Page:Cornwall; Cambridge county geographies.djvu/97

 MINERALS AND MINING 81 various sizes, from half an ounce to some pounds in weight. Stream tin is the same as shode but smaller in size and arenacious." Polwhele describes an early stream work disclosed about a century ago. The ore was of the purest kind and contained two-thirds metal. The pebbles from which the metal was extracted were in size from sand-like grains to King Edward Mine, Camborne that of a small egg. The depth of the primeval bed was 2O ft. This appeared to have been worked at a remote period, and before iron tools were employed, as large pick- axes of oak, holm, and box were found there. But archaeo- logical research at the period when he wrote was carried on in such a haphazard way that we cannot trust the reports then made, and it is quite possible that the workings were comparatively late, possibly of Mediaeval times. G. c. 6