92 Transactions of the South African Philosophical Society. 
opposite.“ Both have. a tendency to shift against the sun before 
noon: and with the sun afterwards. It is curious that there is a 
wider range in the amount of moisture carried by the winds at night 
than there is by day. The reverse holds with the temperatures, in 
which the greatest ranges are by day, followmg in this respect the 
same law as the pressures. : 
If a line be drawn N.N.E.-S.S.W., all winds from the east side 
come with an average pressure above the mean, and all from the 
west with an average pressure below. This has a further bearing on 
the facts revealed in Fig. 7. The mean temperature line is nearly 
E.—W., and the line of mean dew-points E.S:E.-W.N.W. 
4, Choup.—Only the cloudiness of the sky with reference to 
particular winds is. here considered, no account being taken of the 
sort of cloud. Table 19 gives the average amount of cloud accom- 
panying each wind at 8 a.m., 2 p.m., and 8 p.m., together with the 
mean of the three hours; also smoothed values of each with their 
smoothed mean, which last, plotted to scale, might be called the 
normal curve. The last three lines give the departures from the 
normal. Northerly winds are accompanied by the most cloud, and 
southerly winds by the least. This feature is contributed to in two 
ways: firstly, because in the diurnal range the cloudiness is greater 
at 2 p.m. (when northerly winds are prevalent) than at 8 a.m. or 
8 p.m.; and secondly, because the ruling directions of cloud motion 
have a very large northerly component. The set-in south-easterly 
winds, when they occur, moreover, are in the main anticyclonic, 
with clear skies. But over and above this we have the most signifi- 
cant result that, relatively to the normal curve, the cloudiness of the 
‘sky increases with the deviation of the vane from its normal position. 
In conelusion, it should be said that the whole of the: material of 
this paper has been worked up in spare time, and chiefly by: lamp- 
light ; so that, while every effort has been made to ensure accuracy, 
if a few numerical errors have crept in, ib 1s no more perhaps than 
might be expected. Some eminent professional meteorologist in the 
future will, I trust, be able to make a fuller discussion of the winds 
of Kimberley, and with a lighter handicap, ‘The wind-roses alone 
will repay the most elaborate treatment, and particularly, I believe, 
* The behaviour of the dew-point at 6 p.m. is very anomalous. The prevailing 
winds at this time are south-westerly, which, for the hours included in Table 18, 
are shown to be the driest. But the dew-point curve attains its second maximum 
about 6 p.m.! It would seem, then, that the law of Table 18 does not apply to 
the sunset hours, Certainly the circumstance calls aloud for investigation. I 
hope to discuss this, together with some other points of interest not included 
here, later on. It is somewhat of a mystery where the increase of moisture at 
sunset comes from. } 7 | 
