The _Iron Foundries at Hayle_ are well deserving of notice, and here some of the largest engines used in the mines were cast. The _Water Dam_ which was constructed about 30 years ago, (near the house where the copper was formerly smelted,) for scouring out the sand from the harbour, has been attended with the most beneficial effects. It is now in contemplation to have a causeway built across the Hayle, the estimate for which amounts to about _£_5,000; and which, if accomplished, will be highly beneficial. The singular and desolate appearance of the whole surface of the country in this neighbourhood, which, with few exceptions, extends even as far as Padstow, excites the attention of every stranger. The immense banks of sand which have been thrown up on the coast, have been a great injury; and in some instances, many dwellings have even been buried by the shifting of the sands; here human bones have also been frequently discovered, supposed to have belonged to cemeteries which have been inundated during violent hurricanes. Many of the above particulars were obligingly communicated by Sir Christopher Hawkins, Bart., M.P., and Recorder for St. Ives; and who also has a seat, called Trewinnard, in this part of the county. _Tredea_, which is near to Trewinnard, is the property of Davies Gilbert, Esq., M.P. for Bodmin, and President of the Royal Geological Society at Penzance. With the view to enable mineralogists to prosecute their endeavours, it is necessary on their proceeding into Cornwall, that they should visit the most interesting collections in the county. Of these may be ranked the valuable collection belonging to William Rashleigh, Esq., at Menabilly, near Fowey, which has been noticed in a former part of this work. In this splendid collection are some very magnificent _oxide of tin_, _fluors_, _melachite_, and some very rare varieties of _sulphuret of copper_; wood tin forming a vein in a matrix of quartz, to one side of which adheres a fragment of rock. An account is given in the first volume of the transactions of the Penzance Geological Society. Here are also some fine specimens of _yellow copper ore_, with _opal_; triple _sulphuret of antimony_; _copper and lead_ in various forms; _ruby copper_ in _cubes_; _quartz_ with water in globules; _topazes_ of beautiful lustre; and _green fluor_, in crystals with 24 sides. Many of the specimens above enumerated are of considerable value and scarcity, besides which there are also many others highly interesting. They are contained in a spacious apartment, which has been fitted up in the most elegant manner, with glass cases to prevent them from being injured. Mr. Rashleigh takes great pleasure in allowing strangers to visit his collection, and is entitled to every mark of commendation for his politeness on such occasions.