Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/104

 in the place where they are now found. It may well be, therefore, that these represent the operations of larger furnaces, worked perhaps at a later period, when the art of metallurgy was further advanced than was the case when the thinner and less perfectly melted slags were produced.

At the lower end of the Nash valley there is another slag-heap, of smaller extent, but in other respects similar to that at the springs. A third was found in Wady Gharandel, upon a terrace of Nummulitic or Cretaceous limestone, far away from any place producing copper- ores, but near water, proving that the sites for smelting- works were determined chiefly by the presence of springs, where there is usually some quantity of wood, even at the present time. The charcoal used for smelting appears to have been derived from the Acacia vera, which still flourishes round the springs ; and though of late years the wood has been much cut down, in order to produce charcoal for the supply of Suez and Cairo, many of the trees are of very great antiquity.

I was unable to find any traces of the ruins of large calcining furnaces, and basins that had probably served as stamps and catch-pits, as described by Dr. Figari Bey*. Probably these are only naturally jointed piles of stone, produced by the action of the weather on the sandstone, which breaks up into very regularly shaped masses. It cannot be supposed that the ancient Egyptians were in the habit of subjecting their ores to any complex mechanical treatment, still less to the process of stamping and washing, especially as, according to Haupt, the use of stamps was not introduced in mining until the 16th century.

Nasb Fault (see Pl. I. fig. 5) — Sandstone Outliers. — The fault running through the Nasb valley has a westerly downthrow of about 600 feet. A second fault of the same kind, nearly parallel, and with a downthrow in the same direction, traverses the next higher valley, known as Wady Lechian, where the lower crystalline schists, studded with numerous intrusive dykes, come to the surface and form a very rough ridge about 500 feet in height, above which the red-sandstone series occurs in the usual order, attaining a height of about 1000 feet more in the peak of Om Riglaine, which is really a great outlier of nearly horizontal sandstone upon the plateau of crystalline rocks, the summit being a narrow ridge of about 30 or 40 yards in length and about 3600 feet above the sea-level (3609 feet by barometrical determination). Several other outliers of the same character, but rising to greater heights, are seen from the top of Om Riglaine, the most important being a twin peak close by and two great masses to the eastward, which do not appear to have any special name other than Gharabi, which is applied by the Arabs as a kind of generic term to all mountains that are not endowed with names derived from poetical or legendary sources. In Wady Suoug, or Saaou, to the south-east of Nasb, the crystalline schists are continuously exposed at the bottom of the cliff, the upper sandstone being cut up into a number of tributary valleys. On the northern side, however, the


 * 0p. cit. vol. ii. p. 647.