250 Transactions of the South African Philosophical Society. 
we get Bessel’s formula— 
Qar 
a=ptu,sin(V, oy) + u, sin ( V, + — 
+ u, sin (V; + 5") + ly 
which is sometimes thought to be more advantageous than the 
formula of Lambert.* For the different elements it becomes :— 
1. For the monthly maximum temperature at Durban— 
a = 80°°6 + 5-056 sin (77° 12:8" + 2) 
+ 0:4916 sin (48° 14:3’ + 2?) 
— 0°3934 sin (36° 22°6’ + 3t) 
+ 0°1833 sin (270° + 47) +... 
2. For the monthly mean temperature at Durban— 
a = 71°-2 + 6:144 sin (80° 50-2’ + 2) 
+ 0°769 sin (2° 29’ + 2¢) 
— 0°267 sin (860° + 32) 
+ 0-087 sin (360° + 4t) +... 
3. For the monthly minimum temperature at Durban— 
a = 61°8 + 6964 sin (84° 4°6° + 7¢) 
+ 1:289 sin (324° 51:5 + 2¢) 
— 0°240 sin (33° 41’ + 32) 
+ 0-242 sin (838° 25’ + 47) +... 
4, For the monthly mean pressure at Durban— 
a@ = 30°105 inches + 0°1174 sin (273° 7:7 + 7) 
+ 0:0097 sin (62° 27°7' + 2t) 
+ 0:0065 sin (309° 48’ + 37) 
— 0:0107 sin (815° 34’ + 4%) +... 
5. For the monthly maximum temperature at Kimberley— 
a = 79°3 — 14-775 sin (290° 12 + 2) 
+ 1-604 sin (319° 6-4’ + 2¢) 
— 0-232 sin (21° 1:6 + 32) 
— 0-259 sin (26° 48:7 + 44) +... 
* Kaemtz, ‘“‘On the deduction of mean results from meteorological observa- 
tions” (Quarterly Journal of the R. Met. Soc., vol. iii. p. 120; also EK. H. Schmid, 
Lehrbuch der Met., p. 8). 
