90 



Report S.A.A. Advancement of Science. 



For the purposes of weather prediction in the Transvaal, our 

 material, though insufficient, is not too bad. We cannot be sure of 

 depressions approaching the Colony from the NE, as we receive no 

 telegraphic reports from that direction. We should also like 

 telegraphic reports from a station considerably to the N. of Cape 

 Town, such as Swakopmund in German West Africa, and another in 

 the N of the interior of Cape Colony, such as Prieska. If our 

 friends of the Cape should decide to issue forecasts, they have the 

 means at hand for their Eastern Province, but for the Western 

 Province an ocean station is required ; fortunately one exists in St. 

 Helena, and I have no doubt it could be easily arranged to get a 

 daily weather cablegram from that island. 



Thanks to the co-operation of the other meterological services of 

 South Africa, the numerous voluntary observers in the Transvaal, and 

 the ready co-operation of the Telegraph Authorities, we are now able 

 to make a daily synoptic weather map covering a considerable part 

 of South Africa. I show six of these maps which have been prepared 

 bv Mr H. E. Wood, who has been lately appointed to the Transvaal 

 Meteorological Department, and who has had training in forecasting 

 under Dr. W. N. Shaw, of the Meteorological Office, London. The 

 first map (Thursday, June 21), shows an anticyclone over the O.R.C. 

 with .'ts accompanying light winds. The low barometer and N.W. 

 winds with rain over the Cape Peninsula show the approach of a 

 depression. The next map (Friday, 22 June) shows that the 

 depression has swept along the south coast, bringing considerable 

 rains, but that it had not yet affected the Transvaal, where 

 temperatures were still high and N winds prevailed. The change 

 came on Friday night. The map for Saturday, 23 June, shows the 

 influence of the depression which apparently passed over South Africa 

 in the form of a V. A southerly gale is reported from nearly every 

 station, but it is still calm at Bulawayo. Temperatures are very low, 

 and pressure along the W coast is rising rapidly. The coast rainfall, 

 if any, which would be measured on Sunday morning, is omitted, 

 as we do not receive Sunday wires from the Cape Meteorological 

 Commission, the only coast stations reporting being the Observatories 

 at the Cape and Durban. The Sunday map (24 June) shows a high 

 pressure over the Cape, the influence of the V is now felt at 

 Bulawayo, where a stiff SE gale is blowing. Bitterly cold S winds 

 still prevail over the Transvaal, but the rising barometer indicates 

 a lessening wind and warmer weather. The map for Monday, 25th 

 June, shows that the region of high pressure has moved up to the 

 O.R.C. and Transvaal, whilst over the rest of South Africa pressures 

 are fairlv high and remarkably even. The winds indicate the 

 existence of small local anomalies in the SW, but from lack of data, 

 isobars cannot be drawn. The last map (Tuesday, 26th June) shows 

 that the anticyclone maintains its position over the High Veldt and 

 Natal, whilst a low pressure is passing considerably to the south of the 

 south coast. The indications for a forecast with such a map point 

 to continued fine weather, light winds, sunny days, and cold nights. 



