Page:Popular Science Monthly Volume 5.djvu/393

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Volcanic Eruption in the Sandwich Islands.—A correspondent of the American Journal of Science writes that, until the past year, the great summit crater of Mauna Loa (Sandwich Islands) has for a number of years shown but few and feeble symptoms of activity. For a few days in August, 1872, there was a brilliant light in the crater, and again on the 6th and 7th of January, 1873, there were vivid demonstrations, which roused the attention of many witnesses. But it was not until the 20th of April, 1873, that a continuous exhibition of mountain pyrotechnics commenced. From that day down to the date of the letter (January 6, 1874), the action within the great caldron was incessant. Most of the time the boiling was vehement. "The scene was never more brilliant than a few nights ago. Sustained jets of molten rock were constantly rising 50 to 200 feet within the mural caldron, and the surgings, puffings, and roarings, have been heard low down the sides of the mountain, and, as some testify, as far as Reed's Ranch, probably fifteen miles." The most distinguishing feature of this eruption, however, was its duration. The eruption of 1855-'56 flowed fifteen months; but this rent the mountain laterally, and flowed longitudinally; whereas the present eruption has made no lateral vent, and found no outlet, so far as known. During all this time Kilauea was unequally active. The great depression of Kilauea, caused by the eruption of 1868, is fast filling up by repeated over-flows from the south lake, while all around that lake a vast mound is rising, whose summit is nearly as high as the southern rim of Kilauea, and it may soon over-look it.


Need of a New Chronology.—From the presence of the Egyptian Pyramids, Bayard Taylor thus writes to the New York Tribune: "As I rested in the shade, looking up to the gray pinnacles, so foreshortened by nearness that much of their actual height was lost, yet still indescribably huge, I could think of but one thing: we must have a new Chronology of Man. There, before me, the Usher-Mosaic reckoning was not only antedated, but a previous growth, of long, uncertain duration, was made evident. There, in stones scattered about the Desert, were inscriptions cut long before any tradition of Hebrew, Sanscrit, Phœnician, or Greek—clear, intelligible words, almost as legible to modern scholarship as those of living languages. This one long, unbroken stream of light into the remote Past lights up darker historic apparitions on all sides, and sweeps us, with or without our will, to a new and wonderful backward starting-point. Of course, the learned in all countries are familiar with all our recently acquired knowledge on this point; but is it not time to make it the property of the people everywhere—to discard the unmanly fear that one form of truth can ever harm any other form to reveal anew, through the grandeur of Man's slow development, the unspeakable grandeur of the Divine Soul by which it is directed?"


Life in an Attenuated Atmosphere.—M. Paul Bert, in a communication to the French Academy, details some further experiments made on himself, with reference to the effect of changes of barometric pressure on life. He entered his large apparatus of decompression, and the pressure was brought down to 450 millimetres (somewhat less than 18 inches of mercury); it was then maintained between this and 408 millimetres (16½ inches) for a little over an hour. These pressures correspond to heights of 13,448 and 16,728 feet. At 450 millimetres the author began to experience "mountain sickness"—a feeling of heaviness and weakness, nausea, fatigue of sight, general indifference, and laziness. Having lifted his right leg, it was thrown into convulsive trembling, which extended to the left, and lasted some minutes. The face was somewhat congested, and the temperature under the tongue increased. He also remarks that he was unable to whistle. The important point of these experiments, however, was this: he had taken with him a small vessel full of oxygen, and, when the pressure had reached 430 millimetres, he inhaled some of it. His pulse, which had risen from 62 to 84, immediately fell to 71,