After concluding my expeditions to the lands and ponds of the beavers, I went to that part of Michigan where the ancient mining pits and trenches have been discovered. The earliest knowledge of them was obtained by an American explorer who, in the year 1847, when seeking for indications of metal ore, noticed several depressions in the ground, and saw lying in a heap, near what seemed to be an ancient excavation, a number of rude stone hammers that he thought had probably been used by hand. In the following year another excavation was discovered, and after clearing this out to a depth of eighteen feet, there was found a detached mass of copper weighing over six tons which rested upon oak sleepers, and beneath it there was a vein of copper five feet thick. There were also several stone hammers, grooved for the purpose of having handles attached to them, and a copper chisel with a socket for a wooden handle, a fragment of which although much decayed, was still in its place. In an adjoining pit at a depth of ten feet, there was a wooden bowl and some charcoal.[11] In some workings, subsequently discovered upon Isle Royale and near the end of the Kee-wai-wona promontory, a number of wooden wedges were seen, together with traces of extensive trenches. In consequence of these discoveries further investigations were made, and a large number of ancient pits were found in the forests, especially in the districts where are now placed the towns of Ontonagon and Houghton. It was within a few miles from the latter town, that the explorers observed the heap of stone hammers, and their attention was directed to the fact that they had been preceded in the search for copper by men of some unknown race, who possessed capacities for mining operations greater than could be attributed to the Chippewas who then occupied the land. In order to examine this heap I engaged a man—who knew the mining and forest region—to guide me to the spot where the hammers still remained. After crossing the Portage Lake and passing over some low neighbouring hills, we came to a depression in the ground which looked like an old ditch or trench. At the side of this ditch, I saw several hundreds of rounded water-worn stones of various sizes. These had evidently been chosen on account of the convenience of their shape, for the purpose of being used for crushing the rocks that contained metal. A few of the stones appeared to have been partly shaped by hand, but the majority of them were in their natural form. Several were perforated by small round holes, caused probably by the action of water. Some men who happened to be employed at one of the mines in the neighbourhood, told me that in their opinion they had been made for thumb holes. They were, however, much too small for such a purpose.