Page:Palestine Exploration Fund - Quarterly Statement for 1894.djvu/62

42 next, that up to 1878 no fall of rain had reached 30 inches, the nearest approach being 29·75 inches in 1874; but on the diagram in eight years, viz., 1878, 1880, 1883, 1886, 1888, 1890, 1891, and 1892, the points are all well above 30 inches. It is remarkable that the largest fall of all, in 1888, should be followed in 1889 by one so small as 13·56 inches, being, in fact, the lowest but one in the 32 years.

By taking the means of the annual falls in two equal periods of 16 years, the first in the years 1861 to 1876, the mean is 22·26, and in the second, in the years 1877 to 1892, the mean is 28·20; therefore, the mean annual fall in the second half of the series is 5·94 inches greater than in the first half. This is very remarkable.

By comparing the average rainfall for each month, as shown in the last column of Table I, with the monthly fall of the same month in every year it will be seen that in every month, for three, four, or five successive years, the fall has been either above or below the mean; and—

In January in 16 years the fall was above and in 16 years below the mean.

In February in 13 years the fall was above and in 19 years below the mean.

In March in 13 years the fall was above and in 19 years below the mean.

In April in 13 years the fall was above and in 19 years below the mean.

In October in 7 years the fall was above and in 25 years below the mean.

In November in 13 years the fall was above and in 19 years below the mean.

In December in 15 years the fall was above and in 17 years below the mean.

In January of those above the mean there were four successive years, viz., 1861, 1862, 1863, and 1864, and two groups of three each, in 1885, 1886, and 1887, and 1890, 1891, and 1892. Of those below the mean there were two groups of four each, viz., to 1873 and 1879 to 1882.

In February above the mean there was only one group of three, in the years 1872, 1873, and 1874; of those below the mean there were three groups of three and one of four, viz., in the years 1862, and 1864; 1869, 1870, and 1871; 1879, 1880, and 1881, and 1887, 1888, 1889, and 1890.

In March of those above the mean there were two groups, one of three and one of five, viz., in the years 1879, 1880, and 1881, and 1883 to 1887. Of those below the mean there were three groups, of six, three, and five years, viz., 1864 to 1869, 1876 to 1878, and to 1892.

In April above the mean there were two groups, one of four and one of three years, viz., 1867 to 1870, and 1880 to 1882; below the