AnnualReport-1931 — Page 217

-F4-

Factor for converting the actual run of the Beckley Anemograph cups to velocities recorded by the Dines Pressure

Tube Anemograph.

Factor (Dines Beckley).

÷

Month.

Mean 1910-1930.

1931.

January,

1.96

2.08

February,

2'00

March,

2:06

2.08 2.16

April,.

2.09

2-17

May,

2.19

2.20

June,

2'12

215

July,

2.24

2 14

August,

2.23

2:28

September,

2.21

2.29

October,.

2013

2.23

November,

2.03

2.19

December,..

195

2.20

Year.........

210

2.18

III.--METEOROLOGICAL OBSERVATIONS AT THE OBSERVATORY.

9. Automatic records of the temperature of the air and evaporation were obtained with a Richard dry and wet-bulb thermograph, and 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 Nakamura Pluviograph and the amount of sunshine by two Campbell-Stokes universal sunshine recorders. Eye observations of barometric pressure, temperature of the air and of evaporation and the amount of cloud are made at each hour of Hong Kong Standard Time, and of terrestrial radiation. at midnight and at 6 a.m. (from 1930, January 1). The character and direction of motion of the clouds are observed every three hours. Daily readings are taken of self-registering maximum and minimum thermometers. Observations of pilot balloons are made with a Watts 14 inch "Coudé" theodolite at about 9h. a.m. and 3h. p.m., except when the base of the clouds is lower than Victoria Peak (1800 ft.)

10. Principal features of the Weather in 1931:-The principal features of the weather in 1981 were:-

(a) Typhoons passing near the Observatory on August

1, August 17 and September 2, respectively.