In some of the straits dividing the islands there are strong currents, rendering navigation of sailing vessels very difficult, notably in the San Bernadino Straits separating the Islands of Luzon and Samar, the roadstead of Yloilo between Panay and Guimarras Islands, and the passage between the south points of Cebu and Negros Islands. Most of the islets, if not indeed the whole Archipelago, are of volcanic origin. There are many volcanoes, two of them in frequent intermittent activity, viz. the Mayon, in the extreme east of Luzon Island, and the Taal Volcano, in the centre of Bombon Lake, 34 miles due south of Manila. Also in Negros Island the Canlauan Volcano--N. lat. 10 deg. 24'--is occasionally in visible eruption. In 1886 a portion of its crater subsided, accompanied by a tremendous noise and a slight ejection of lava. In the picturesque Island of Camiguin a volcano mountain suddenly arose from the plain in 1872. The _Mayon Volcano_ is in the north of the Province of Albay; hence it is popularly known as the Albay Volcano. Around its base there are several towns and villages, the chief being Albay, the capital of the province; Cagsaua (called Daraga) and Camaling on the one side, and Malinao, Tobaco, etc., on the side facing the east coast. The earliest eruption recorded is that of 1616, mentioned by Spilbergen. In 1769 there was a serious eruption, which destroyed the towns of Cagsaua and Malinao, besides several villages, and devastated property within a radius of 20 miles. Lava and ashes were thrown out incessantly during two months, and cataracts of water were formed. In 1811 loud subterranean noises were heard proceeding from the volcano, which caused the inhabitants around to fear an early renewal of its activity, but their misfortune was postponed. On February 1, 1814, [6] it burst with terrible violence. Cagsaua, Badiao, and three other towns were totally demolished. Stones and ashes were ejected in all directions. The inhabitants fled to caves to shelter themselves. So sudden was the occurrence, that many natives were overtaken by the volcanic projectiles and a few by lava streams. In Cagsaua nearly all property was lost. Father Aragoneses estimates that 2,200 persons were killed, besides many being wounded. Another eruption, remarkable for its duration, took place in 1881-82, and again in the spring of 1887; but only a small quantity of ashes was thrown out, and did very little or no damage to the property in the surrounding towns and villages. The eruption of July 9, 1888, severely damaged the towns of Libog and Legaspi; plantations were destroyed in the villages of Bigaa and Bonco; several houses were fired, others had the roofs crushed in; a great many domestic animals were killed; fifteen natives lost their lives, and the loss of live-stock (buffaloes and oxen) was estimated at 500. The ejection of lava and ashes and stones from the crater continued for one night, which was illuminated by a column of fire.