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from this range. This principal is the Soongie Saletar, which appears to flow through a long valley between a branch of this range and another range proceeding from the Bukit Temah group in a northerly direction. The western side of the Island consists of several ranges radiating apparently from the Bukit Temah group, and penetrated by valleys, some of them, such as that of the Kranjee, which flows northward to the old strait, and the Joorong, which flows southward to the Salat Samboolan, being of considerable length and terminating in broad creeks intersecting mangrove swamps. Between some of the ranges the only wide flattish tracts in the Island which are not alluvial are found. The lower parts of the valleys are mostly swampy, consisting of sand, clay and black peaty mud, of the latter there are considerable tracts constantly moist and exhibiting an extraordinary rankness of vegetation. Looking on one of these swamps covered with tall but slender trees, and dense underwood growing up rapidly, and from the looseness of the deep bed of black vegetable matter,--the accumulated remains of their short-lived predecessors, -destined soon to fall in their turn, and considering the deposits of clay and sand which accompany and give rise to it, it is impossible to doubt that we see nature repeating the precise process by which the materials of most of the ancient carboniferous strata were brought together. Towards the sea these forest marshes give place to mangrove swamps. An intelligent Chinese Gambier planter compares Singapore, not inaptly, if the eastern part of the Island be excluded, to an open umbrella, of which Bukit Temah is the top and the various rivers the ribs. If we suppose the Island to have been formed of a somewhat brittle material, and a strong blow from beneath to have struck it at Bukit Temah, from which cracks radiated in different directions, dividing or bifurcating in their progress, a rude idea of the lines of hills may be formed; or if we view the Island from west to east our old comparison to the section of a tree would serve us best. Bukit Temah and the adjoining hills form the stole from which one main trunk, about 12 miles in length, extends to the Red Cliffs with numerous branches. Several smaller trunks rise on the south side of the main trunk and extend for about 6 miles in a S. E. direction, also sending out a multitude of small branches. To the west the roots radiate to different parts of the coast, the tap root being about 7 miles long.
The hills of the first and second ranges in the order in which they are above noticed consist chiefly of sandstone (fine grained, gritty and conglomeritic) and shale strata. Towards the eastern extremities of the two next ranges similar rocks are observed. Further on soft clays of various hues, but mostly mottled white and red or purplish, passing into a soil of different shades of red, yellowish red, and brownish red, are observed near the surface, and occasionally protruding blocks of sienite and green-stone occur.
The hills of the eastern side of the Island seem to be principally sandstone with slight traces of shale. The western side is also for the most part sandstone and shale. At the N. E. extremity granite or sienite appears and it is also seen at several places along the N. and N. W. coast.
The superficial deposits which occur at various places are very remarkable. On some hills a red stiff clay resembling laterite is found. On many, imbedded in clay of different red and brownish hues, in irregular sheets or in thin seams, occur blocks of a ferruginous clay, rock or smaller stones and pebbles of various kinds and sizes. These will best be described hereafter by selecting particular localities where they abound.
I now proceed to notice the different hypothesis that have been or may be suggested to account for these appearances. Of the alluvial plains and valleys which ramify through the Island in all directions I need say nothing here, as they, in exposed beds at least, have all or nearly all been formed subsequent to the hills and their superjacent deposits, and are separated from the latest accessions of matter which these received at a period when they formed a multitude of little bays and long narrow inlets of the sea.
The first class of the hypothesis that may be offered in explanation of the superficial formations of Singapore, embraces those that contemplate merely the position, external appearance and size of the detached rock fragments.
Of these the first supposes the blocks, gravel, &c. to be the debris of older rocks deposited in the sea before the extrusion of the hills. If it be conceived that the elevation of the hills above the level of the sea was the same act with the protrusion of the strata of which they
are composed from their previous horizontal bed to their present inclined position, we are met by the fact that the superficial deposits are not in layers conformable to these strata, but are spread over their uplifted edges. If again, it be supposed that the hills were formed under water, and that after the accumulation of the gravel, &c. upon them, the platform from which they rise was elevated so as to cause them to emerge from the sea, we are met by other insuperable objections. Of these it is only here necessary to specify one, although looking to single limited localities the gravel deposits appear to be regularly disposed like beds derived from currents; when we compare one hill with another we observe far too much irregularity to allow this idea to be tenable.
2.-DILUVIAL HYPOTHESIS. As we extend our observations this irregularity is seen to be so great that we are irresistibly led to conjecture that its causes were diluvial instead of alluvial. In many places rock fragments of all sizes are confusedly intermixed with loose clay or sand, so that if due to aqueous action it must have been of an extraordinary and violent nature thus to have borne along rapidly masses of matter containing large blocks, and deposited them in such confusion, and that often on the summits of hills. A continued diluvial action of variable force might also account for the large quantities of rounded pebbly-looking stones, and the broad thin beds of smaller gravel-like stones that occur. Closer investigation however seems to discover an unanswerable argument against a diluvial theory in the fact that the larger rock fragments, and even the gravel, differ in different localities, often even when these adjoin each other, and that it has always been found that they have a certain correspondence with, or relation to, the subjacent rocks where these have been exposed. No decided boulder or drift has yet been noticed.
Colonel Low appears to have considered the scoriaceous, ferruginous rocks as boulders, but he gives no reason for this opinion. The gravel he refers to the concretionary tendency of soils impregnated with iron. I need not stop here to remark upon these evidently hastily formed views.*
I cannot mention Colonel Low, during so many years of official toil, almost the soli. tary votary of science and oriental literature in the Straits Settlements, without expressing the hope that he will not long with hold from this Journal the fruits of his present learned leisure.”
3.--DECOMPOSITION or Rocks In Situ. This, which is the hypothesis that next most naturally arises, would embrace many of the facts that are inconsistent with the sedimentary and diluvial suppositions, such as the local character of the rock fragments. The outcrops of the strata, which are generally highly inclined, would under meteoric influence, down to a certain line of depth which would descend with the denudation of the surface, suffer different changes according to the nature of the rock. The harder sandstones and shales would, split and break down into irregular fragments. The softer sandstones, clays and shales,-and of the latter especially the finely laminated beds,--would, under the combined chemical and mechani. cal influences of the air, rain, rapid transitions of temperature, &c., lose their distinctive original characters and gradually become uniform masses of sandy or clayey soils. Every heavy fall of rain would wash away the more superficial particles. According to the declination of the sides of the hills, fragments of rock of different sizes would be carried down by the pressure of water-moved soil and gravelly fragments. Where the hills were steep, larger blocks, from the gradual loosening of their beds, would descend to lower levels by their own gravity assisted by similar pressure from above. The summits and ridges of the hills would be most exposed to the action of sun and rain, but generally least so to the denuding power of gravity. Where the soil was loose sand, or where there were narrow summits, the process of denudation would be more active than elsewhere. The soil as it was formed would disappear, and only fragments of rock be left where the latter was of a nature to yield with difficulty, slowly and superficially to decomposition. Where the fragments pulverized more quickly, some soil would generally be found, always drawing additions from the rocks, but always a prey to the rains.
These considerations certainly explain the present appearance of many of the hills, and in every locality phenomena occur evidently due to the forces of which I have been writing. Ridges and summits are often found consisting almost entirely of rock fragments, and it might seem that these forces alone would be adequate causes for their occur
But on hills with extensive flattish summits, beds of fragments, sometimes large, --sometimes of all sizes mixed-sometimes uniformly small and gravel-like, lying under or in the soil at various depths, from
an inch to many feet, below the surface, are frequently discovered by sections for roads and pits for planting spice trees, &c. It is obvious that the hypothesis which I am now considering will not explain such cases.
There is another phenomenon of frequent occurrence connected with the position of fragmentary rocks which this hypothesis ought to include if it be made the foundation of any general theory. In sections across strata they are almost invariably seen to be more or less curved as they approach the surface. Before reaching it however they sometimes gradually, but often abruptly, lose their compact form and become masses of fragments. In some cases these are almost insensibly min. gled with the superincumbent soil till all trace of the stratum disappears. But it is not uncommon to see the curve pass into a line more or less horizontal, and even bent downwards, and the fragments streaming away as it were in a layer of which the direction seems to have no relation to the parent stratum, but which generally possesses or approaches to parellelism with the plane of the surface. It is true that of some of these cases the hypothesis which we are at present pursuing might seem to afford a solution. Thus suppose a thin layer of hard sandstone to rest on a bed of soft sandy clay or unlaminated shale, both inclined and having their outcrop on the slope of a hill, a certain depth from the surface of the slope would be subject to the action of meteoric forces which would cause the sandstone to break up into fragments and the sandy clay to become loose and open. The sandstone rubble, if heavy, might possibly tend to descend or settle in a perpendicular line through the upper pulverulent to the lower and more compact soil, and, at all events, as the soil below it was carried away, the rubble would descend along the line of the slope, the heavier fragments remaining at and near the point of outerop, those of medium size streaming further down the slope, and the smallest borne away with the fine sand and clay to lower levels ;--the possibility of the existence of such lines of rubble, their breadth down the slope from the line of outcrop, and the quantity and size of the fragments, being always determined by the texture of the recipient bed of clay or sand, and the declivity of the hill. Where the slope of the hill consisted of a succession of similar layers and beds, the lower layers of rubble would, in course of time and in favourable positions, become covered with soil brought