PACIFIC AND BEEUING’S STRAIT. 
east and west; generally about eighteen inches wide, neady ^rpe.^ 
dicular to the horizon, or dipping to the sent war . . 
is sometimes compact, sometimes vesicular, with few if any imbedded 
minerals, excepting one on Marsh Island, which “ntamed great qnan 
tities of olivine. Upon a small island contiguous to this, the 
dyke crosses the highest ridge, and divides on the eastern side into two 
parts which continue down to the water s edge*. 
Lieutenant Belcher, whose scientific attainments also ena 
to appreciate what fell under his observation, noticed every where 
trap formation ahoiinding in basaltic dykes also lying N. E; and S. ^ 
and seldom deviating from the perpendicular; or if they did, it was to the 
eastward. We are indebted to him for specimens of zeahte, carbonate ot 
Ume, calcareous spar, crystals, an alcime, olivine, f f 
and had our stay, and his other duties admitted, ’ 
have received from him a more detailed account of this interesti g 
There are no appearances of pseudo-craters on any of the islands, 
nor do they seem to have been very recently subjected to fire, being 
clothed with verdure, and for the most part with trees Conspicuous y 
opposed to these lofty rugged formations, raised by the 6^"’ 
is a series of low islands, derived from the opposite element, ow'^ 
their construction to myriads of minute lithophytes, endowed widi m 
instinct that enables them to separate the 
from the ocean, and with such minute particles to tear a ^endid struj;^ 
ture many leagues in circumference. A great wall o ^ 
may use L expression, already surrounds the islands, art by ^ 
remitting labour of these submarine . g^jAears 
surface of the water in all its parts. On the N. E. side, it a ready bears 
a ferl soil beyond the reach of the sea, sustains trees and other sub- 
jects of the vegetable kingdom, and affords even an habitation to 
' ”“'ln the opposite direction it dips from thirty to forty feet beneath 
the surface, as if purposely to afford access to shipping to the lagoon 
133 
* Mr. Collie’s Journal. 
