The celebrated _Clay Works_ in the parish of St. Stephen’s are also well deserving of attention; as they are now conducted upon a very extensive scale. In a commercial point of view, the discovery of this clay, or china stone, has been attended with the greatest advantages, besides being the means of affording employment to many men, women, and children. The value of this clay, or china stone, as it is generally called, was accidentally discovered about 60 years ago; since which time, immense quantities have been exported for the porcelain manufactories in Staffordshire and Wales. It is a decomposed granite, the felspar of which has lost its properties of fusibility; but, in the manufacture of china and earthenware, it is of the greatest value. In the manufacture of crucibles at Truro, it has been found of much value. Notwithstanding, however, the great success which has attended the progress of the china stone works, it is to be lamented, the wages allowed to the several persons employed in them, are so trifling. Little occurs to interest the traveller in regard to mines, after leaving St. Austell, until his arrival at Truro. The _Carnon Stream Works_, on the left of the road leading to Falmouth, are the most considerable in the county, and merit particular observation. It is now nearly 40 years since they were first discovered; and the quantity of tin which they have yielded, has proved a golden harvest to the proprietors of them. The works occupy a considerable extent of ground, and appear to have been gained from the sea; the mud and other matter washed down by the stream, having raised a sort of embankment, which, by its continual extension, and some assistance from art, has gradually contracted the boundaries of the tide.[50] The bed of pebbles from which the tin is extracted, is about 30 feet below the surface of the ground, and from four to six feet thick. As a proof that these works must have been known in very early times, a wooden shovel, and picks made of deers’ horns, together with some human bones and skulls, have been found at different periods. Great improvements have been lately made in the works for drawing off the water, and which has also, from the lowness of their situation, been attended with considerable benefit to several other mines in the neighbourhood.