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    LONDON. Royal Meteorological Society, November 16.—I. D. Margary: The Marsham phenological record in Norfolk, 1736–1925, and some others. A remarkable phenological record kept by five generations of one family at Hevingham near Norwich is presented. The observations include the dates of leafing of 13 common trees, flowering of snowdrop, hawthorn, etc., and the movements of 8 migrant and other birds. The mean date for a group of seven of the plant events covering the period January-May has been worked out for each year. The annual variations are closely related to temperature and show a very definite periodicity, averaging twelve years between unusually backward springs or early springs. Recent extreme years are: early, 1912, 1921; late, 1908, 1917. The intervals have recently been shorter than the average. Comparing the plant dates in the eighteenth and twentieth centuries (taking averages for the thirty-five year periods 1751–85 and 1891–1925) of the 16 plants, 10 were earlier in the recent period, 3 were unchanged, and 3 later, possibly an indication of an earlier tendency in recent springs. Migrant birds seem independent of these conditions. The swallow's date of arrival is definitely getting later (the average for the thirty-five years 1891–1925 being eight days later than for 1751-85), in contrast to that of the cuckoo, which has on the average kept a constant date throughout the period.—C. D. Stewart: Experiments in the shielding of rain gauges. The chief difficulty met with in the measurement of rainfall is the effect of wind in decreasing the catch of a gauge owing to the eddies set up by its projecting parts. At Valencia Observatory it has been found that protection is afforded in varying degrees by buildings, the Nipher shield and pits.—Harold Jeffreys: On the dynamics of geostrophic winds. All problems of the motions of the atmosphere produced by temperature changes of large horizontal extent can be reduced to closely related problems of tides in an ocean of uniform depth, and, in the absence of friction, they can in general be solved by known methods. The theory is applied to the annual variation of pressure in Central Asia, and gives fair quantitative agreement. When applied to the general circulation, however, it gives easterly winds everywhere. Friction would considerably alter this result; indeed a steady circulation is impossible when friction is present. The only dynamically admissible types of motion with friction involve westerly circulations around the poles and systems of cyclones the height of which is comparable with that of the tropopause.

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