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‘ Josephine,’ and lately hy the U.S. sloop ‘ Gettys-
hnrg,.’ rnnning down in a sonth-westerly direction
from ahont Cape Roca, inclnding the Josephine Bank
and Madeira, and giving its western honndary to a
tongne of deep water which passes in a northeasterly
direction between Madeira and the mainland
towards Cape St. Vincent. (See Erontispiece.)
Erom Teneriffe westward, except at one spot ahont
160 miles S.W. of the island of Eerro, where we
sonnded in 1,525 fathoms on the top of a ridge, the
water gradually deepened to the westward to the
depth of 3,150 fathoms at the bottom of a wide
valley which extends more than halfway across the
Atlantic. About long. 43° W. the floor began to
rise, and at long. 44° 39' IV. we sonnded in 1,900
fathoms on the top of a gentle elevation. Eurther to
the westward the depth again increased, and in long.
61° 28' N. we sounded in 3,050 fathoms at the bottom
of a deep western trough; the water tlien shoaled
rapidly np to the West Indian Islands.
On our next section from St. Thomas to Bermudas
we sonnded a little to the north of the Virgin Islands
in 3,875 fathoms, the greatest deptii known in the
Atlantic, and our whole course lay through a depression
upwards of 2,500 fathoms deep, showing th a t
the Avestern trough extended considerably to tbe
northward. Tbis Avestern valley Avas again traversed
between Bermndas and the Acores, the Avater sliailoAv-
ing at a distance from those islands, thus shoAving th a t
they formed the culminating points of a plateau of
considerable extent. BetAveeu the Acores and jMadeira
we recrossed tlie eastern valley, and onr coarse from
Madeira to the Cape Verde Islands, and soiitlnvards
VOL. II. U