The raisers of these refuse mounds were, we may judge, pre-eminently fishers; and not generally fishers of that adventurous kind who seek their treasure in the depths of the ocean. They lived chiefly upon those smaller fish and shell-fish which could be caught without much difficulty or danger. Yet not only on these; for the bones of some deep-sea fish have also been discovered, whence we know that these mound-raisers were possessed of the art of navigation, though doubtless in a most primitive form. Among remains believed to be contemporary with the shell mounds are found canoes not built of planks, as our boats and as most canoes are nowadays, but merely hollowed out of the trunks of trees; sometimes these canoes are quite straight fore and aft, just as the trunk was when it was cut, sometimes a little bevelled from below, like a punt of the present day; but we believe they are never found rounded or pointed at the prow. Here, then, we see another discovery which has been of the greatest use to mankind, whereof the first traces come to us from these northern shell mounds. That ‘heart with oak and bronze thrice bound,’ the man who first ventured to sea in the first vessel, had lived before this time. Whoever he was, we cannot, if we think of it, refuse to endorse the praise bestowed upon him by the poet; it required no mean courage to venture out to sea on such a strange make-shift as was the first canoe. Perhaps the earliest experiment was an involuntary one, made by some one who was washed away upon a large log or felled tree. We can fancy how thence would arise the notion of venturing again a little way, then of hollowing a seat in the middle of the trunk, until the primitive canoes, such as we find, came into existence.