RAINFALL. The fall of rain, in any district, constitutes a very important feature in the history of its climate, as it exercises a considerable influence upon the public health, the fertility of the soil, and the purity of the atmosphere. The position of Uckfield, near the centre of the Weald, is somewhat peculiar with respect to rainfall, as the amount is, doubtless, much influenced by the heavier falls which occur on the Forest Ridge to the north, and on the Downs to the south. The mean annual depth of rain at my observatory during the last twenty-eight years has been 29.38 inches. The following Tables will shew the details of this rainfall, and how great has been the variation in the several months, seasons, and years. The least amount of rainfall occurred in the year 1847, and the greatest in 1852; the total for the latter year approached nearly thrice that of the former. The average rainfall during Winter was 6.95; Spring, 5.81; Summer, 6.86; and Autumn, 9.71 inches. With reference to the fall of rain at Greenwich Observatory during the six years ending 1866, Mr. Glaisher remarks, that, generally speaking, the times of heaviest rainfall are In Winter, during the morning and afternoon hours. In Winter, during the six hours preceding, and six hours following, noon. In Spring, during the three hours following noon. In Summer, during the three hours following six p.m. In Autumn, during the six hours following noon, which are the most frequent of any in the year. It falls the least frequently— In Winter, during the three hours preceding midnight. In Spring, during the three hours from 6 to 9 p.m. In Summer, during the six hours before noon, which are the least frequent of any in the year. In Autumn, during the three hours preceding noon, and from 6 to 9 p.m. With respect to the average frequency of rain at the different hours thoughout the year, it is found that rainfall is most frequent between the hours of 2 and 3 p.m., and least frequent between the hours of 10 and II a.m. Also that rainfall is heavier by day than by night in spring, autumn, and winter; but in summer it is heavier by night than by day. Table (20) gives the instances of very heavy rains during each year-i.e., when the amount of rainfall during any twenty-four hours ending 9 a.m. has nearly amounted to, or exceeded, one inch and a quarter. Previous to the removal of the old bridge at Uckfield, in the year 1859, these heavy rains would generally produce a flood over the brook land between it and Buxted. Upon reference to the engraving, it will be seen how much the two heavy piers must have obstructed the current. Our heaviest rains occur in Autumn, which are very prejudicial to the ripening of fruit buds, the preparation of the soil for grain crops, and the crop of hops for the ensuing year. The effect of saturated soil upon the roots of hops is very injurious; and I have never known a heavy crop to be obtained, when, during the previous autumn, the rainfall has much exceeded the average. The next point of interest to the amount of rainfall is the number of wet days in the course of the year. Table (21) gives the monthly and annual number, and shews how slight a variation occurs, during a series of years, in the number of wet days for the several months. The least number will be found in June, and the greatest in October. The greatest monthly number of wet days occurred in Nov., 1843, and May, 1845, and the least in September, 1865. The greatest number in any year occurred in 1848, and the least in 1864. The greater or lesser number of wet days is no criterion of the amount of rainfall. Upwards of twelve inches more rain fell in 1852 than in 1848, and nearly six inches more fell in 1864 than in 1847. On the forest ridge to the north of the Weald, I am not aware that any rain guage has been kept, but as rain appears to fall more frequently in that direction than at Uckfield, the amount probably equals, if it does not exceed, that which falls along the course of the South Downs. Previous to the commencement of my register of rainfall in the year 1842 I am not aware that any observations were taken in this county, with the exception of those at Chichester; but at the present time nearly forty rain guages are at work, particulars of which may be found in Mr. Symon's "Annual Volume of British Rainfall for the Year 1870.” WIND. The tables respecting the direction of the wind are the results of observations taken twice daily,viz., at 9 a.m. and 9 p.m. The general direction of the wind will be found to vary considerably in the different months and years; thus The north wind numbered 12 days in 1863 and 41 days in 1846. The N. wind is most prevalent in November; N.E. in March and May; E. in April; S.E. in May; S. has never been the prevalent wind in any month; S.W. in January; W. in August; and N.W. in April and November. It is very remarkable that the S.W., one of our warmest winds, is the most prevalent wind during our coldest month. The W. is much more prevalent in this county than in the neighbourhood of London. inclined to believe that when the S.W. current is not very strong the western extremity of the Downs breaks its force, and sometimes alters its direction. On such occasions a S.W. wind would continue to blow along the coast, and a westerly breeze across the Weald. I am |