WHOLE VOL. NOTES. AFRICA 9 



Instrument: A barograph was in use controlled by the following 



barometer : Fuess Syphon 430, index error correction, 



0.0 mm. 

 Hours: The values are the means of 24 hourly readings from 



the barograph controlled by eye observations at 8 h , 14 11 , 



and 20 h . 

 Notes: The readings are at normal gravity (Lat. 45°) and station 



level, a correction of — 1.00 mm having been applied to the 



eye observations. 

 Temperature. 



Exposure: There has been no change of exposure. 



Hours: The values are from the dry -bulb observations and the 



minimum thermometer, the mean being calculated according 



to the following formula : 



-](8 h +i4 h + 20 h -|-Min.) 



and reduced to the true means of 24 hours by applying the 



following corrections : 



Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

 °C. +0.8 +0.8 +0.8 +0.8 + 0.~7 +0.7 +0.0 +0.5 +0.5 +0.6 +0.6 +0.7 



JOHANNESBURG, SOUTH AFRICA 



Authority. 



Meteorological Office, Department of Irrigation, Pretoria, Union 



of South Africa. 

 Pressure. 



Site: The observations were taken at the Observatory ; the height 



of the barometer cistern above Mean Sea Level was 5925 ft. 



throughout the period. 

 Hours: The hour of observation was 6i h Greenwich mean time 



throughout the period. 

 Notes: All values have been corrected to normal gravity (Lat. 



45°). 



Temperature. 



Site: As for Pressure. 



Mean: The standard adopted is the mean between the mean 



daily maximum and the mean daily minimum. 

 Precipitation. 



Site: The observations were taken at Joubert Park; the height 



above Mean Sea Level was 5750 ft. 



KHARTOUM, ANGLO-EGYPTIAN SUDAN 



Authority. 



Physical Department. Ministry of Public Works, Cairo, Egypt. 



