This section is from the book "Tree Planting For Timber And Fuel", by C. B. Mcnaughton.
Rust-en-Vrede is situated to the N.E. of Oudtshoorn and about 21 miles distant from it. It is connected with the town by a fairly good road for the most part—as far as the junction at Schoeman's Hoek—and by a road which a comparatively small outlay would ronder quite practicable for timber transport for the remainder. It is possible that it may be served to an extent by rail communication should a light line be constructed to the Cango Valley from Oudtshoorn. At the base of the Zwartberg Mountains and at an elevation of 2200-2800 feet above sea level its position is approximately 33° 28' S. Lat. and 22° 30' E. Long.
The principal soil forming rocks appear to be sandstones, clay slates and here and there a dark blue schistose rock. To the south of the homestead and quite close to it a dark blue crystalline limestone is to be found interbedded apparently with clay slates. The soil appears to vary somewhat both in character and depth—sandy and stiff clays predominating—varying probably with the percentage of contained lime etc. The whole appears to be very suitable for tree planting.
With regard to climatic conditions it is somewhat difficult to obtain any fairly accurate estimate, as no sufficient meteorological records exist nor are any apparently available for the district, for not even a second order meteorological station has been established, within its boundaries, as far as I am aware, but I write under correction. Fortunately at Rust-en-Vrede two rain gauges were put up, in connection with the surveys etc. for the town water-works, and while the rainfall measurements taken with them appear to have been somewhat interrupted during the recent invasion of the Colony, some information is available.
From what is possible I have drawn an average monthly chart, which I attach, and compared it with that obtained from a good many years' observations in the town of Oudtshoorn situated some 1400 feet lower. The rainfall appears to average about 24 inches per annum as against 9.34 for Oudtshoorn with a summer (October— March) percentage of about 50 degrees. The principal rains appear to fall about late autumn or early spring, the heaviest probably in the latter season.
With regard to the other climatic conditions only a rough guess can be made, based on a comparison with records in other parts of the country and applying a correction of a decrease of 1.5° Fahr: for an increase of 1° of Latitude and a decrease of 3° for every 1000 feet of elevation above sea level. This correction agrees generally with observations made in this country though it is claimed that in the main plateaux of South Africa a difference of only 1° for every 440 feet of elevation is more consistent with fact. For present purposes therefore the following figures may be taken as a guide to the mean monthly temperature :-
The mean temperature for the summer months may be taken as 75°; the maximum temperature likely to be experienced as about 98°, and the minimum at about 27° or 5 degrees of frost. It must be remembered that ground temperatures will prove somewhat lower than this and some ground frost may be expected as late as October. It would be advisable to establish a set of instruments consisting of two sets of thermometers, maximum and minimum, for observations at the usual height in a Stevenson's screen and at ground level and the ordinary wet and and dry bulb thermometers and barometer. Very possibly the Meteorological Commission would supply what is necessary as the station cannot fail to prove of interest. Of course this can only be done when the instruments can be placed in the charge of a competent person.
While I could gather little or no information as to actual observation it seems probable that heavy winds from the northwest or northerly direction are experienced and that especially in the upper portions of the farm there is some danger from mountain fires, as the veld here has the appearance of having been burnt on several occasions.
Having roughly assessed the conditions the following recommendations appear called for:—