62 



Report S.A.A. Advancement of Science, 



Appendix I. 



Provisional Chart of Isobars. 



FEBRUARY. 



Buchan. — His chart gives the isobars as lying SSWto NNE. The SE is nearly 

 29'86 ins., the North29'83. At Pretoria the pressure is 29'846ins. 



Jan. — His isobars lie NNE to SSW across Transvaal, 2977 on West and 

 2982 on East side. At Pretoria pressure is 2979 ins. 



Mar. — His isobars lie more SW to NE and pressure varies from 29'93 

 in SE to 29"88 in North. At Pretoria pressure is 29'9l ins. 



Ap. — His isobars lie from NW to SE across Transvaal, the southern ones 

 becoming nearly E to W (30"04). The Northern isobars are 

 parallel and regular (29"99 the extreme NE one). At Pretoria 

 pressure is 30025. 



