Before concluding this brief sketch, a few words must be said on the beds of clay, sand, and gravel which cover the low grounds, both on the granite and on the slate. These may be resolved into two kinds: 1st. those resulting from the decomposition of the rocks, and which are in their original position; and 2d. those which are not _in situ_, affording by their appearance, composition, and position, evidence of their having been transported. These deposits belong to three distinct periods, and alternate with terrestrial and marine remains, according to their situation in respect to the sea-level at their respective epochs. Each of these transports was accompanied, or followed by, a change in the sea-level: the last corresponds with that now existing; the previous one, by the elevated ancient beaches, indicates that the sea was about fifty feet above its present level; and the earliest transport, being covered with sub-marine forests, shows that the sea was at that epoch at least fifty feet lower than it now is. (See 4th vol. Geol. Trans. of Cornwall, p. 466, et seq.) In the lowest or oldest deposit the tin-ore (_stream-tin_) is found in the form of sand and gravel mixed with earthy substances: it affords the purest kind of tin, known in the market by the name of _grain-tin_; and appears to be the source from which the ancients derived all their tin. The notices under each parish will furnish more particulars concerning these interesting deposits. ERRATA. VOLUME I. P. 16, note, _for_ Glaveney, _read_ Glaseney. P. 29, line 22, _for_ points, _read_ parishes. P. 45, lines 9 and 12, _for_ Perr, _read_ Parr. P. 47, lines 7 and 8, _for_ Pentwan, _read_ Pentewan. P. 48, line 15, _for_ Puntner, _read_ Pentewan. P. 52, line 4, _for_ Parc, _read_ Parr. P. 76, line 20, _for_ Beni, _read_ Berri. P. 87, line 18, _for_ Kint, _read_ Kent; line 31, _for_ has, _read_ had. P. 113, line 2, _for_ 1623, _read_ 1643. P. 141, line 5 of note, _for_ Penrith, _read_ Penwith. P. 151, In Callington, line 8, _for_ Mellior, _read_ Mellion. P. 153, line 27, _for_ sine, _read_ sive. P. 158, line 15, _for_ Bodrigar, _read_ Bodrigan. P. 210, line 18, _for_ Ludgnan, _read_ Ludgvan. P. 222, line 7 from foot, _for_ Solverne, _read_ Talverne. P. 226, _for_ Mane Mine, _read_ Manor Mine. P. 244, line 3 from foot, _read_ Glanville, of Catchfrench. P. 260, line 15, _for_ Disporth, _read_ Duporth. P. 298, line 11 from foot, _for_ Carreth, _read_ Carveth. P. 328, line 12 from foot, _for_ St. Veye or St. Vewe, _read_ St. Udey or St. Kewe. P. 342, line 14, _for_ Donechenir, _read_ Donechenin. P. 360, line 20, _read_ a small neat house. P. 397, line 19, _for_ Seawen, _read_ Scawen; line 25, _for_ Treladra, _read_ Treludra. VOLUME II.