SOUTHERN AFRICA. 33 
ches radius, by Ramfden ; an artificial horizon ; a good pocket 
chronometer j a pocket compafs ; and a meafuring chain. Hav- 
ing been able, in the courfe of a few days, to afcertain pretty 
nearly the ufucd rate of travelling with waggons drawn by oxen, 
I carefully noted down the time employed from one halting 
place to another, with the diredion of the road, as pointed out 
by the compafs. 
The uniform pace of the oxen, the level furface of the great 
Karroo or defert, and the (Iraightnefs of the road, were data 
that might alone have fupplied a fketch of tolerable exadnefs \ 
but, in order to afcertain any little deviation that might have 
been made, either to the northward or the fouthward, a meri- 
dional altitude of the Sun was regularly taken every day, the 
conftant clearnefs of the weather being favourable for fuch ob- 
fervations. A feries of latitudes thus obtained, at intervals of 
about twenty miles of diftance, fupplied a corredion by which 
the route might be reduced to a great degree of certainty. 
The ftations or refting-places of each day being verified by 
thefe means, I then took the bearings, and made interfedions, 
of any remarkable point in the diftant mountains, as long as it 
could be feen, for the purpofe of determining its pofition upon 
the chart. The uninterrupted lines, in which the chains of 
mountains generally run on the fouth part of the continent of 
Africa, are particularly favourable for laying down a fketch 
of the country, without going through the detail of a regular 
furvey. 
Having 
