78 



Report S.A.A. Advancement of Science. 



towards the E across any given place, the wind in advance of its 

 centre blows from the equator, following its centre towards the 

 equator. These and similar facts learnt from observation form the 

 basis of weather-prediction. 



Eight diagrams giving t>arometer curves made up from the 

 morning observation at the Cape, Durban, and Johannesburg show the 

 progressive movement of barometer disturbances from W to E, so that 

 on the average, the changes take place ^6 hours later at Durban and 

 Johannesburg than they do at the Cape. 



Diagram 1.— (Upper half), 21st May— 5th June, 1905. 



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Mi^. 



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Diagram 2.— (Lower Half), 21st May— 5th June, 1905. 

 (Cape Advanced 36 hours). 



