
mains at the surface and there relatively
cold water comes nearer to the surface
than in those regions in temperate zones
where there is a wider daily and annual
range. The cooling of the surface layers
at night and during winter in temperate
regions causes the salter water of the
surface to sink through the underlying
layers, carrying with them heat and at.
mospheric gases to the greater depths
The effect of freezing in the polar re-
gions is in the end similar to that of evap-
Grafton in warmer ATTITUDES. The lighter
ice is separated from the denser mother
liquid which sinks to the greater depths,
leaving the Ice on the surface These
statements as to the effects of range of
temperature might be illustrated by ref
erence to many parts of the ocean.
= It will be sufficient to refer to the, most
striking example, in the southern hemi-
sphere, where there is a band of large
range of temperature right round the
world The warm tropical waters, which
coasts of South America, Africa and Aus
tralia into the Great Southern Ocean,
there become cooled as they, flow to the
east before the strong westerly winds. On
account of their high salinity these trop-
ical waters can suffer much dilution with
Antarctic water and still be denser than
water from these higher ATTITUDES at the
same temperature Here the density oh
servations and the sea water gases fndi-
cate that large part of the cold water
probably leaves the surface and sinks
toward the bottom of the Southern Ocean
between the ATTITUDES of 45 degrees and
oms the temperature in one part of the
ocean may differ from that to be found
in some other part at the same depth by
at at 500 fathoms there may be be-.
tween one part and another a range
of as much as 20 degrees Fahrenheit; at
grees Fahrenheit. and at 1900 fathoms not
exceeding degrees Fahrenheit. A con-
sideration, however, of all the available
observations shows that there is no EVIL
dence of any annual variation of tenn
perature at any one spot in the ocean
at a depth of 100 fathoms; and at depth
OF fifty fathoms no annual range greater
than degrees Fahrenheit appears to be
indicated. This remark applies especial
ly to the open ocean: but although we
have no direct observations, still 1t Is
most probable that along certain coasts
a wide range of temperature is OCCASION
ally produced at the bottom in depths of
fifty and even 100 fathoms. due to the
lateral shifting of large bodies of water
movements like these comes especially
from regions where polar and equatorial
currents meet or run alongside of each
other in different directions, as. for in
stance, in the case of the Gulf stream
and Labrador current off the eastern
coasts of North America.