The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-03-14
HOW ARE CORAL REEFS NADER
Boring Into south Sea AtOH to Dis
cover the Solution of a Problem
which Darwin Didn't Settle.


From the London Standard.
A coral reef Is always a delight to a
naturalist, but it is also very often a per-
plexity. 1t is well known that the coral
polyps can only flourish in sea water and
under certain conditions in regard to it's
purity and it's temperature. To explain
the origin and development of the masses
which skirt coasts and are known as
ringing reefs is comparatively easy. It
is more difficult to account for the larger
masses, rising from comparatively deep
water, not seldom several miles from land
and extending at times for long distances.
which go by the name of barrier reefs.
But the chief difficulty is to ascertain
the origin and development of the masses
called atolls, which are more or less ring
shaped, though they do not invariably
rise in all parts above the level of the
sea. This question has been for many
years a subject of keen discussion among
naturahsts.
An explanation, proposed rather more
than half a century ago by Charles OAR
win, after his return from the voyage of
the Beagle, obtained for some years very
general acceptance; but dissentients grad
ually appeared, and after the return of the
Challenger, nearly twenty years ago, the
controversy was revived-largely by the
writings of Dr. John Murray, who had
been one of the scientific staff on that
vessel-and ever since it has been brisk
enough. Much depended, for reasons pres
emily to be stated, upon the actual struct-
ure of the atoll; as to whether it con-
sisted of a mass of coral approaching,
perhaps, 1000 feet in thickness, or whether
it was a mere skin, not deeper at most
than about $50 feet, resting upon a rock
of a different nature. That, of course,
could only be settled by boring into an
atoll and examining samples of the rock
to something like the first named depth
Twenty or thirty years ago this would
have been slow, arduous, perhaps inn
possible, task but such improvements
have been made in the machinery for bor-
ing and the process has been so facili-
tated, especially by employing the mineral
called the carbonado, a variety of the dia-
mond, in arming the drill, that there was
good hope of a successful result
The question of making the experiment
was raised before the British association
by Prof Sollas of Dublin and after some
years of discussion was brought before
the Royal society as one to which portion
of the grant annually made TO 1t by the
government for the furtherance of science
might properly be devoted. A committee
was appointed by that body, and applica-
ton was then made to the lords of the adj
miralty to be allowed the services of one
of their surveying ships. The general plan
of operations had been already determined;
the project had also been cordially espous-
ed by men of science in Sydney, and IL
had been decided, after a conference with
them, that on the whole Funafuti, one of
the Ellice group, lying north of the Fiji
islands, would be, under the existing cir
cumstances, the best place for making the
attempt. A favorable reply was received
from the admiralty stating that her ma
jesty's ship Penguin, under the command
of Capt. Field, which was then engaged in
making surveys in the southern seas,
would convey the party and their plant
for boring from Sydney to Funafuti. rem
der them all possible aid during their stay.
and meanwhile make a thorough survey of
the vicinity of the atol.
OF the rival theories between which II
was hoped that experiment would decide,
the following had attracted most attention.
Darwin had regarded atols as the effects
of subsistence. This was his supposition.
First, fringing reef forms round and is
land, then the latter gradually sinks: the
coral polyps, which 1t is believed cannot
flourish at a greater depth than . faith
oms, keep growing upward. but those at
the edge, being better nourished. increase
faster than those on the inner side of the
reef, so that gradually Il ceases to be con-
tinuous with what is left of the island.
Subsistence goes on till the latter has fin
ally disappeared then a ring-like atoll
is left, which rests on the foundation of
an ancient ringing reef Thus Darwin
regarded an atoll as a monument erected
by nature TO the memory Of a drowned IS
land. But DR.. Murray repudiated the idea
OF subsistence altogether, and proposed a
very different explanation.
We may take this hypothesis as repre-
sentative Of Darwin's opponents. though
they differ considerably among themselves
He Dostulated the existence Of a submarine
volcano. If this did not come near enough
10 the surface TO allow coral pOlyps TO
grow on its top, IL was heightened by the
accumulation Of marine organisms: finally.
when 1t came within soundings OF about