About the middle of the northern half of the log-pavement was found a remarkable series of four hearths, or fire-places, superimposed one above the other. The lowest was placed a little above the log-pavement, and had a layer of stones, clay, and earth intervening between it and the wood. About one and a half foot higher there was a second hearth; at a similar interval, a third; and at 2½ feet still higher, a fourth. These hearths were formed of small boulders laid closely together, like a stone causeway, embedded in, and surrounded by, a layer of clay (=Fig. 139=). They were oval or circular in shape and about four feet in diameter. The corresponding layers of clay extended considerably beyond the limits of the hearths around which they appeared to form a flooring. The third hearth (counting from below upwards) had been more elaborately constructed than the others, and it was surrounded by a number of stumps of stout uprights which no doubt were the remains of a secondary building, as their lower ends did not penetrate much beyond the level of the hearth. The space underneath the clay bed corresponding to this hearth, and extending downwards to the log-pavement, was, next to the refuse heap, the most prolific in relics. In it were found, about the level of the second fire-place, nearly the entire skeletons of two animals like a goat or sheep, the skulls of which had short horn-cores attached to them. _Gangway._--Beyond the midden, outside the island, the tops of a few piles were detected, and upon making exploratory excavations, these turned out to be the remains of a gangway. As this structure was very peculiar and somewhat comparable to the wooden structures described by Virchow and others in the German Pfahlbauten, I will here quote my original description of it _in extenso_. (See plan and sections, facing page 416):--