Earthquakes are as frequent in these islands as on the mainland, and it does not appear by any means improbable, from the conic formation of most of the mountains, and their scorified appearance, that they are the produce of some dreadful internal convulsion, which has disrupted them from the adjacent continent, on which is the lofty snow-capped summit of the great Corcobado, and several active volcanoes; the range of the Cordillera approaching close to the coast in these latitudes. In 1737, the Archipelago suffered very much from the effects of an earthquake, and the islands of the Guaytecas group to the south, were covered with ashes which destroyed the vegetation for thirteen years. The continent opposite to the northern extremity of Chiloe, has some Spanish settlements in the country of the Canches and Huilliches, small but independent tribes; these settlements are said to be three in number, of which _Fort Maullin_, opposite to Chaco Bay in Chiloe is the chief, and the Spaniards are engaged in forming communications from this settlement to Valdivia; as the sea is rendered almost innavigable during the winter by the frequent and dreadful storms. Pedro de Agueros, gives the names of twenty-four islands on the east of the Great Chiloe, which are inhabited, but as so little is known concerning this group, and as several contradictory statements have been made about them, the mere names are uninteresting. The capital is _Castro_, in 42° 40' south latitude, on the eastern shore of the island of Chiloe, upon an arm of the sea, and was founded in 1566, by Don Martin Ruiz de Gamboa. The houses, as is the case with all the rest in the province, are of wood, and are inhabited by about 150 persons; it has a parish church, a convent of Franciscans, and another of Mercedarii, in which only two or three monks reside. This city was overthrown by an earthquake soon after its foundation, since which it has never been in a flourishing state; it is 180 miles south of Valdivia. The other towns are the port of _Chacao_ or _Chaco_, in the middle of the north coast of Chiloe, and opposite to Port Maullin, which has a tolerable anchorage, but is difficult of access. _San Carlos_ is on the Bahia del Rey, and was built In 1767, on account of the difficulties attending the entrance to Chaco. It is in 41° 57' south latitude, and 73° 58' west longitude, and is the most populous and flourishing town in the province, containing 1100 inhabitants. The harbour is good, but subject to tremendous squalls and hurricanes; and the town is fortified, and has a regular garrison; and from the advantages of its harbour, the governor and council always reside at San Carlos. The other islands have each one settlement and a missionary church on them, excepting _Quinchuan_, which has six; _Lemui_ and _Llachi_, each four, and _Calbuco_ three, but none of any material consequence.