and Habakkuk ii. 2. Palm-leaves generally undergo some preparation to fit them to receive the impression of the stylus. They are then called ollahs. The natives write letters to one another upon ollahs, which are neatly rolled up, and sometimes sealed with a little gum-lac. During the operation of writing, the leaf is supported by the left hand, and the letters scratched upon the surface with the pointed piece of iron. Instead of moving the hand with which they write towards the right, they move the leaf in a contrary direction, by means of the thumb of the left hand. To render the characters more legible, the engraved lines are frequently filled by besmearing the leaf with fresh cow dung. This substance is then tinged black, which makes the writing very plain. Sometimes this object is obtained by rubbing the lines over with coco-nut oil, or a mixture of oil and charcoal powder. The natives do not require tables to write upon; they can write standing as well as walking. Baskets for catching fish, shrimps, &c. are made of the ligneous ribs of the leaflet; the same substance is employed by the natives for many of the purposes for which we use pins. A bundle of these ribs is in universal use, as a broom, to sweep the cottages; and when an European asks for a tooth-pick, his servant brings him a portion of one of these fibres. Lately, I am informed, they have been recommended to be employed as a nucleus for bougies. In a domestic state, elephants are fed chiefly upon coconut leaves, and this animal evinces much sagacity in separating the elastic woody fibre from the thinner margin of the leaf. For temporary purposes, cadjan-houses are frequently constructed, both by natives and Europeans. During the insurrection in the Kandyan country in 1818, many of the sick were accommodated in cadjan-hospitals. Except the frame-work, every part of the house, walls, and roof, is formed of coco-nut leaves. They are capable of resisting all kinds of weather for a year or more. Το prevent thieving, the owners of topes frequently fix a Coco-nut leaf along the stems of fruit-trees. As the leaf rustles much when touched, a thief is cautious of ascending the trunk of the tree, lest he should alarm some of the inmates of the neighbouring huts. THUNBERG mistook the use of these leaves, and supposed that they supplied" the place of ladders, by means of which the natives could climb up, and gather the fruit."* * Travels, vol. iv. p. 192. In warm climates, it is customary to travel during night, with the view of avoiding the influence of an ardent sun. Torches then become necessary, and coco-nut leaves are chiefly employed for this purpose. By tying the leaflets close to the centre-rib of a leaf, the ignition is prevented from being to rapid. Torches of coco-nut leaves are commonly denominated chals [ooloo attu, Singhalese]; they are in constant use, to obstruct the inroads of wild beasts upon cultivated fields, more particularly of elephants. In the interior of Ceylon, every field under cultivation must be watch ed during night, to prevent the depredations which would be made upon the crops, were these animals to have free ingress. When burned, the coco-nut tree, especially the leaves afford a large proportion of potash. The caste of washermen avail themselves of this quality, and procure all the potash they require by the incineration of different parts of the Soap is very little used by the native washermen in Ceylon. tree. Boats are rowed with the centre-rib of the leaf, in which operation it forms a substitute for paddles. The end of this part of the leaf is sometimes well bruised, and thereby converted into a brush, that may be used for a variety of purpos es. The spaths, or fibrous covering of the blossoms, are inflammable; on that account they are often employed as torches. In some parts of India this part of the tree is soaked in water, and converted into coarse cordage, with which the thatch of houses is tied. (To be continued.) By ART. XLII.-On a Method of Splitting Rocks by Fire. MANY large tracts of the mountainous land of Scotland, which posses an excellent soil capable of cultivation, are incumbered by huge alluvial or detached blocks of stone; and the expense of removing these from the surface forms, in many cases, nearly the whole difficulty which stands in the way of their improvement. Where dikes, or stone-walls are required to enclose such land, the expense of thus clearing the soil is materially diminished by the countervailing value of the quarry which the field itself thus affords. But even in these cases, where the blocks are too large to be weighed and removed entire, a considerable expense is incurred by the necessity of blasting them by gunpowder until they are reduced to a portable dimension. This however, is the practice almost universally resorted to in Scotland; and every where, I believe, throughout Britain, where this kind of improvement is carried on. In making the Highland roads also, where it is generally necessary to provide a quantity of stone for the masonry required in supporting the lower side of the road, in fortifying the upper bank, and in the construction of drains and bridges, it is usual to have recourse to such blocks, wherever the road itself is not carried through rocks in such a manner as to produce the necessary quantity of materials. In this case also, the process of blasting is adopted, as it necessarily is, whenever solid rocks are to be cut down or levelled. This process is both tedious and expensive, but the price, of course, varies with the wages of labour in different places. Where I am writing, it is now 2d. per inch, and, according to the dimensions or nature of the rock to be split, the mine varies from eighteen inches to two feet in depth, or, exclusive of the expense of gunpowder, the cost of this mine or blast hole will range from 3s. to 4s. It will be a very moderate calculation to estimate twelve inches for one mine, or 2s. for every large stone; and in most parts of the Highlands, or of Scotland in general, this is nearly a day's labour for a man, on account of the time expended in coming to the ground and in returning. To this expense, however, must be added, not only the price of the gunpowder, but that of sharpening the gads, which is considerable, and the other wear and tear of tools. I cannot here procure an exact estimate of these expenses, nor is it material, as it will easily be calculated by all those who have an interest in doing so, or have such work in hand. I need only add, that as, in many cases, the quantity of such stones, on ground otherwise fit for cultivation, is enormous, it is material to find out the means of diminishing an expense which may exceed the fee-simple of the land when cleared. The same reasoning applies to the Highland roads, which, from their expensive construction, trench so deeply on the funds provided for them, that VOL. II. NO. IV. 49 nothing remains to replace the accidents arising from torrents or other causes, or for the purposes of ordinary repairs. The contractor for a road from Loch Ewe to Gerloch, who resides at this place, finding it difficult to carry on his work at the contract price, has abandoned the process of blasting, and has had recourse to fire alone; and in this way he has now conducted his road for some miles with a great saving of both time and labour. Whether he has had any precursor, except Hannibal, in this practice, I know not, as I have not found it in use elsewhere in any part of Scotland; but he appears at any rate to have the merit of an original inventor, as he had heard neither of any predecessor nor rival in his art. In conducting the process, a fire of peat is made on the surface of the stone, and being then secured at the margin by stones and turf, it is kept in activity for five or six hours. At the beginning of his career, when the fire was extinguished, Mr Mackenzie was in the habit of throwing water on the rock, which was then found to open in different places, in such a manner as easily to admit a wedge or two, and thus to he split by a few blows of the sledge. But finding, in some situations, that it was difficult to procure water, and that the expense was thus materially increased, he abandoned this part of the process, and now finds that the stone, on cooling, is equally fissured, and equally admits the wedge. On examining the nature of the rocks submitted to this process, I doubted its efficacy, and was only convinced by witnessing the effects. They consisted of the roughest variety of gneiss; that kind which is composed, in a great degree, of compact feldspar, and of varieties equally tough and refractory, of hornblende rock or hornblende schist. Nor could any fissures be discovered in the blocks before the action of the fire, by which, if not produced, they were at least enlarged from a state previously invisible. As these are the only rocks which this part of the country affords, I cannot say whether the same effects would be found to take place in all, more particularly in granite. It is probable, however, that every rock is equally susceptible of being split by the same cause; as there are none in nature more compact and more apparently free from flaws, than those in which the process. succeeded at Loch Ewe. It is easy to understand how the effect is produced, as it is in glass, by the unequal expansion of the parts, even without the assistance of water; and it is equally easy to comprehend how a fire of only three or four feet in diameter is thus capable of acting on a stone of many tons in weight. It is probable that the quantity of fire, as well as its duration, must be made to vary with the dimensions of the block to be split; but, in all the instances which he had attempted, he had not at this time experienced a single failure, though a very considerable number of rocks had been removed in conducting the road for a space of about five miles. At the place in question, the peat was every where at hand, and required scarcely any expense of carriage; none other, in short, but that of being cut and cast in readiness for use whenever it was wanted. Wherever it may require a distant carriage in addition to that, it is evident that the charge will be augmented. In Highland road-making, peat is rarely far off; and, indeed, when it is not at hand, the same purpose may be served by the heath and turf, which is every where present, and of which a great quantity is necessarily removed in lining out the road. In clearing land in the Highlands, the same reasoning applies, as, either peat is seldom far distant, or the land itself furnishes brush-wood and weeds. These are often burnt for no other purpose than that of destroying them, and procuring the ashes and burnt earth attached, which are found to form an useful manure; while by making this use of them the same produce would be obtained in addition to the other advantages. In clearing land by this process, it would be necessary to form previous deposits of fuel in convenient parts of the field, that no impediment might take place during the process of firing, but that all the labour required for the several parts of the work, may, at one time, be directed to one object only. Thus the labour which, during one period, has been expended in distributing the fuel, will, in the second, be engaged in firing the stones; and, in the third, in splitting them by the wedge, when they will be ready for removal, either by the plug and gin, or by the more common proceedings. It will be seen that, in this case, the great saving of labour takes place in the firing, as one man can attend a considerable number of fires over a large space, and thus, in a single day, prepare an extensive tract for the hammer and wedge. Thus, it is calculated, that the firing and the previous labour of collecting fuel will not exceed the price of tools and gunpowder, and the comparison will then remain between the time or labour required to bore so many mines, or to split the blocks by the wedge. These are data easily ascertained |