Scientific Results of an Excursion to the Hex River Mountains 87 
feet, 1.¢., 560 feet higher than the Winterhoek. This result was so 
surprising that I did not consider it to be very probable. 
It was during the preparations for the excursion of the Mountain 
Club that Mr. Meiring went to Triangle Station, and meeting Mr. 
Greef, a surveyor from Worcester, there, asked him to take the angle 
of elevation of the Hex River pile from the platform of the station. 
Four observations gave the angle as 4°29’; 4°23’; 4°27’; 4°23’; the 
second and fourth figure being obtained after reversing the theodolite. 
The mean angle consequently is 4°25’ 30”. As the altitude of 
Triangle Station is known exactly by railway levelling, it was only 
necessary to find the horizontal distance of the station from the Hex 
River pile. 
This could not be computed from the map in the Surveyor-General’s 
office, for Triangle Station had not been included in the official survey 
of the country, as I learnt from Mr. J. Bosman, one of the surveyors 
who carried out this part of the work on account of the Government 
about twelve years ago. Mr. Bosman kindly promised to look through 
his journal, and fortunately found the entry of two horizontal angles, 
just enough to enable him to fix Triangle Station on the map. 
From the co-ordinates of his observations he computes the total 
horizontal distance as 53,920 English feet ; hence the height of the pile 
above the level of Triangle Station is 
53,920 x tang. 4° 25’ 30”, or 4,172 feet. 
The correction for refraction and curvature of the surface of the earth 
amounts to 60 feet, and the altitude of Triangle Station, as ascertained 
by railway levelling, is 3,193 feet; hence the total height of Matroos- 
berg is 7,425 feet. 
Although it was almost certain that this result must be very near 
the truth, | wished to verify it on my ascent of the mountain. For 
this purpose I took with me a pocket aneroid and a hypsometer with a 
Centigrade thermometer, which would have enabled me to read off 3 of 
a degree, corresponding to a difference in altitude of 60 feet. 
I had made arrangements that there should be simultaneous readings 
of the barometers and thermometers of the meteorological stations at 
Worcester, Ceres, and Matjesfontein, and I had also left a barometer, 
kindly lent by the Meteorological Commission, at Hex River East 
station. During the day previous to the ascent I compared the aneroid 
with the mercurial barometer, and read all the instruments again on 
the morning of the excursion, while a friend of mine kindly undertook 
to read the instruments at the station during theday. WhenI reached 
the summit of the mountain it was nearly one o’clock, and the party 
waiting there was anxious to descend as soon as possible. 
7 
