[112] This is the deepest _Adit_ in the country; its mouth or extremity being nearly on a level with the water in one of the creeks of Falmouth Harbour, into which it empties itself. Taking into calculation its various windings, through the numerous mines which it relieves of water, it may be said to be not less than twenty-four miles in length. [113] Menabilly is situated about four miles west of Fowey, on an eminence at a short distance from the sea. [114] We have been told that this has been arranged by Mr. Aikin, according to the different modifications of its crystalline form, as they are described by Mr. William Phillips in his elaborate paper published in the 2nd Vol. of the Transactions of the London Geological Society. [115] See an interesting account of this mineral in a notice entitled "Contributions towards a knowledge of the Geological History of Wood-Tin, by A. Majendie, Esq." in the first volume of the Transactions of the Royal Geological Society of Cornwall. [116] Since the first edition of this work was printed, the mineral has been found at _Saint Michael's Mount_, and, by Dr. Boase, amongst a pile of ore which was supposed to come from _Botallack_. [117] In one of which is to be seen the _Muriate of Tin_, as first noticed by the late Reverend William Gregor. [118] The following are the names of the respectable dealers to whom we recommend the mineralogist to apply,--At _Truro_, Tregoning, Mudge, and Heard;--at _Redruth_, Bennett; at _Gwenap_, Michell;--at _Saint Agnes_, Argall;--at _Falmouth_, Trathan;--and at _Penzance_, Jacobs, the latter of whom has generally a great variety of Saint Just minerals on sale. [119] OPIE was a parish apprentice to a person of the name of Wheeler, a house carpenter, in the village of Saint Agnes; Dr. Walcott, better known by his poetical appellation of _Peter Pindar_, having been struck, during his occasional visits to the village, by some rude sketches in chalk which were shewn him as the productions of this poor lad, invited him to his house at _Truro_, supplied him with the necessary materials, and enabled him to set up as an itinerant portrait painter, from which station he rose to be Professor of Painting to the Royal Academy. [120] A highly interesting paper "On the decomposition of the Granite Tors of Cornwall," by this geologist, is published in the second volume of the Transactions of the Geological Society of London. [121] This may be distinctly seen in the granitic rocks in the islands of Scilly; and in the _Gritstone_ in the park of the late Sir Joseph Banks, in the parish of Ashover in Derbyshire.