The Engineer's and Mechanics Encyclopædia: Ochre.

The Engineer's and Mechanics Encyclopædia,
comprehending practical illustrations of the machinery and processes employed in every description of manufacture of the British Empire.
With nearly Two Thousand Engravings.
By Luke Hebert, civil engineer, edifor of the History and Progress of the Steam Engines, Register of Arts and Journal of Patent Inventions, etc.
In two volumes.
VOL. II.
London: Thomas Kelly, 17, Paternoster Row.
MDCCCXXXVI (1836).
Ochre, (red,) is an iron ore of blood-red colour, which is sometimes found in powder, and occasionally in a hardened state. It has an earthy texture, and sometimes stains the fingers when handled. The principal use of red chalk is for drawing. For the latter purpose, it should be free from grit, and not too hard. In order to free it from grit, and render it better for use, it is sometimes pounded, washed, mixed with gum, and cast into moulds of convenient shape and size. Under the name of reddle, this substance is much used for the marking of sheep, and when mixed with oil, for the painting of pales, gates, and the wood-work of out-buildings.