were sunk into mounds of pre-existing prehistoric domestic waste known as middens. This provided the houses with a stability and also acted as insulation against Orkney's harsh winter climate. On average, each house measures with a large square room containing a stone hearth used for heating and cooking. Given the number of homes, it seems likely that no more than fifty people lived in Skara Brae at any given time. It is not clear what material the inhabitants burned in their hearths. Childe was sure that the fuel was peat, but a detailed analysis of vegetation patterns and trends suggests that climatic conditions conducive to the development of thick beds of peat did not develop in this part of Orkney until after Skara Brae was abandoned. Other possible fuels include driftwood and animal dung. There is evidence that dried seaweed may have been used significantly. At some sites in Orkney, investigators have found a glassy, slag-like material called "kelp" or "cramp" which may be residual burnt seaweed. The dwellings contain a number of stone-built pieces of furniture, including cupboards, dressers, seats, and storage boxes. Each dwelling was entered through a low doorway that had a stone slab door which could be shut "by a bar that slid in bar-holes cut in the stone door jambs." A number of dwellings offered a small connected antechamber, offering access to a partially covered stone drain leading away from the village. It is suggested that these chambers served as indoor privies. Seven of the houses have similar furniture, with the beds and dresser in the same places in each house. The dresser stands against the wall opposite the door, and was the first thing seen by anyone entering the dwelling. Each of these houses had the larger bed on the right side of the doorway and the smaller on the left. Lloyd Laing noted that this pattern accorded with Hebrides custom up to the early 20th century suggesting that the husband's bed was the larger and the wife's was the smaller. The discovery of beads and paint-pots in some of the smaller beds may support this interpretation. Additional support may come from the recognition that stone boxes lie to the left of most doorways, forcing the person entering the house to turn to the right-hand, "male", side of the dwelling. At the front of each bed lie the stumps of stone pillars that may