[123] Before his departure upon this excursion, we recommend him to examine the very instructive suite of specimens which were collected, and deposited in the Cabinet at Penzance by _Mr. Ashhurst Majendie_, a gentleman whose geological labours in this country are well known, and whose zeal and ability so greatly promoted the early advancement of our Geological Society. This valuable series has been greatly augmented by a Collection since presented to the Society by _The Reverend John Rogers_. The Geological tourist ought at the same time to make himself acquainted with the observations of _Mr. Majendie_ "_On the Lizard District_," in the first volume of the Transactions of the Royal Geological Society of Cornwall; and those of _Mr. Professor Sedgwick_, on the same subject, in the Transactions of the Cambridge Philosophical Society. [124] In the _Greeb-rock_, an insulated mass of greenstone in the sea beneath, there is a vein of _Asbestus-Actynolite_, mixed with _Axinite_, from four to twelve inches wide. This is a curious spot, well worthy the attention of the geologist. [125] As will appear on the perusal of the first edition of this little work. [126] A violin is in some parts of Cornwall called a _Crowd_, whence doubtless the name of _Crowdero_, the fiddler in Hudibras. [127] The ancient name of Helston. The modern apellation is derived from a huge block of Granite which may be seen in the yard of the Angel Inn--_Hellas-stone_, or _Helston_. [128] On the physical structure of the Lizard district, by the Rev. A. Sedgwick. [129] The same relative position of these rocks may also be observed at _Cadgwith_, an interesting part of the coast north-east of the Lizard Point, and which we shall have occasion to notice hereafter. [130] Sir H. Davy, in a paper on the Geology of Cornwall, published in the first volume of our Transactions, observes that "the nature and origin of the veins of _Steatite_ in Serpentine are curious subjects of inquiry. Were they originally crystallized, and the result of chemical deposition? Or have they been, as for the most part they are now found, mere mechanical deposites, I am inclined to the last opinion. The _Felspar_ in Serpentine is very liable to decompose, probably from the action of Carbonic acid and water on its Alkaline, Calcareous, and Magnesian elements; and its parts washed down by water, and deposited in the chasms of the rocks, would necessarily gain that kind of loose aggregation belonging to Steatite." [131] It might on this account be worth while for the Glass-maker to try the effects of a small mixture of _Steatite_ with the materials of which he makes his large crucibles, in order to prevent that great degree of shrinking to which they are now so liable.