Philadelphia Paper - Ore Dressing and Smelting at Pribram, Bohemia

The mining town of Pribram is situated in Central Bohemia, on the western slope of the Heiliger Berg. 30 miles southwest from Prague. Birkenberg, the village ill which most of the shafts and ore-dressing establishments are situated, is built on a mountain of the same name. It is about a mile from Pribram, is 1700 feet above the sea, and is surrounded by graywacke rocks of Silurian origin, which arc intersectd by greenstone dikes, and in the southerly, southeasterly, arid southwesterly direction are bounded by granite. The graywacke formations consist on one side of graywacke sandstone and quartzite, and on the other of graywacke slate. These last are separated from the first in the immediate vicinity of the mines by a graywacke seam converted into clay. For many years this so-called clay seam (lettenkluft) was considered as a boundary of the ore deposits in both zones of graywacke. The graywacke formation L divided according to its harduess, structure, texture, and color, into fine, coarse, compact, slaty, whitish-gray, reddish-gray, and black graywacke. The miner divides the formation into four divisions. The first or lowest division, which is in contact with the granite, consists of a fine-grained dirty gray slate; the -second is a very fine to a very coarse schist, white to reddish-gray in color, and rich in quartz, but containing little mica; the third consists of a slate with a confused cleavage, which has a dirty gray, dark gray, and very often black color and is often graphitic in its composition; the fourth consists of a fine to coarse-grained graywacke schist, of a grayish-white or reddish-gray color, and rich in quartz. The cleavage in all four divisions strikes from northeast to southwest, and the dip is sometimes northwesterly, sometimes southerly, and often vertical. All four zones are cut through by a great number of diorite arid greenstone dikes and chimneys. The thickness of these dikes, which are of