For the information of the Geologist who may visit this spot, we shall state, that in a porphyritic granite on the summit, Mr. W. Phillips has lately discovered that some of the crystals formerly considered as _Felspar_, were _Cleavelandite_;[122] and we have little doubt that this curious discovery might be extended to many of the granitic masses in Western Cornwall. At the eastern end of the hill is _Carn-breh Castle_; the rocks upon which this building stands, not being contiguous, are connected by arches turned over the cavities; one part of the fortress pierced with loopholes is evidently very ancient, and is supposed to have been of British work; the other is of modern construction, and was probably erected as an ornamental object from the grounds of Tehidy. There were formerly some outworks to the north-west; and, near the summit of the hill is a circular fortification called the _Old Castle_, which appears to have been included within a strong wall. The hill itself, on which the spectator stands, is quite in unison with the scene around him; its silence and desolation,--the awful vestiges of its convulsion,--and the immense rocky fragments which lie scattered on its brow, are well calculated to harmonize with an extended and barren tract of country, every where broken up by mining operations, and whose horizon is bounded by the ocean. FOOTNOTES: [84] The Phoenicians traded upon the western coasts of Cornwall, for at least six hundred years before the birth of our Saviour, and that for the sake of Tin;--so that the antiquity of our tin trade has been established upon mercantile principles for not less than twenty-four centuries. But in the earlier ages this metal was all procured from _Stream Works_, the method of working mines not having been known and practised for more than seven hundred years. [85] In the year 1822, the produce of the Copper mines in Cornwall amounted to 106,723 tons of ore, which produced 9,331 tons in Copper, and £676,285 in money. Whereas the quantity of Tin Ore raised did not exceed 20,000 tons. [86] The Saxon Miners formerly regarded _Cobalt_ in the same way. They considered it so troublesome when they found it among other ores, that a prayer was used in the German Church, _that God would preserve Miners from Cobalt, and from Spirits_. [87] _Lead_ is principally found in cross courses, or north and south veins. _Pentire Glaze_, near Padstow, which has lately produced the finest cabinet specimens of _Carbonate of Lead_, ever found in this country; and _Huel Golding_ in Perranzabuloe, are the principal mines in which the Lead occurs in cross courses. Lately, however, East and West Lodes of Lead have been discovered in the Parish of Newlyn, by Sir C. Hawkins, in draining a marsh. They are about two feet wide. Besides the Lead and a little quartz, they consist entirely of Clay; neither Copper nor Tin have been seen in them. The Lead yields about Sixty Ounces of Silver per Ton.