The Circle of the Sciences; A Series of Treatises on the Principles of Science, with Their Application to Practical Pursuits ...

The Circle of the Sciences; A Series of Treatises on the Principles of Science, with Their Application to Practical Pursuits ...

List price: US$10.70

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks

Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1860 edition. Excerpt: ...In others again (probably a small number), there appears to have been injection of mineral matter in a melted state: while, in all probability, the whole number have undergone great subsequent change, and may have been entirely filled in consequence of a scgcgation of particles from the mass of the containing rocks, and from the contents of the vein, so as to produce these complicated crystallizations and varied mineral and metallic substances often met with. In addition to this, and as further illustrating the subject, it may be added that productive veins are found, in most cases, to contain alarger proportion of metalliferous substances ncar cross courses, close to and at the point where a vein enters a different rock from that which it has hitherto traversed, and near the points where strings and largemcnt of a lode is often a sign of poverty. The divergence of a lode into a number of small ones is also unfavourable; and a great mixture of minerals is not generally likely to lead to an abundant supply of any one. Gossans.-With almost all lodcs in certain districts, and with certain classes of veins generally, there is so large a quantity of iron present that the decomposition of this metal near the surface produces a fcrruginous stain. The tops of many lodes (near the surface) are also not unfrequently open, cavernous, and formed to a considerable extent of iron oxide. Thus in Cornwall, and many parts of Germany and France, in mineral districts, an irony appearance of a vein, where seen at the crop, is regarded as favourable. In Cornwall such an appearance is called a gossan, and a Cornish miner is apt to believe that a good gossan necessarily leads to a good vein in the depth; and, on the other hand, that no large vein is worth...show more

Product details

  • Paperback | 306 pages
  • 189 x 246 x 16mm | 549g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236811003
  • 9781236811004