WHOLE VOL. NOTES. AFRICA 5 



fall, are not strictly comparable. The station-level pressure 

 at Chukwani is 0.4 mb. lower than at the site of the older 

 station in the town. In order to obtain pressure at mean 

 sea level, 2.4 mb. should be added to the station-level 

 pressure. 



Data of pressure and rainfall of the Town Station were furnished 

 by the India Meteorological Office for the interval January 

 193 1 to March 1932 and are published on the form headed 

 Zanzibar (Town Station) which is a continuation of the 

 data published in the previous volumes. The temperatures 

 for the Town Station from 192 1 to 1936 were obtained from 

 other official sources. By comparison of the two sets of data, 

 differences may be found for correcting one to the other. 



The following smoothed values when added to the Chukwani 

 mean temperatures bring them approximately to the mean 

 temperature obtained at the Town Station (excepting No- 

 vember 1 931) : 



EGYPT 

 ALEXANDRIA (KOM EL NADORA) 



Authority. 



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

 Instruments. 



Barometer: Fuess Portable No. 1439, index correction — o.i 

 mm., was withdrawn in December 1934 and replaced by 

 Fuess Portable No. 105625, index correction +0.2 mm. 



Thermometers: New screen installed August 1935. A compari- 

 son over 2 years was made between the two screens. The 

 corrections for temperature so found to reduce these to the 

 same bases were very small, and none are applied. The cor- 

 rections to reduce the means of (8''+i4'' + 20*' + Min.) to 

 mean of day are unaltered. 



Rain gage: Withdrawn and replaced in August 1935 by a similar 

 gage at a height of i m. above ground. Previous gage was 

 2 m. above ground. 



HELWAN 

 Authority. 



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



