A HISTORY OF WORCESTERSHIRE a lower figure, although it is probable it made the temperature far less uniform. It is only at Birmingham that there are any recorded observations as to solar radiation, sunshine and wind. The solar radiation is ascertained by taking the maximum tempera- ture given by a blackened bulb thermometer in vacuo exposed to the direct rays of the sun. The figures given are for the twelve years ending December 31, 1899 — Solar radiation Date of greatest Solar radiation Date of greatest January . 937 21, 1898 July . . . 138-0 2, 1893 February 1007 23, 1897 August 133-0 12, 1898 March . . 117-3 26, 1897 September 130-0 7, 1898 April . . . 1257 21, 1893 October . . 113-9 5, 1896 May . . . 1326 31, 1892 November 97-9 2, 1894 June . . . 133-8 16, 1896 December 88-5 II, 1898 The amount of sunshine is measured by a Jordan's sunshine recorder, which is placed on the top of the monument, about 100 feet above the ground. It gives the following figures for the twelve years — Hours and minutes of sunshine for the months Hours and minutes of sunshine for the months Hours and minutes of sunshine for the months January . February March . April . . 35-29 55-22 91-15 1 1 2-3 May . June . July . August 143-19 146-23 130-53 127-51 September October . November December "3-39 69-30 36-36 32-57 As to the wind, the pressure is ascertained by Osier's anemometer. The pressure plate presents a surface to the wind of 2 feet superficial. Total velocity Extreme pressure Total velocity Extreme pressure in miles in lb. per sq. ft. in miles in lb. per sq. ft. January . 9,800 20-0 July . . 8,571 II-O February . 9.334 27-5 August . . 8,762 I2-0 March . 10,426 37-0 September . 8,142 15-0 April . . 9,014 17-0 October . 8,961 ly-o May . . 9,184 i8-o November . 9,435 19-0 June . 7,908 1 0-0 December . 10,221 24-0 The prevailing winds when they blow heaviest are south-west to west, in January, February, March and December. The easterly winds are of longer duration when they come, but do not equal the west or south-west either in velocity or pressure. 80
