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ON THE FALL OF RAIN AT JERUSALEM IN THE 32 YEARS FROM 1861 to 1892.
By James Glaisher, F.R.S.
The series of daily observations of rain was begun by Dr. Chaplin in the year 18 1, and was continued by him for the long period of 22 years till the end of 1882: they have since 1883 been continued under the auspices of the Palestine Exploration Fund.
The rain gauge used during the first six years was a float gauge by Newman, and since then a certified 8-inch gauge by Negretti and Zambra. During four years the gauges were placed side by side; the float gauge registered during these four years 88·83 inches, and Negretti and Zambra's gauge 93·25 inches, and the readings by Newman's gauge have been corrected so as to give results in accordance with the 8-inch gauge.
Dr. Chaplin says the position of the gauges was in a garden within the city, about 2,500 feet above the level of the Mediterranean, open on all sides, the houses which bound it on the south and west, being too far removed to influence the fall of rain on the pluviometer.
The results of the observations during the 22 years ending in 1882 have been discussed by Dr. Chaplin in seasons, and the results were published in the Quarterly Statement of the Palestine Exploration Fund for January, 1883.
The observations since 1883 have all been made by the 8-inch gauge and in the same position as that adopted by Dr. Chaplin.
Table I shows the fall of rain in every month during the 32 years ending with 1892.
In looking over the table the first thing noticeable is the very great difference in every month of the rainy season, between the falls in the same month in different years; for instance, in January the fall in the year 1873 was 0·13 inch, whilst in 1878 it was 13·39 inches.
Table II (see next page) shows the three heaviest and the three lightest falls of rain in every month excepting June, July, and August in the 32 years:—
