New-York tribune., 1842-03-29


2G0O feet high and B a shoul in the sea, when
c c is the sea level. Now il the cora grow on both
islands US they sink gradually until it be 1000 feet
thick we shall haze attolS at the SUBMITS. If the
,op be washed. so that the corals Will not grow,
ring will be formed and grow up and we shall
have n lagoon a will become cncircled IS
land for ages, until i, is submerged and then the
rising coral will form a lagoon. So that this Ia
goos island really represents n 0Sun&emmountoin.
This may be seen at Tahiti, in Gamblers grosp,
and in the Dangerous Arctipelago-an area of
1000 miles in one direction, and 600 in the other.
From this YOU may infer what must have been thu
vast differences in level Of so vast Take
any= continent containing a thousand mountains,
and how very great difference will there be be-
tween the elevation of the different summits.-
What difference between the high and low =
And what an amount of subsidencc must take
place before they are all so sunk that shall
ace only tho toprost uponthc .nmc level and yet
to this are we led y the theory of subsidcncc; nor
should we be terrified or frightened out Of any
sound theory by contemplating the vastness of the
results to which.itS lead
may as we'll mention that this theory of suhsi-
dcncc was not invented for the purpose of eXplnin
ing these phenomena. Long before DARWIN had
made his examinations of these coral islands, in
1885, | published my opinion upon this point, that
the sinking downof the Pacific nj ghtbe In crcess:
that its depression might be greater than its up
heava. For in no other way could we explain
how such a multitude of islands should exist first
At a level and now more than GO feet above the
surface Hcnderson's Island is about 60 feet
above and the Tonga islands Of Capt Cook are
tbout 20 or 80 feet he theory then, not
made tor the purpose of fitting the facts--though
it is a perfectly Legitimate reason for adopting
theory that you find it will explain all the know;
,henomena which 10 other theory will explain
Still il is somewhat more satisfactory ii the prin-
rpc was not formed expressly TO suit the facts Of
the case argued that if there equal
amount of upheaval and depresson--supposing
motion of oscillation-amovcment up we'll aS
lown--lo take place, large masses OF coral.
will be raised abeve the level OF the and that,
unless We assume that the downward movement is
in excess we are impcllcd to conclude the coral
would nor have remained on the level. For il il
sink 80 feet in ,cen.ury the coral would grow up
in that time 80 feet:-if ii rose ,enteet should
then find the solid ground of the coral ten feet
higher up. Iy YOU reflect YOU will see that it is quite
impossible to have nuTsber OF Islands Just
on a level without supposing the sinking 10 be
slightly in excess; and when you lind that tins will
explain the Formations OF ;,t,ols aad encircled Is
lands YOU must be skeptical ii you reject Dle eyi
dence in favor Oft especially when it j: ascer-
ancd that in Greenland the land is sctting-that
| there is u sinal! subSldcnce III the Bay ct Bal;t-
| al the mouth Of the Indus. and along parts OF the
| coast OF South America. But whar shall say
| when forced To conclude that. not only
must there have becna sinking down OF the floor OF
the ocean 10 bring all lis mountains TO the saln.
| hight bu, that all must have gone down grad
,lally as necer to sink one hmdrs2 and ttren.g
feet at once Fo, il there had ever been fall ii
,yonli
all would have pe,iShe and no new ones would
spring up. The whole process of subsidence then
must have gone on at very gradual rate--not
more than few wards al any one tlrnG.
#Bu, when islands are rising and we find that 4
large proportion Of the islands III these
volcanic islands, or that in part Of them are
volcanoes in active operaton,l IN tins case wc.
have coral reefs. but they do not encircle the
islands; but shall have Il formation called by
Darwin, triNSing reefs; reefs tlinslng the Short.
as near rs the zoophytes could live. There Is Il
small island OF Sumatin oversprcad al all nights
from the coast 10 200 OF 300 ieatzabove, wihcoral
shells OF the tri4Gchna. At the sameztime this
uphc.val has not carried the island as Far above
as it mus, before have been below the level
The coastot Sou,h America is ncwherc nocoral
grows. Why il is that zoophytrs will motive there
is not perfectly explained any moro thar why none
g,ow in the .lilanlc. The Atlantic is warm enough
and has all the necessary conditions but except
on the borders oi the suli->trc;.m coral islands
are found on the coast situated must tavorably in
'!H' tropical region; At present we canno more en-
plan ihis than why certain plants do not grow in
'he lznlted States; why roses are no, indigenous
IN the Southern hemisphere, &c. Blu, in the geo
graphical distribution OF plants the A,ithoy OF Ma
tnre has given certain laws; and so with the zoe
phycs They do no, foursl4 on the atlantic coast.
The coss' OF South Nnlerica IS coast OF upheaval
Sc far as we can Judge. here arerolcanoes here.
and animals and shells found at yarious nights
Yet there are 10 coral islands. Thenin Gambler,
group, in Tahiti and the Friendly Islands and in
the Dangerous Archipelago a,tols which have
HAT tops; here suppose there were stationary