Pressure and Tenperature Results for the Great Plateau. 257 
the smallest value of the equation being 44°°136 C., and the greatest 
44°-174C., as compared with an extreme error of 0° 1 F. at Kimberley. 
The only other hourly temperatures that have been tested in this 
way are for three (all that are available) incomplete years from Hong 
Kong in N. Lat. 22° 16". They surrender to the same treatment the 
equation, in Fahrenheit degrees, 
t(T — 34-1) = 36:3, 
but the errors amount to fully three-quarters of a degree—which 
might be accounted large for a place with such a small daily range of 
temperature, did the available observations cover a longer period. 
At the least, whether the changes of temperature be exactly or 
only approximately asymptotic, we conclude that the air of the table- 
land responds to the solar energy the more vigorously the more it 
happens at any time to be found below its theoretical temperature for 
that concomitant altitude of the sun; and that the time it requires to 
attain to its highest temperature is a question rather of hours than of 
days. The great lagging at Durban of more than a month must be 
regarded as pre-eminently due to the adjacent ocean per se. As to 
the atmospheric moisture rising from the water, its effect is probably 
infinitesimal by comparison, whether it be condensed into clouds or 
not. Nor does the ocean domain, meteorologically speaking, end 
with the shore, as is attested by Tables 33 and 34, in which the 
monthly means of maximum and minimum air-temperature, extracted 
from the annual reports of the Cape Meteorological Commission, are 
given not in districts but in sets according to distance from the sea ; 
and by Tables 35 and 36 giving the monthly means of temperature, 
and of range of temperature, deduced from 33 and 34. The periods 
of observation vary from ten to seventeen years. The respective 
latitudes, altitudes, and distances from the sea are given more or less 
accurately below :— 
1. Coast Stations :— 
Distance 
S. Latitude. Altitude. from sea. 
Dur bameceen.ce- a 29° 51’ 260 feet 24 miles 
East London...... ja 2 BIOs. yp OMe. 
Port Elizabeth... 33 58 Sites ve Onna. 
Mossel Bay ...... jaan leh NOS) 255 Om Ee 
Cape L’Agulhas 34 50 OB 5, Oui. 
Simonstown ...... 34 12 De 0 
Average ...... 34° 2’ 64 feet 
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