CO885-(6-7) — Page 219

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PUBLIC RECORD OFFICE

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Reference :-

C.O. 885

6

PUBLIC RECORD OFFICE, LONDON

ALLY WITHOUT PERMISSION OF THE COPYRIGHT PHOTOGRAPH-NOT TO BE REPRODUCED PHOTOGRAPHIC-

27.

Surrounding bank.-The bank extends from the island 19 miles to the N.E., 33 to S.E., 9 to S.W., and 8 to N.W. Sand, coral rock, and coral bottom.

Depth from 13 to 21 fathoms throughout.

Best locality to build.-This spot is marked on the chart. It is the before-mentioned terrace, 48 x 30 feet.

This is the least exposed spot and the only level surface of

any size.

Best anchorage.-There are depths of from 8 to 17 fathoms, rock and sand, mile from the shore all round the island.

The current runs to the westward on the N. side, and to the eastward on the S. side therefore, when anchoring, one must be guided by the direction of wind and swell.

WEST COVE.

Best landing place for boat and cable. Pier, &c.—Landing anywhere is impracticable with even a moderate long ground swell such as-was running from the northward for three days after our arrival on August 28th.

West Cove (in my opinion) is the best landing place for boats and cable, but to make landing practicable in all weathers it would be absolutely necessary to construct a break- water extending from the west point of the detached rook to afford shelter from the north (as the wind seldom, if ever, blows from the westward).

The breakwater would probably have to extend at least 400 feet in a south-westerly direction in 6 or 7 fathoms.

On the south side of West Cove, 60 feet up the cliff, pools of salt water clearly point out that a very heavy sea sometimes rolls in.

September is said to be the calmest month in the year, and strong N. to N.E. winds are said to be frequent during the other months.

We landed on a ledge of hard rock from three to four feet wide, and 30 feet long, on the south side of the Cove. Here, a small iron pier, with a crane, might be constructed. From the ledge referred to, a rough ancient pathway leads up to the top of the cliff.

About 30 or 40 feet up the pathway, there is a spot where, without much labour, a level of 24 X 12 feet might be formed, and a hut built,

East Cove as a landing place for boats.-Landing was practicable, though difficult, in East Cove on the 3rd day after our arrival, when the northerly swell had moderated, and when West Cove was still impracticable,

At first glance, it would appear that East Cove is by far the best for a pier, &c., but the argument against it is as follows:-

It is open to the prevailing trade winds, which frequently are very fresh from N.E., and these are accompanied by a heavy sea which piles up by reason of the formation of the island, and, made worse by the heavy "back" wash," breaks heavily outside of, and on, the bar.

E. ROOKE,

Captain.

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GEOLOGICAL REPORT ON NECKER ISLAND.

1. The whole island is of a subaerial volcanic origin, and is entirely composed of the products of eruption, but the volcanic forces appear to have been quiescent for a considerable period, as the superficial rocks are much weathered (specimen A.).

2. The lava occurs both in the acidic and basic types, the colour varying between iron- grey, reddish brown, brown and black.

Its upper surface presents a very rough and rugged appearance, is very hard, and breaks with an uneven fracture.

The structure on the surface is scoriaceous and cellular, and in some places, on breaking into it, amygdaloidal, the vesicles in the latter case being filled with a sulphurous deposit.

This cellular structure disappears, however, towards the interior, where the lava becomes closer grained and more compact.

3. The island is traversed by sheets and dykes of intrusive rock, the latter appearing

to run, more or less, in a N.E. direction, and are very prominent.

4. These dykes vary much in breadth. The largest, which occurs at the western end,

is about 12 feet broad, and forms a natural wharf in the best sheltered part of the island, i.e., in West Cove.

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