1811. ASTRONOMICAL OBSERVATIONS. — ASBESTOS. 
333 
grees ; nor can he, at any time, make use of more than the half of 
the number of stars which pass the meridian ; those towards the 
horizon being too low to be observed with convenience, or with 
certainty, on account of an atmospheric refraction influenced by 
variable causes. 
Little notice as the Hottentots, in general, take of mineralogical 
objects, their attention has been attracted by a production of these 
mountains, which, observing to have the singular property of be- 
coming, on being rubbed between the fingers, a soft cotton-like 
substance, resembling that which they made from their old hand- 
kerchiefs for the purpose of tinder, they have named Doeksteen, 
(Handkerchief-stone, or Cloth-stone). They pointed out a particular 
part of the mountains where it might be found ; and I made an 
excursion for the purpose of examining it, and at the same time to 
explore the Kloof-Valley and its productions. 
The Doeksteen is a kind of Asbestos, of a blue color. Havinx? 
found the spot, I made a drawing of the remarkable laminated rocks, 
between the thin horizontal layers of which it is found. * These 
veins of asbestos are of various thickness, from the tenth to half an 
inch, and consequently their fibre, which is always transverse, is very 
short. But, in the mountains, at a place called Eland's Fountain, 
about five and twenty miles north-eastward, some is found, the 
fibres of which are above two inches long. This is, in fact, another 
species, and differs not only in the length, but in the more compact, 
perfectly straight and glossy fibre, and in its deeper color. The 
more remarkable circumstance is, the existence of Asbestos in 
mountains of argillaceous schistus. All the rocks at this place are 
formed of thin plates of this clay-slate, not more than half an inch 
* An engraving of one of the crags of the Asbestos rocks, is given at the end of the 
chapter. This rock is formed of primitive argillaceous schistus, or clay-slate, and in the 
crag here represented, the strata ai'e undulated ; although in other places they are 
generally flat. Between these the Asbestos is found in alternate and parallel strata; the 
fibres of this mineral being perpendicular, or transverse, with respect to the layers. The 
shrub, represented growing upon it, is the Acacia detinens, or Hook-thorn, described at 
pages 309 and 310. 
