Abstract
LONDON. Royal Meteorological Society, June 19.—Mr. W. H. Dines, president, in the chair.—A paper by Mr. FT. Helm Clayton, of the Blue Hill Observatory, U.S.A., on the eclipse cyclone, the diurnal cyclones and the cyclones and anti-cyclones of temperate latitudes, was read by the secretary. The author has discussed the meteorological observations made along the path of the total solar eclipse in the United States on May 28, 1900, and also those made during three previous eclipses. He finds that a cyclone follows in the wake of the eclipe—though the changes are very minute and feeble—the fall of temperature developing a cold-air cyclone in an astonishingly short time, with all the peculiar circulation of winds and distribution of pressure which constitute such a cyclone.—A paper, by Mr. F. Napier Denison, of Victoria, British Columbia, on the seismograph as a sensitive barometer, was also read by the secretary. A Milne seismograph was installed in 1898 at the Meteorological Office, Victoria, B.C., and the author has since that time compared its movements with the changes of atmospheric pressure recorded by his “a rograph.” He finds that when the barometric pressure is high over the Pacific slope from British Columbia southward to California, while off the Pacific coast the barometer is comparatively low, the horizontal pendulum of the seismograph tends to move towards the eastward. This movement appears to be due to a distortion of the earth's surface, caused by the heavier air over the Pacific slope depressing the underlying land surface below its normal position, while, on the other hand, the comparatively light air over the adjacent ocean tends to allow the sea and earth beneath to rise above its normal level. It has been found that when an extensive storm area is approaching from the westward, and often eighteen to twenty-four hours before the local barometer begins to fall, the pendulum of the seismograph swings steadily to the eastward, completely masking any diurnal fluctuations that might have existed, as the storm area approaches, and in the event of it being followed by an important high area, the pendulum will begin to swing towards the westward before it is possible to ascertain this area's position on the current weather charts.
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Societies and Academies . Nature 64, 271–272 (1901). https://doi.org/10.1038/064271a0
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DOI: https://doi.org/10.1038/064271a0