every
valley is dotted with the homes of those who follow this business.
Agate polishing has also been carried on of late years at Waldkirch in
Baden.
In
1770 there were only 26 cutting and polishing mills in Birkenfield,
whereas in 1870 there were 180. In each mill there are four or five
grindstones. These are of red sandstone, obtained from Zweibrücken ;
and two men ordinarily work together at the same stone. The Agate is
usually cleaved to the requisite form by means of the hammer, a work
which exacts much skill from the artisan : for he must be well
acquainted with, the natural grain of
the Agate, since there is no true cleavage to guide him. One of the most interesting branches of the Agate
industry is that of colouring the stones by artificial means.
This subject has already been dealt with on pp. 48—51. In the amygdaloidal rocks of Perthshire, Forfarshire,
and other parts of Scotland, Agates of very pleasing
patterns are found. These are cut and polished under the
name of "Scotch Pebbles," and are employed as ornamental
stones in common jewellery.
AGATE.
