formed, that _Zeolite_, its frequent associate, and an equal stranger to Cornwall, might shortly make its appearance. This opinion has been lately verified by the discovery of, at least, two varieties of that mineral, imbedded in the _Prehnite_ vein, viz. _Stilbite_, or _foliated Zeolite_, crystallized in flat four-sided prisms, with quadrangular summits; and the _radiated Mesotype_, which sometimes contains nodules of _Prehnite_. Other specimens have been found in rather an earthy state, and may possibly be the _mealy Zeolite_ of Jameson. In the same slate rocks _Apatite_ occurs of a yellowish-green colour, and crystallized in hexaedral prisms. In the granite rocks on the high hills south-east of Trewellard, _Pinite_ is to be observed. We arrive at the "_Crown Engine_" of Botallack-- "How fearful And dizzy 'tis to cast one's eyes so low, The crows and choughs, that wing the midway air Show scarce so gross as beetles:---- ----I'll look no more, Lest my brain turn, and the deficient sight Topple down headlong." This is undoubtedly one of the most extraordinary and surprising places in the mining districts of Cornwall, whether considered for the rare and rich assemblage of its minerals, or for the wild and stupendous character of its rock scenery. Surely, if ever a spot seemed to bid defiance to the successful efforts of the miner, it was the site of the _Crown Engine_[58] at Botallack, where at the very commencement of his subterranean labours, he was required to lower a steam engine down a precipice of more than two hundred feet, with the view of extending his operations under the bed of the Atlantic ocean!!! There is something in the very idea which alarms the imagination; and the situation and appearance of the gigantic machine, together with the harsh jarring of its bolts, re-echoed from the surrounding rocks, are well calculated to excite our astonishment. But if you are thus struck and surprised at the scene when viewed from the cliff above, how much greater will be your wonder if you descend to the surface of the mine. You will then behold a combination of the powers of art with the wild sublimity of Nature which is quite unparalleled; the effects of the whole being not a little heightened by the hollow roar of the raging billows which are perpetually lashing the cliff beneath. In looking up you will observe troops of mules laden with sacks of coals, for the supply of the engine, with their undaunted riders, fearlessly trotting down the winding path which you trembled at descending even on foot. As you approach the engine, the cliff becomes almost perpendicular, and the ore raised from the mine is therefore drawn up over an inclined plane,[59] by means of a horse engine placed on the extreme verge of the overhanging rocks above, and which seems to the spectator below as if suspended in "_mid air_."