The times. (Owosso, Mich.) 1882-1897, 1886-06-18
Color Of the Sea.

The changes in the color of the sea
have attracted the attention of seafaring
men from the earliest times, says wri-
ter in Science for al. TLey struck with
wonder the Phenicans when first they
ventured out of the Mediterranean into
the Atlantic; they excited the astonish-
ment of Columbus and terrified his COM
panions while in search of the far-famed
India and they are no less Il surprise to
the modern navigator, to whom the
march of discovery has left few unex-
plored regions in store. Numerous
theories were offered in explanation of
these changes, some ascribing them to
the varying color OF the sea bottom,
some to differences in depth, others to
the presence of certain coloring sub
stances. others again TO the chemical
composition OF the water. Most of these
suggestions contained an element OF
truth, although no one of them, taken
by itself, sulliced to account for altera-
ton in color which has often been OBJ
served to occur in the course of u few
hours sail, and within distance meas
uring less than a ships length. OF late
years, as the reader is aware, numerous
scientific expeditions. have been fitted
out and dispatched by the governments
of England, Norway and America for
the express purpose of exploring the
secrets of the deep. Among the prob
lens which have now for the first time
received satisfactory solution, new
light has also been thrown upon the
conditions, which affect the color of the
sea water in every part of the ocean,
thus completing the information for
which we were indebted to the unalded
eXertions of earlier travellers. One of
the most widely distributed contrasts of
color is that which is known to exist be-
tween the intensely blue seas situated
between the tropics and the green seas
of higher ATTITUDES. 1t appears, as the
result of recent observations and more
especially of series of experiments
made on board the German frigate Ga
Zelle, that there is an intimate relation
between the colors of sea-water and the
proportion of salt held in solution by
the latter. On comparing the specific
gravity of green water with that of blue
water, it was found that the latter is al
ways heavier than the former, and,
therefore, contains more salt, the two
differently colored waters being sup
posed to have the same temperature.
In other words, the greater or lesser in
tensity of the blue color of sea water
may be taken as direct index of its
sadness and of its specific gravity, so
that when we observe the color of the
water successfully change from deep
blue to blush green and dark green
we may conclude that the water has be-
come ut the same time less salt and less
heavy. This result agrees with the ex-
perience of navigators in every part of
the ocean, for as the vessel proceeds from
the dense and salt waters of the tropi-
cal regions toward the lighter and fresh
or waters of higher ATTITUDES and of the
polar regions the color of the sea is seen
to change from an intense blue to
greenish blue and green tint. There
are, however, numerous exceptions.
Green seas are met with between the
tropics and blue seas are encountered
in the temperate region, and even with
in the Arctic circle, but these excep-
tons, far from contradicting, only tend
to confirm the above rule.