Mr Harvey received him cordially. "I am about to ask you, Mr Gilbart, to accompany my son Frank on a tour of considerable extent, to visit some of the more important mines in Europe, and, if there is time, in other parts of the world, and he is anxious to have a practical man who will enable him to comprehend the different matters connected with them more clearly than he would be able to do by himself. I need not say that I am fully aware of the value of your time, and I therefore offer you such compensation as I hope you will consider sufficient." Mark gladly agreed to the proposal. Such a tour was above all things such as he desired, and which, indeed, he had himself contemplated taking at his own cost. Frank Harvey was an active, intelligent, young man, exactly the sort of companion Mark would have chosen. Having concluded all their arrangements, they lost no time in setting out. Having visited the English, Scotch, and Welsh coal districts, numbering in all about fifteen, they bent their steps--after seeing the iron and lead mines in the south of Scotland, and the north and centre of England--towards Cornwall, to explore its tin and copper mines; after which they intended to cross the Channel to visit the more remarkable ones of Europe. Their first halting-place was at Redruth, near which is the lofty hill called Cairn Brea, whence they obtained a view over an extensive mining district. The country around, covered in many places with enormous blocks of granite, looked barren and uninviting in the extreme, and no one would have supposed that any portion of the soil in sight was the richest in the whole of our island. Within a few miles of the spot where they stood were, however, numerous copper and tin mines, many of which had yielded a large profit to their owners. Among them was Dolcoath, one of the oldest copper mines in Cornwall, 300 fathoms in depth. Another, Eastpool, a tin and copper mine, from which ores to the amount of 130,000 pounds have been won, after an original outlay of only 640 pounds. From the former mine native silver, cobalt, and bismuth have also been obtained. The mineral deposits of Cornwall, it should be known, are found in granite and grey slate. Those of Derbyshire and the north of England--lead and iron--in the carboniferous system. The travellers visited these and several other mines, among them the Consolidated Copper Mines, situated in the parish of Gwennap, about three miles from Redruth. They extend along the brow of a range of steep hills, into which numerous shafts are sunk. The length of the whole of these shafts together, it is calculated, is more than twelve miles in perpendicular depth, and if to these are added the horizontal galleries, which perforate the hill in all directions, the extent of subterranean excavation is upwards of sixty miles.