Page:Popular Science Monthly Volume 7.djvu/758

738 "from morning till night, there was never heard so violent a storm of thunder and lightning, as if heaven and earth had been mixing together;" the town-house and several other houses were destroyed by it. The peasants on the neighboring hills observed that this lightning had burnt the vines so that no crop could be expected for the season.

The earthquake of London, 1749, also exhibited strong symptoms of electric action. The year abounded with thunder and lightning, coruscations frequently appeared in the air, and the aurora removed to the south, showing upon two occasions unusual colors. Dr. Stephen Hales heard a rushing in his house which ended in an explosion in the air as from a small cannon, and attributed it to the escape of the fluid by the steeple of the church of St. Martin's-in-the-Fields, adjoining. The Rev. J, H. Murray refers to the electrical disturbances on the east coast of South America, contemporaneous with the great earthquakes on the west coast in 1868, and considers them related. He describes one storm, just at the time of the earthquake, as giving "an idea of what the bombardment of Sevastopol must have been like."

The phenomena of seaquake are of a similar character. We have ourselves seen electric clouds thrown into auroral forms contemporaneously with the disturbance of the sea at another locality.

Examples might be extensively multiplied, but the above would seem sufficient to show that a leading cause of earthquake is electric action, and that volcanoes sometimes produce the same by direct convulsion, and at others by disturbing the electric equilibrium of a locality.—English Mechanic.



HE large island of Madagascar has of late excited a special interest among the lovers of natural history; the richness of its soil has been acknowledged, and the character of its vegetation and of its animals classified. During the present century, Europeans have chiefly visited the northern part of the island, and expressed in glowing language their admiration of its shores. The bay of Diego-Suarez, which is situated in the most northerly point of the island, is spoken of as one of the wonders of the world, and that of Passandava most enchanting. This, however, is not a fair picture of the whole; like other islands, it presents very striking contrasts. A recent traveler, M, E. Blanchard, who has visited certain parts of the island, chiefly to explore its mineral resources, describes in his book ("L'Île de Madagascar," J. Claye, imprimeur) the great chain of mountains and the 