Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/785

Rh trachyte, amphiboliferous andesite and dolerite); (4) tuffs and tufaceous sandstones, with banks of limestone and marl; (5) banks of coral and breccia of coraliferous limestone, and recent volcanic products. The late origin of the coralliferous limestone is shown by the corals belonging to genera still existing in the Indian Ocean—Galaxea, Favia, Meandrina,Porites,and Astracopora and being specifically similar, though not identical. A remarkable feature is the stratification of the limestone.

Volcanic forces, as has been already implied, have had a great share in shaping the archipelago, and a large number of the mountains bear the stamp of their former activity. But those that still have the credit of being working volcanoes are comparatively few.

Monte Cagua (3910 feet), discovered by Claudio Montero on the north-eastern promontory of Luzon, appears to discharge smoke continually, and the Babuyanes group (to the north of Luzon) contains several orifices belonging to the same centre of eruption,—a regular volcano in Babuyan Claro, a solfatara in the Didica rocks, and a volcanic island thrown up in 1856. Of greater importance are the three burning mountains of southern Luzon—Taal, Albay, and Bulusan. Taal lies 45 miles almost due south of Manila. Being only 850 feet high, it is remarkable as one of the lowest volcanoes in the world. The present craters are situated in a small triangular island in the middle of Lake Bombon or Bongbong. A tradition exists (and has been accepted without question by many writers) that this lake, covering an area of 100 square miles, and having in the south and east a depth of 109 fathoms, was formed in 1700 on occasion of a terrible eruption, which undermined the whole mass of a gigantic mountain, 8000 or 9000 feet high; and, whether (for this is extremely doubtful) the event took place within historic times or not, the vast deposits of porous tuff in all the surrounding country appear to show that such a volcano must have existed. The water in the lake is now sweet, but tradition again asserts that it was at one time salt, possibly through direct communication with the sea. As it is exposed to strong evaporation and discharges into the sea by the Pansipit without being recruited by any considerable affluent, it is probably fed by subterranean sources. To the east of Lake Bombon stands the extinct volcano of Maquiling, at whose foot are the hot springs of Los Baños; and about 15 miles farther east is Majaijai (7020 feet), of which the last eruption was in 1730. Away in the south-east of Luzon there is quite a series of high volcanic cones,—Isarog, Iriga, Mazaraga, and Albay or Mayon. The last, one of the most active volcanoes in the archipelago, is extremely regular in form, rising gradually from a base about 50 miles in circuit. The first partial ascent was made by Esteban Solis in 1592, and the first complete ascent by Paton and Stewart, two young Scotchmen, in 1858. A terrible eruption on 1st February 1814 partially destroyed Camalig, Budiao, Albay, Guinobatan, and Daraga, and proved fatal to 12,000 persons, the matter thrown out forming vast deposits deep enough in some places near the mountain to bury the loftiest trees. A similar fate befell the same district during the eruptions that occurred between 20th July and 24th October 1867. On 31st October 1876 one of the terrible storms for which the Philippines are notorious burst on the mountain; the floods, pouring down the sides of Mayon and sweeping along with them the loose volcanic debris, brought destruction on Manilao, Camalig, Guinobatan, Ligao, Oas, Polangin, Libon, and other places, filling up the roads, breaking down the bridges, and completely ruining upwards of 6000 houses. During 1881 and 1882 the eruptive forces were again exceedingly active. Still farther to the south, in the very extremity of Luzon, stands the volcano of Bulusan, which, after being for a long time apparently extinct, began again to smoke in 1852. According to Jagor (Reisen, p. 66), it repeats in striking fashion the forms of Vesuvius, having two peaks,—in the west a bell-shaped dome, the eruption cone, and in the east a high ridge similar to Monte Somma, probably the remains of a great circular crater. As in Vesuvius, the present crater is in the centre of the extinct one. In the island of Negros, 150 miles south-south-west of Bulusan, there is the volcano of Malaspina or Canlaon (8190 feet); the island of Fuego probably takes its name from its volcanic phenomenon; and about 90 miles farther to the south-east a new volcano burst out in 1876 in the island of Camiguin (not to be confounded, as it sometimes is, with Camiguin off the north coast of Luzon), near the village of Catarman. In the great island of Mindanao we have the three volcanoes of Macaturing (Sugut, Tolloc, or Cottabató), inland from Illana Bay, and Apo and Sanguil (Sarangani or Butulan), both in the central Cordillera and the latter almost at its southern terminus. Though the last great eruption of Cottabató was in 1856, it is still active at intervals, and in 1871 the town of the same name was

partially destroyed by earthquakes. Apo, according to Schadenberg and Koch, has three summits, in the midst of which lies the great crater, now extinct and filled with water. Considerable energy is still displayed by the solfataras and boiling springs lower down.

It is difficult to say how these various volcanoes are related to each other; José Centeno suggests with considerable probability that they form two lines of activity, an eastern comprising Isarog, Albay, Bulusan, Camiguin, Apo, and Butulan, and a western Buguias (extinct), Arayat (extinct), Taal, Canlaon, Macaturing. Three only of the larger islands, it will be observed, contain actual centres of eruption, and some of the larger volcanoes appear to be in the later stages of their activity,—Albay generally discharging an incoherent form of lava, whilst Taal and others discharge nothing but ashes. Other phenomena usually associated with volcanic activity are common enough throughout the archipelago: there is a great deposit of sulphur in the middle of the island of Leyte; inflammable gas bursts out in the south of Panay; and there are hot springs at Buguias, at Los Baños or Maynit, already mentioned, at Pagsanghan, at San Luis or Maynit in Batangas, in the Taysan Mountains, at Tibi or Tivi, &c. At Los Baños there was a regular bathing establishment erected by the Franciscans in 1671; but it was burned down in 1727, and, though rebuilt by public subscription in 1880, may be said to be in a chronic state of decay. The Tibi springs, described in detail by Jagor (Reisen, pp. 114, 115), are remarkable for beautiful cones produced by the deposit of siliceous material. The water in some cases is hot enough to cook food. They are situated on the east coast of Luzon on Lagonoy Bay.

Earthquakes.—Earthquakes are sufficiently frequent and violent in the Philippines to affect the style adopted in the erection of buildings; in 1874, for instance, they were very numerous throughout the archipelago, and in Manila and the adjacent provinces shocks were felt daily for several weeks. The most violent earthquakes on record in the Philippines occurred in July 1880, when the destruction of property was immense, both in the capital and in other important towns of central Luzon.

Minerals.—Though hitherto little advantage has been taken of its existence, there appears to be in several of the islands a fair amount of mineral wealth. Two coal-fields are known to exist, one beginning in Caransan in the south of Luzon, and probably extending southwards across the Strait of San Bernardino to Catbalongan in Samar, and another occupying the Avestern slopes of Cebu and the eastern slopes of Negros, and thus probably passing under the Strait of Tañon. In the first basin there is a bed from 10 to 20 feet thick cropping out at Gatbo, which has given good results as a fuel for steamboats; in the second Centeno reports at least five beds of varying thickness and quality. The first discovery of the mineral was made in Cebu in 1827. Hitherto little success has attended the schemes of exploitation. Iron-ore of excellent purity occurs in various parts of Luzon, in Laguna, Bulacan, Pampanga, Camarines Norte, and notably in the Camachin Mountains between the Bulaon and the Garlan; but, with the exception of a few small foundries in Bulacan province, there are no iron-works in the country. In this department there was actually more activity a century ago. Copper-mines are worked at Mancayan, Suyuc, Bumucum, and Agbao in the province of Lepanto, by the Cantabro-Philippine Company, founded in 1862; and the heathen natives of that region (perhaps having learned the art from Chinese or Japanese strangers) appear to have long been accustomed to manufacture copper utensils for their own use and for sale in the Christian settlements. The ore at Mancayan contains upwards of 16 per cent. of copper, 24 of sulphur, 5 of antimony, and 5 of arsenic. For a short time after 1847 copper-mines were worked