CHAPTER VI. 
NortH Manos Bank. (Plate XI.) 
MAHLOSMADULU is divided by deep channels into three banks, each of which has signs 
of an approaching atoll-condition in series of circumscribing reefs. To the north of the 
whole bank and separated from it by a deep channel, 24 miles wide, with no bottom at 
100 fathoms, hes a small reef having at its opposite ends the two islands of Ettingili and 
Alifuri (Plate IX.). The north bank or North Mahlos is 34 miles long by 13 broad in 
the centre, and extends almost as an oval from north to south. At the south end the 
Moresby channel, 2 miles broad and 125 fathoms deep, separates it from a central smaller 
bank, Mid Mahlos, triangular in shape and pointed to the west. This again is separated by 
a channel of 110 fathoms, less than 1 mile broad, from the South Mahlos bank, 19 miles 
from north to south by 22 miles from east to west. The three banks from north to south 
cover areas respectively of about 320, 35 and 270 square miles. 
There is no evidence to show clearly whether the three banks of Mahlosmadulu were 
originally formed as distinct upgrowths, or whether they became disunited from one another 
as their development proceeded. The probabilities incline to the second alternative, but the 
point is one which requires to be considered rather in connection with the next chapter. 
The gross and minute characters of the reefs over the whole Mahlos bank are so uniform, 
that it is obvious that all must have been formed contemporaneously and are closely 
connected. The reefs on both sides of the three banks merge into one another in such a 
manner that any original separation into smaller banks seems impossible. The whole bank 
would be subjected to the same monsoon currents, which in this position set almost east 
and west. Moreover—and this is probably of greater importance—the tidal wave which 
travels along the lines of latitude and extends to the bottom of the ocean, would be 
resolved into current on meeting a ridge extending north and south such as the Maldives. 
As the banks grew up on the ridge the rate and hence force of the current would 
naturally be much accentuated. The two channels in Mahlosmadulu are in the position 
where this current would act with greatest effect, in that the bank forms a very open 
bay to the west and there is to the east an inlet, right opposite the deep passage between 
Miladumadulu and Fadifolu. That the current may be of very considerable force was clear 
on Nov. 29 and 30, 1899, when after fine, almost calm weather we found it in the deep 
channels between the three parts of Mahlos varying between 5 and 6 knots per hour. 
On the followimg day in the three shallow passages between Inguradu and Berriam-faro the 
current set constantly to the west, and at no state of the tide was less than 2 to 3 knots. 
In accordance with all our experience in the Maldives the current must extend to the bottom 

