Pressure and Temperature Results for the Great Plateau. 255 
Col. 1 gives the hours ; 
Col. 2 the corresponding values of Z, the sun’s zenith distance, 
obtained from the spherical equation— 
cosc = cosacosb + sinasin bcos C; 
Col. 3 the values of y for the respective winter and summer values 
of the coefficients for daily range of temperature ; 
Col, 4 the values of y when A and B have their annual values ; 
Col. 5 the temperatures hour by hour from the Kenilworth 
(Kimberley) records. These, it must be remembered, are not 
for the same years as the Kimberley temperature numbers used 
generally throughout this paper; nor if the years were the same 
would they be quite the same as the Kimberley hourly tempera- 
tures. They must serve, nevertheless, because no hourly 
temperatures had ever been taken in Kimberley. 
According to this Table the hourly differences between the observed 
and calculated temperatures are appreciably the same at the same 
hours in both summer and winter. In other words, the average 
hourly increase of temperature to noon in summer is to that in 
winter in the approximate ratio of 314 to 455. This greater winter 
rate of increase, together with the previous results elicited, may 
prove that the power of the sun to warm the air is limited, and that 
if it were to stand in the midst of heaven for any length of time the 
temperature over the table-land would not necessarily reach any very 
high degree. We see, for example, that when its zenith distance 
decreases from 66° 37’ to 53° 44’ (arc) it can raise the temperature 
from 67°°7 by 4°°6; but when its zenith distance decreases from 
67° 31’ to 53° 45’ it can raise the temperature from 49°:4 by 9°°5. 
Also at the equinoxes a decrease of zenith distance from 64° 0° to 
51° 32’ will accompany a rise in the temperature of 5°°2 from 62°°2. 
Otherwise by taking averages we have a mean rise of temperature 
per 12 degrees decrease of zenith distance as follows :— 
SUMMA a elec ee Aor3 trom Oo. 
ARDEP O est ales arse eosin Oo On en One 
WAMU Te ec ee she 82:0F ra, 40 oe 
By measuring initial temperatures horizontally to the right, and 
average increase per 12 degrees of zenith distance vertically upwards 
(v.e., using rectangular axes) we get three points on some plane curve. 
Also the three equations— 
4:3 (67-7 —x) =Q 
5:0 (62:2 —-x7) = Q 
8:0 (49-4 -27) =Q 
ING 
