DESCRIPTION OF THE EXPEDITION. 27 
and lagoon reefs average in breadth about 100 and 300 yards respectively. Their shoves 
behind are rocky, or covered with stones and sand, their character varying in accordance 
with the breadth of their fringing reefs. The reef-flats of each are very similar in 
appearance, being ordinary coral-flats, but the outer is evidently very largely built up 
by calcareous plants and the inner by animals. The former settlement was situated on 
the middle of the lagoon side and consisted of the regular buildings required for the 
preparation of oil from coconuts, together with a large number of houses, some built 
of coral-conerete, others of wood, but all raised to a height of 4 or 5 feet on built-up 
foundations, of which we counted about thirty *. 
On either side of Diamant the shore is raised by the piling up of sand by wind and 
waves, but nowhere does it attain a greater height than 8 feet above high-tide level. 
The centre part is lower, and in parts forms swamps, into which the sea has broken from 
the outer (7. e. north-west) side of the island, in places forming small backwaters, or, as 
they would be termed in Mauritius, barachois. One of these is barred up for fishing 
purposes, but the rest seem to be encroaching upon the land, as evidenced by fallen 
timber, &c. At the south-west end the island extends out into two points, with a bay 
between, while Grand Mapous, the next island to the south, likewise shows two points 
as if extending along to meet those of Diamant. Conuecting the two seaward or outer 
points are two lines of rock on the reef, which are exposed at low tide, while the large 
pool between the inner and outer points of each island has apparently about 6 feet of 
water. It was at once quite evident that the two islands had been connected along the 
reef, but that the sea had broken through into the centre lower-lying land and formed a 
barachois such as those which occur in Ile Diamant itself. The seaward points and the 
adjacent shores are now markedly washing away, as evidenced by undercut rocks, but it 
was uncertain whether the islands are not gradually becoming joined together again by 
sand being piled up along their lagoon or inner side. 
The whole island is now devoted to the cultivation of the coconut, but its central part 
was evidently at one time a large garden for taro (Creole “ songe,” Colocasia antiquorum), 
cassava, arrowroot, marrows, gourds, bananas, and papayas, while there were several bread- 
fruit trees. No indigenous jungle is left, and the whole surface of the ground in the 
swamps is covered by a creeper (like a wild bryony) known as “ pocpoe,” while the dried 
shore-ridges had coarse grass, with bushes of manioe (Scevola Koenigii) and veloutier 
tabae ( Tournefortia argentea) next the sea. Only about 45 plants in all were observed, 
and no cultivated plant beyond those mentioned, an extraordinary fact considering the 
large settlement formerly on the island, and one in striking contrast to the Maldives. 
True land-animals of all sorts were scarce, even in comparison with the other islands 
of the Chagos—not only in species, but in actual number of forms. This fact we are 
inclined to attribute to the vast numbers of mosquitoes, which breed in the swamps 
among the rotten and stinking coconut-husks. According to our observations they 
* Commander R. Moresby in his ‘ Nautical Directions for the Maldive Islands and the Chagos Archipelago,’ 
1839, states that the principal establishment was on Diamond Island, and that the group produced about 
34,000 gallons of oil yearly, being worked by an overseer and about 90 negro apprentices. He adds that plenty of 
poultry and pigs were obtainable, also fruit and vegetables at 6 Spanish dollars per cwt. iol 
5* 
