OBJECTIONS TO THE THEORY OF SUBSIDENCE. 289 
inner channels may be made, by the drifting of coral sands. 
The action with coral sands is essentially the same as with 
other sands; and illustrations of this drifting process occur 
along the whole eastern coast of North America from Florida 
to Long Island. We there learn that drift-made beaches run 
in long lines between broad channels or sounds and the ocean ; 
that they have nearly the uniform direction of the drift of 
the waters, with some irregularities introduced by the forms 
of the coast and the outflow of the imner waters which are 
tidal and fluvial and have much strength during ebb tide. 
The easy consolidation of coral sands puts in a peculiar feature, 
but not one that affects the direction of drift accumulation. 
b. The great barrier reef off eastern Australia, a thou- 
sand miles long, has some correspondence in position to the 
sand-reets off eastern North America. But it is full of irreg- 
ularities of direction and of interruptions, and follows in no 
part an even line. In the southern half, it extends out one 
hundred and fifty miles from the coast and includes a large 
atoll-formed reef; in the northern half, the barrier, while 
varying much in course, is hardly over thirty miles from the 
land. There is very little in its form to suggest similarity 
of origin to the drift-made barriers of sand. 
c. In the Pacific Ocean, the trends of many of the coral 
island groups, and of the single islands, do not correspond 
with the direction of the oceanic currents, or with any eddy 
currents, except such as are local and are determined by 
themselves. 
Near longitude 180°, as the map of the Central Pacific 
(Plate IX.) illustrates, the equator is crossed by the long 
Gilbert (or Kingsmill) Group, at an angle with the meridian 
of 25° to 30°, and not in the direction of the Pacific current 
which is approximately equatorial. This obliquely crossing 
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