Mr. E.B. Elliot of Boston, in an interesting article upon the recent aurora, points out the simultaneous occurrence of the auroral display of February 19th, 1852, with the eruption of Mauna Loa,--the largest volcano in the world, situated on Hawaii, (one of the Sandwich Island group,)--on the 20th of February; on which occasion, the side of the mountain gave way about two-thirds of the distance from the base, giving passage to a magnificent stream of lava, five hundred feet deep and seven hundred broad. Again, on the 17th of December, 1857, between the hours of one and four in the morning, there occurred an aurora of unwonted magnificence. The first steamer arriving from Europe after that date brought the following intelligence, which is taken from one of the journals of the day:--"An earthquake took place on the night of the 17th, throughout the whole kingdom of Naples, but its effects were most severe in the towns of Salerno, Potenza, and Nola. At Salerno, the walls of the houses were rent from top to bottom. Numerous villages were half destroyed." Were these coincidences of extraordinary auroras with extraordinary commotions in the physical condition of our globe merely accidental? or are these phenomena due to a common cause? The latter supposition is not improbable, but the question can be fully settled only by further observations. Mr. Meriam, "the sage of Brooklyn," as the daily journals denominate him, considers the aurora as the result of earthquakes or volcanic eruptions. He also says:--"The auroral light sometimes is composed of threads, like the silken warp of a web; these sometimes become broken and fall to the earth, and possess exquisite softness and a silvery lustre, and I denominate them the products of the silkery of the skies. _I once obtained a small piece, which I preserved._" It is due to Mr. Meriam, as well as to the scientific world, to say, that he stands alone in his convictions with regard to the aurora, both in respect of the cause and the effect of the phenomenon. Having thus illustrated the effects of the aurora, let us now return to the discussion of its causes. The intimate and constant connection between the phenomena of the aurora borealis and terrestrial magnetism led Humboldt to class under the head of Magnetic Storms all disturbances in the equilibrium of the earth's magnetic forces. The presence of such storms is indicated by the oscillations of the magnetized needle, the disturbance of the currents upon the telegraph-wires, and the appearance of the aurora, of which these oscillations and disturbances are, as it were, the forerunners, and which itself puts an end to the storm,--as in electric storms the phenomenon of lightning announces that, the electrical equilibrium, temporarily disturbed, is now restored.