Sir Charles Lyell, who has shown the power of existing causes with great ingenuity, estimates that on an average twenty eruptions take place annually in different parts of the world; and many must occur or have happened, even on the most extensive and awful scale, among people equally incapable of estimating their effects and of recording them. We should never have known the extent of the fearful eruption which took place in the island of Sumbawa, in 1815, but for the accident of Sir Stamford Raffles having been governor of Java at the time. It began on the 5th of April, and did not entirely cease till July. The ground was shaken through an area of 1000 miles in circumference; the tremors were felt in Java, the Moluccas, a great part of Celebes, Sumatra, and Borneo. The detonations were heard in Sumatra, at the distance of 970 geographical miles in a straight line; and at Ternate, 720 miles in the opposite direction. The most dreadful whirlwinds carried men and cattle into the air; and with the exception of 26 persons, the whole population of the island perished to the amount of 12,000. Ashes were carried 300 miles to Java in such quantities that the darkness during the day was more profound than ever had been witnessed in the most obscure night. The face of the country was changed by the streams of lava, and by the upheaving and sinking of the soil. The town of Tomboro was submerged, and water stood to the depth of 18 feet in places which had been dry land. Ships grounded where they had previously anchored, and others could hardly penetrate the mass of cinders which floated on the surface of the sea for several miles to the depth of two feet. A catastrophe similar to this, though of less magnitude, took place in the island of Bali in 1808, which was not heard of in Europe till years afterwards. The eruption of Coseguina in the Bay of Fonseca, which began on the 19th of January, 1835, and lasted many days, was even more dreadful and extensive in its effects than that of Sumbawa. The ashes during this eruption were carried by the upper current of the atmosphere as far north as Chiassa, which is upwards of 400 leagues to the windward of that volcano. Many volcanoes supposed to be extinct have all at once burst out with inconceivable violence. Witness Vesuvius, on historical record; and the volcano in the island of St. Vincent in our own days, whose crater was lined with large trees, and which had not been active in the memory of man. Vast tracts are of volcanic origin where volcanoes have ceased to exist for ages. Whence it may be inferred that in some places the subterraneous fires are in the highest state of activity, in some they are inert, and in others they appear to be extinct. Yet there are few countries that are not subject to earthquakes of greater or less intensity; the tremors are propagated like a sonorous undulation to such distances that it is impossible to say in what point they originate. In