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Appendix No. 4.

SINGAPORE.

Headings of discus-

sion on sea defences.

Western defences-

Mount Siloso.

Description of entrance.

Description of site,

Difficulty of design.

Disposition of armament.

Blasting operations.

General description in Report dated December 26, 1878.

Concrete escarp.

Eastern defences.

Battery-Blakang Mati East.

Site.

Disposition of arma- ment.

waters would be doubled, and there would be no need to fear the results of the operations undertaken by our ships, which would be left independent of their ports. This, then, will be the condition, under which I propose to discuss the further defences of Singapore.

16. Leaving out for the present the question of land defences, let me briefly describe :-

I. The defences that have already been constructed.

II. The purposes which these defences fulfil.

III. The points in which they fail.

IV. The extension which should be made, on the supposition that the New Harbour and coal

stores only are to be made safe against attack and destruction.

V. The extension that should be made if the town also is to be made secure.

VI. The further extension that should be made in the event of its being determined at any time to make Singapore a place of first Imperial importance, on one of the crowded highways of the world.

I.

17. The western entrance to the New Harbour is defended by one battery only on Mount Siloso, at the extremity of the Island of Blakang Mati, together with a line of submarine mines consisting of eight 500-lb. ground and six 100-lb. electro-contact.

18. The entrance itself is but 260 yards wide, and through this the tide runs at the rate of 4 knots per hour at springs, so that vessels cannot manoeuvre off the entrance, but are compelled to approach on a certain bearing, or run the risk of going on the rocks on either side. Mount Siloso consists of a ridge with an extreme elevation of 170 feet, running down in a north-west direction for a distance of 160 yards to an elevation of 120 feet, where it meets a narrow tongue running out to the extreme point. Along the whole sea-front and for some distance inside the entrance the ridge and tongue are bounded by a cliff, of which advantage has been taken in the design of the battery.

19. The slopes of the ground running to the cliff are very steep-from to; the width of the On a site of such ridge is narrow; and the reverse slopes on the north side of the hill are also steep. limited dimensions and of such a nature as this, it was a difficult task to design a satisfactory battery, and this difficulty was enhanced by the fact that the bearing of the ridge was north-west and south- east, whereas that necessary, so that the normal line of fire should sweep the bearing of approach, was north-north-west and south-south-east.

"C"

20. The armament with which this battery is provided are three 7-inch muzzle-loading rifled guns of 6 tons on naval slides, running upon "A" sweep-plate racers, and two 64-pounders on racers, firing over a 5 ft. 6 in. parapet. On the left of the battery is a 7-inch gun firing through an are of 120 degrees (by an addition to the sweep-plates), and commanding a zone from the front of Blakang Mati to the channel of approach. On the right of the battery, at a lower level, are the other two 7 inch guns sweeping the whole area of approach. In the centre of the battery, at an intermediate level, are the two 64-pounders en barbette, one 17-feet above the other, both having an all-round fire and sweeping the submarine mining field.

21. The tongue of land, referred to above, made a very inconvenient dead angle in front of this field, and blasting operations were therefore resorted to for its removal, so that, as the site stands at present, a glacis extends in front of the right 7-inch guns, having a gradient equal to their maximum depression, whilst above this glacis is another glacis swept by the 64-pounders. A narrow rocky parapet has been left unexcavated between the two glacis, as its presence with the present design is immaterial, whilst it will prove of use if the work be hereafter extended to Rimau Point, on the flat surface made by the excavation.

22. For a full description of the construction and design of this battery I must refer to my Report dated the 26th December, 1878. Suffice it here to say, that a thick concrete core has been constructed throughout; that suitable accommodation for ammunition and the service of the guns has been pro- vided; means of protection against a coup de main devised; and the details of the battery generally so designed that the work already done will all prove of use when funds are available to make it of a more permanent character. I may remark that it is not noticed in the Report referred to, that the treacherous nature of the soil compelled the construction of a concrete escarp nearly throughout, so that, in conjunction with the cliff in front, the battery, even as it now stands, is far from not being a formidable object.

23. The eastern defences consist of two batteries constructed at Blakang Mati East and Mount Palmer, with redoubt on Mount Serapong, to defend the entrance of the New Harbour, and a third battery at Tanjong Katong to aid in the defence of the roadstead and town. The submarine mining field at this entrance of the harbour is defended by eight ground mines of 500 lbs., and thirty-two electro-contact mines of 100 lbs. A full description of the submarine mining establishment at Pulau Brani and general scheme of torpedo defence will be found deseribed in my Report dated the 24th August, 1878.

24. This battery is constructed on a hill 140 feet high, forming a distinct feature of itself, at the eastern extremity of the island. The ground available for battery purposes is the shape of a double headed rail, with the northern member smaller than the southern, and the eastern concavity slight, in comparison to the western. It is on the southern member on a frontage of 160 yards from centre to centre of the extreme guns, that the battery has been constructed, the left flank crossing the neck, and presenting, at its junction with the gorge, a long exterior slope falling to the concavity alluded to. The northern member has an additional frontage of about 100 yards, and is surrounded by a musketry parapet which, at the gorge, crosses at a falling gradient the western concavity of the hill to join the covered way of the work itself.

25. The armament of this work are four 7-inch muzzle-loading rifled guns of 6 tons on naval slides, running upon A" sweep-plate racers, and two C4-pounders on "D" racers, with high

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