^44 A. G. Howard.-— The [May 4, 



C to A, and as the pressure at N is greater than at D, the barometer 

 will increase from A to N. 



Hence whichever way the system is travelling, the barometer will 

 fall till A has passed, but there will be a great difference in the 

 manner of the changes, for while the gradient from C to A is gradual, 

 that from N to A is very abrupt. 



So that if with a north-east or north wind, the barometer falls very 

 suddenly, we may almost be certain of rain falling when the barometer 

 begins to rise, especially if heavy cumulus or cumulo-stratus clouds 

 are seen to the south-west, from which direction the following winds 

 will blow. 



When a depression is advancing on us from the north-west, the 

 first indication of its approach is a sudden rise of the barometer, and 

 the appearance of long horizontal strips of cirro-stratus to the north- 

 west. These strips follovr one another and rise higher and higher. 

 Cirro-filum are often seen before this, in long parallel threads from 

 north to south. When the cirro-stratus has reached the zenith, banks 

 of other and lower cirri come up from the north-west, and the baro- 

 meter begins to fall, the wind then blowing from the east or south- 

 east. As the depression advances, heavier and lower banks of clouds 

 come up till the whole sky is overcast and rain begins to fall. As 

 soon as the barometer begins to rise, which it does suddenly, rain 

 falls in heavy squalls, and the wind blows strong from the 

 north-west. The storm has passed and fine weather follows. 



At Cape Town we very seldom have the centre of such a depression 

 pass over us, but when it does, a black south-easter is followed by 

 showers from the north-west. 



In summer time the centre generally passes to the north-east of 

 us, so that the winds^are easterly as the centre approaches, south as 

 it passes, and west after it has passed. Rain very seldom falls here, 

 but they are the great rain bringers of the East and Natal. 



In winter the centre generally passes to the south-west of us, 

 the wind being then from the north-east as the centre approaches, 

 then north and north-west, and finally west, with rain squalls 

 -ending in fine weather. 



Some of our seveiest winter storms are of this type. In these the 

 greatest amount of rain falls before the barometer rises. 



The great majority of our winter storms are of a different type. In 

 .ijiese the polar current is displacing the equatorial one, hence the 

 sudden manner in which they come upon us. The advance wind of a 



