F 2
Thermometers.—All thermometers in use were compared with the Kew Standard in winter and summer.
The following table shows the results of comparisons between the Kew Standard purchased in 1884 and a Griffin Standard of Jena Normal Glass purchased in 1914. When compared with the National Physical Laboratory Standard, in April 1914, this thermometer required a correction of 0°-09F., which has been duly applied :-
Date. Kew Standard 647 Griffin 29996 (corrected). K-G 1914 July 2, 81.82 81.72 +0.10 1915 January 19, 60.00 59.86 +0.14 1915 September 29, 90.00 89.93 +0.07 1916 January 12, 55.00 54.95 +0.05 1916 September 1, 80.00 79.88 +0.12 1917 January 16, 54.60 54.48 +0.12 1917 January 17, 49.41 49.24 +0.17The results indicate that the Kew Standard No. 647 reads 0.11 too high; a very small change in thirty years.
III.—METEOROLOGICAL OBSERVATIONS AT THE OBSERVATORY.
Continuous photographic records showing the variations of barometric pressure were obtained with the Kew barograph, and automatic records of the direction and velocity of the wind with a Beckley and a Dines-Baxendell anemograph, modified as described in the Report for 1912. The amount of rain is recorded automatically by a Beckley and a Nakamura pluviograph, the amount of sunshine by a Campbell-Stokes universal sunshine recorder, and the relative humidity of the air by a small Richard hair hygrograph.
Eye observations of barometric pressure, temperature of the air, and of evaporation, were made at each hour of Hongkong Standard time. The character and direction of motion of the clouds were observed every three hours. Daily readings were taken of self-registering maximum and minimum thermometers.
Principal Features of the Weather in 1916.—The principal features of the weather in 1916 were the large departures from normal wind velocity in the different months, and the heavy rains from May 31 to June 13, when 306.75 inches fell, followed by a drought from October 25 to the end of the year, when only 0.125 of rain fell.
Barometric pressure was considerably below normal in February and June, and considerably above normal in July. The mean pressure for the year was 29.832, as against 29.836 in 1915 and 29.844 for the past 33 years.
The highest pressure was 30.332, on January 11, as against 30.375 in 1915 and 30.509 for the past 33 years. The lowest pressure was 29.304, on August 11, as against 29.354 in 1915 and 28.735 for the past 33 years.