Appendix B. 
At the Entebbe Observatory the meteorological observations were regularly 
carried out three times in the day, at 7, 14 and 21 of mean local time, which 
differs 2 hours, 8 minutes and 45 seconds from mean Greenwich time, whereas 
those of barometric pressure during the journey could be made only at noon 
of local time. 
Hence in the absence of synchronous corresponding data of Entebbe, for 
the pressure the mean of the hours 7, 14 and 21 has been assumed, and from 
this mean the pressure at noon may, generally speaking, be taken to differ but 
slightly. For the temperature and the tension of aqueous vapour that of 
the nearest hour, that is 14, has been assumed. In Table II have been brought 
together the data of the observations made at Entebbe* between 16th and 
28th May. From the data supplied by the two Tables I and II were calculated 
the altitudes of the various stations relatively to Entebbe by means of the 
formula : t 
/ 1 
Z = 18400 (1,00157 + 0,00367 6) — 
1 - 0,378 - 
\ V 
(1 +0,00259 cos 2 X) (l+|^)log| 
where Z expresses the difference of level between the two stations. 
H 0 the pressure reduced to 0° in the lower station. 
H the pressure reduced to 0° in the upper station. 
6 = 
/„ + t, 
the mean between the temperature t 0 of the air in the lower 
station and that of t in the upper station. 
0 
— ~ the mean between the vapour tension /„ in the lower station 
and / that of the upper station. 
IB + H 
A the latitude, 
z the latitude of the lower station above sea-level. 
The headings H 0 , t 0 , /„, H, t, f, which figure above the columns in the 
following tables, refer to the use of the formula for the calculation of which use 
has been made of the “ Tables Meteorologiques internationales ” (Paris, 1890). 
* According to the certificate of the “ National Physical Laboratory,” the barometer of 
the Entebbe Observatory has a correction of — O'OOl inch. 
f This formula of Kuhlmann has been adopted without more ado as the most general and 
complete, since a discussion on the choice of altimetric formulas, which should take account 
of the recent results on the law of variation of the meteorological elements in the open air 
and on the slopes of the mountains, would not be in accord with the few available data, data 
which, moreover, cannot always be obtained under the best conditions. 
362 
