« السابقةمتابعة »
owing to its progressive lateral contraction, as is seen more markedly in
2. The opening of fissures and evacuation through them of black fluid matter. The spasmodic expansion and contraction of fissures continued after the shock.
3. The disruption of portions of mountains or landslips.
4. The elevation of tracts of land.
5. The greater violence of earthquakes on hills. This was observed at Pinang in 1843. Marsden remarks that houses situated on a low sandy soil are least affected, and those which stand on distinct hills suffer most from the shocks.
6. The connection between earthquakes and the condition of the atmosphere. To what is stated by Lieut. Crooke respecting the great drought which preceded the earthquake at Jambi, the following extract from Marsden relative to Sumatran earthquakes in general may be added: Earthquakes have been remarked by some to happen usually on sudden changes of weather, and particularly after violent heats; but I do not vouch this upon my own experience, which has been pretty ample." The earthquake of 1843 occurred during one of the longest and severest droughts that had ever happened in Pinang. drought, which was attended with oppressive heat and occasional hot winds, never before experienced within the memory of the residents, appears to have extended over the northern part of Sumatra.
When the foregoing paper was written I had not seen the talented and eleborate memoir on Indian Earthquakes by Lieutenant R. B. Smith, which I received by the Hooghly. The portions at which I have had time to glance suffice to show that it contains a mine of wealth. The above notices of Malayan earthquakes, however meagre, may serve to connect his researches with the Indian Archipelago, respecting the general geology and recent volcanic disturbances of which I am collecting information. Meantime the subjoined account which has been furnished me by my brother, abridged from the official report of the Alcalde Mayor of the province of Cagayan in the Island of Luzon, of an earthquake attended by the subsidence of two hills and by a violent hurricane which occurred there on the night between the 7th and 8th October last, may prove interesting. It will appear in the
Singapore Free Press, but I presume that will form no objection to its being put on record in the more permanent pages of the Journal.
"The Casa Real of LALLO, a brick-building, and one of the most solid edifices in the province, was destroyed. The rector's house was destroyed, and the roof of the Church suffered much damage, and many other of the public edifices were more or less injured. The Tribunal stood it out well, and will only require a new roof. All the wooden houses were levelled with the ground. None of the attap houses escaped, and the greater part were blown over with many of their unhappy owners in them, and their little stores of paddy. The people notwithstanding, had been since occupied in repairing the serious injuries which the Renta de Tabacos had suffered, and the wages, which were paid daily, served as some consolation to them in the midst of so much misfortune. Five persons are reckoned to have been killed and 11 wounded. In CALAMANIUGAN the Church and rector's house were entirely destroyed, and the priest was living in the Royal Tribunal which had escaped injury, and in which he had erected an altar. The wooden houses suffered more than those of Lallo. The attap houses were all destroyed. The people experienced the misfortune of being caught by the hurricane with the greater part of their grain still on the ground, the whole of which was destroyed. Eleven persons were killed, and 20 seriously injured. At APARRO the majority of the houses in the district are of wood which were mostly all destroyed. The Royal Tribunal, a new and solid building, was overthrown-the rector's house destroyed and the Church much injured. Nearly all the wooden houses were destroyed, and none of the attap ones escaped, the greater part going to block up the river or into the sea, which rose into the village and contributed to make the night more frightful, and to augment the number of victims, who amounted to 27 killed and 53 wounded. All the harvest that had been gathered in perished, being carried into the sea with the houses. The destruction of buffaloes, horses, cows, and other property was excessive. In BUGUEY nearly all houses and buildings were destroyed :-one man killed. The Convent of ABULOG was entirely demolished, the Church lost its roof and belfry, and nearly all the houses were levelled with the ground::-8 persons were killed. To the north of this village, at the distance of 6 miles, there is a high hill on the top of which dwelt a number of natives who pay allegiance
to Her Majesty. These people relate that on the evening preceding the hurricane they felt great and frequent tremblings of the earth,that at nightfall they began to hear in the midst of it a frightful noise which impelled them to abandon their abode, and fly, full of fear, to a creek for shelter from the fury of the tempest which was increasing :on the ceasing of the storm, on the morning of the 8th, they returned to their dwelling, when they found that it and the hill on which it stood had sunk,-there appearing in its place a large lake of black water, of a fetid odour, and smoking. In PAMPLONA the Churches and Tribunal were destroyed, as well as the rest of the houses, with the exception of the Church of the division of Masi, which being of very solid construction, escaped with trifling injury; 5 persons were killed. At the entrance of the river of this village there was a hill sixty feet high separating the sea from the river, which having disappeared, the two waters are now joined and a wide and practicable passage opened. Five victims are reported. Within the boundaries of all these districts nature presents a most sombre picture, not a single green tree is to be seen, the thickest trunks alone remaining, and these as if only left at last to show that vegetation had ceased; which is no doubt owing to the great quantity of electricity with which the atmosphere was charged during the hurricane."
(To be continued.)
On the Refinage, on a large scale, by means of Nitre, of brittle or understandard Silver, for coinage purposes; and on a ready mode of approximative assaying of silver, by W. B. O'SHAUGHNESSY, M. D. and F. R. S., Co-Secy. Asiatic Society of Bengal.
Although the subject of the refinage of silver for coinage purposes may appear of too special and technical a character to warrant my affording to it any portion of the pages of this Journal, it still presents some collateral points of general interest. It affords an opportunity too of conveying in a simple and intelligible form a few observations regarding our silver standard and the approximative testing of silver coin and bullion, which may prove useful to some of the readers of this Journal who have to manage bullion transactions with native states.
The East India Company's new rupee is by law composed of 11 parts by weight of pure silver and 1 of copper. A pound of this alloy is divided into 12 ounces, each ounce into 20 penny weights. In the receipt of bullion tendered at the mints, the alloy of 11-12ths is taken as standard, and according to the number of half penny weights of pure silver, above or below eleven ounces, or 220 dwts. the bullion is on assay reported better or worse than standard. The composition of a few of the most remarkable varieties of bullion and coin received at the Calcutta mint will illustrate this statement.
These few instances are sufficient to exemplify the practical range of proportion in the silver and alloy of the bullion usually presented. By the mint rules a charge for refinage is levied on all such bullion, which is alloyed to a greater extent than 26 parts or penny weights in 240. technically 6" worse" than standard.
In alloys however of silver and copper only, it is generally found that however large the proportion of copper, the bullion does not require refinage for coinage purposes, if mixed with the requisite quantity of pure silver, or superior silver alloyed with copper only. Thus Dollars and Five Franc pieces may be used for alligation without risk of rendering the resulting ingots unmanageable in the subsequent stages of coinage. But if the bullion, whether worse or better than standard contains lead, tin, brass or sulphur in a larger proportion than two dwts. in the pound, it affords ingots which generally prove brittle in the course of manipulation, or give a mixture of uncertain fineness and unfit to be coined. To illustrate this I may mention that I have fre
quently known Sycee silver at 16 Br. alloyed with 24 copper, to yield bars as brittle as slate or cast iron; and these when assayed to prove 2 or even 3 dwts. better than standard. This proceeds from the presence of lead or sulphur in the Sycee silver, part of which burning off leaves the resulting mass richer in silver than before, but brittle from the small portion of lead which remains. On the other hand I have still more frequently seen alloys of silver and copper, 50 to 80 worse than stand ard, affording with the due proportion of richer silver, a perfectly malleable and standard metal.
The object of refinages for the mint is therefore usually to remove the lead, tin, zinc or sulphur and to leave the silver and copper or occasionally, when pure or rich silver is not available, to bring up inferior alloys to standard or even superior fineness.
The process followed by the native refiners in the bazar is that of cupellation, and is performed by them with great success and economy. They use for the cupel a mixture of one part by weight of recently burned lime, sifted but unslaked, and two parts by weight of chaff ashes. With this they make a basin like mass, usually eighteen inches in diameter below and 4 to 6 inches deep. This they moisten well with water and beat with the hands into firm consistence. Pieces of brick are placed round the sloping sides to give support, and two pairs of bellows are arranged so that by their alternate use a constant blast of air is kept up during the process.
While still wet the basin is charged with charcoal and an active fire kindled, the silver is then introduced and lead added till all is melted and red hot. Two large logs of firewood are then placed over the charcoal so as to form a dome to the heap, and at the interstices torchlike pieces of wood are continually introduced, so that a powerful flame is reverberated from the blazing dome above.
By this manipulation the lead is oxidized, and the oxyde of lead (litharge) formed is absorbed with the oxides of copper, and other base metals usually present, by the porous mixture of lime and ashes. None of the litharge is removed by skimming. In refining 2500 tola wt.* from 16"worse" they use 1200 tolas of lead, and the operation is completed in less than 3 hours, yielding a cake of silver 16 to 17 dwt. "better" than standard. The bazar refiners contract to return all the silver according The tola is 180 Troy grains. 32 tolas one Troy pound.