68 



Report S.A.A. Advancement of Science. 



system during this period ? The severe drought of 1899-1901 was associ- 

 ated with an irregular pressure curve usually above normal, pointing to a 

 return of the system gradually to its mean path nearer Mauritius. Lastly, 

 during 1903 the rainfall abnormality curve showed no well marked waves 

 though there was a gradual decrease in the amplitude from September to 

 the end of the year, accompanied by a gradual rise in the pressure curve. 

 The mean monthly rainfall during 25 years has been tabulated, and 

 amounts to 48'36 inches for the year. Only II inches of this amount fall 

 from June to November inclusive ; 22 inches fall in January, February 

 and March. 



Appendix VII. 

 Natal Observatory, Durban. 



Monthly Mean Barometric Pressure, reduced to Sea-level, corrected to 

 32 F., derived from 9'' and 15'' readings. 



January... 



February 



March 



April 



May 



June 



July 



August ... 



September 



October 



November 



December 



1904. 



inches. 



29-976 

 30-002 

 •044 

 •066 

 •167 

 •201 

 274 

 -181 

 •190 

 -029 

 •024 

 -060 



Note. — The readings in 1899 were exceptional. The mean pressure for the 

 year was30-I29 ins. — the record for 33 years. The pressure in March is 

 noted as exceptionally high, but it was surpassed in March, 1901 and 

 1905. The readings in February and March point to an early establish- 

 ment of high pressure, which is probably attributable to the approach of 

 the Atlantic system across South Africa. 



