Meteorological Notes

Abstract

THE Report on the Meteorology of India in 1885, being the eleventh year of the series, has just been published, and contains an immense mass of valuable information. The accumulation of Indian statistics during the last ten years may be best shown by a comparison of the following figures:— The number of stations at which the mean temperature is recorded has increased from 51 to 127, and the rainfall stations from 134 to 471. From this huge volume of 516 large quarto pages we can only note here a very few general remarks. Considerable attention is paid to solar radiation, the chief feature of which is found to be that the maximum intensity generally occurs during the winter half of the year (October to March), when the sun is in southern declination, and the thickness of the absorbing atmosphere traversed by the sun's rays is at a maximum. This is said to be apparently due to the fact that over a large part of India the atmosphere is most cloudy in the summer and autumn months. It would appear from the mean result of the sun-thermometer readings in all parts of India that the average intensity of solar heat had reached a minimum in 1884, and in 1885 underwent an appreciable increase. The duration of bright sunshine is now regularly recorded at four stations, and Mr. Blanford considers that the sunshine-recorder promises to be even more important than the sun-thermometer, since the duration of sunshine is a more direct measure of the amount of solar heat reaching the earth's surface than the registry of its mean maximum intensity. Anemometers are in use at nearly all the stations, and fourteen of them are large anemographs of the Kew pattern. The resultant direction of the winds is, however, computed by Lambert's old formula, which is based on the assumption that the force of all winds is equal, an assumption which is obviously often very misleading. The work is accompanied by maps showing the positions of the meteorological observatories and the mean distribution of temperature, pressure, and wind.