Ill—REPORT ON METEOROLOGICAL AND 
ALTIMETRIC OBSERVATIONS MADE BY 
H.1I.H. THE DUKE OF THE ABIiUZZI’S 
EXPEDITION TO RUWENZORI 
By Prof. DOMENICO OSIODEI. 
The meteorological observations were made during the whole journey, 
from 16th May to 12th August, for the twofold purpose of first giving an idea 
of the climate of these regions, at least for the short time of stay, and then of 
determining, at least approximately, the altitudes of the various places, and 
especially of the more important points of the Ruwenzori Range, which was the 
chief objective of the expedition. 
The instruments used in the observations consisted of three mercurial 
barometers* of the Fortin type, one registering barometer, three aneroids, two 
hypsometric thermometers, three thermometers and one psychrometer. 
Before starting, these instruments were carefully compared with the 
normal instruments, and to all the data, which are recorded farther on, were 
applied the terms of correction thus established. 
During the first part of the journey from Entebbe t to Fort Portal, from 
16th to 28th May, the observations for pressure, temperature and humidity, 
as well as those relating to the state of the weather, were taken every day at 
noon, while other less complete observations were made at 15 and 21 o’clock. 
The summary of the observations is contained in the accompanying Table I. 
The maximum and minimum temperatures have reference to the whole period 
of the stay of the expedition in a given station, that is, generally from about 
10 or 11 in the morning till the first antemeridian hours of the next day. 
* Two graduated from 720 to 240 mm., and one from 480 to 290 mm. for the uplands, 
t Here there is an observatory, the altitude of which is known, hence it was taken as 
the basal station for the determination of the altitudes of places between Entebbe and Fort 
Portal. 
361 
