have originated in the disseverment of a single one. Male consists of
three perfectly characterised atolls, of which the shape and relative
position are such, that a line drawn closely round all three, gives a
symmetrical figure; to see this clearly, a larger chart is required than
that of the Archipelago in Plate II.; the channel separating the two
northern Male atolls is only little more than a mile wide, and no bottom
was found in it with 100 fathoms. Powell's Island is situated at the
distance of two miles and a half off the northern end of Mahlos Mahdoo (see
Figure 4, Plate II.), at the exact point where the two sides of the latter,
if prolonged, would meet; no bottom, however, was found in the channel with
200 fathoms; in the wider channel between Horsburgh atoll and the southern
end of Mahlos Mahdoo, no bottom was found with 250 fathoms. In these and
similar cases, the relation consists only in the form and position of the
atolls. But in the channel between the two Nillandoo atolls, although
three miles and a quarter wide, soundings were struck at the depth of 200
fathoms; the channel between Ross and Ari atolls is four miles wide, and
only 150 fathoms deep. Here then we have, besides the relation of form, a
submarine connection. The fact of soundings having been obtained between
two separate and perfectly characterised atolls is in itself interesting,
as it has never, I believe, been effected in any of the many other groups
of atolls in the Pacific and Indian seas. In continuing to trace the
connection of adjoining atolls, if a hasty glance be taken at the chart
(Figure 4., Plate II.) of Mahlos Mahdoo, and the line of unfathomable water
be followed, no one will hesitate to consider it as one atoll. But a
second look will show that it is divided by a bifurcating channel, of which
the northern arm is about one mile and three-quarters in width, with an
average depth of 125 fathoms, and the southern one three-quarters of a mile
wide, and rather less deep. These channels resemble in the slope of their
sides and general form, those which separate atolls in every respect
distinct; and the northern arm is wider than that dividing two of the Male