Thus it will be seen that the Indian measurements constituted a statement of dimensions primarily useful to the builder, for their main purpose was to fix the proportions rather than establish the actual length, width, and depth. Today we state the length of a canoe in terms of extreme overall measurement; the Indian was inclined to state the length in building terms, giving dimensions applicable to the woodwork only, just as the old-time shipbuilder gave the keel length of a vessel instead of the overall length on deck. The building site was carefully selected. The space in which the canoe was to be set up had to be smooth, free of stones and roots or anything that might damage the bark, and the soil had to be such that stakes driven into it would stand firmly. A shady place was preferred, as the bark would not dry there as fast as in sunlight. Since the construction of a canoe required both time and the aid of the whole Indian family, the site had to be close to a suitable place for camping, where food and water could be obtained. It is not surprising, therefore, to find canoe building sites that apparently had been used by generations of Indians. The preparation of the building bed was controlled by the intended form of the canoe to be built. If the bottom of the canoe was to be rockered, the cleared ground was brought to a flat surface for the length required for setting up the canoe. If the rocker was to be great, the middle of the bed would be slightly depressed. If the bottom was to be straight fore-and-aft, or very nearly so, the bed was crowned from 1½ to 2 inches higher in the middle than at the ends, so that the canoe was first set up with a hogged bottom. Very large canoes such as were used in the fur trade required as much as 4 inches crown in the building bed. Other dimensions being equal, the amount of crown was usually somewhat greater in canoes having bulging sides than in ones having more upright or flaring sides. Canoe factories such as were operated in certain fur-trading posts sometimes had a plank building bed suitably crowned and drilled for setting the stakes. Two methods of setting up the canoe were used. In most of the eastern area, the gunwales were put together and used to establish the plan outline of the canoe on the building bed. But a building frame was used for constructing the various narrow-bottom canoes having flaring sides, and for some other tribal forms. The frame, made in the same general form as the gunwales when assembled, but less wide and sometimes much shorter, could be taken apart easily, allowing it to be removed after the canoe was built; hence it could be used to build as many canoes as desired to the same dimensions as the first, and was retained by the builder as a tool, or pattern, for future use.