There were many places where the keelboat could not be cordelled at all, as along sandbars where the water was too shallow for the boat to get near the shore, or the alluvium too soft for the men to walk in. At such times it was necessary to resort to the pole, as it was called. This was a turned piece of ash wood regularly manufactured at St. Louis. On one end was a ball or knob to rest in the hollow of the shoulder, for the voyageur to push against; and on the other was a wooden shoe or socket. In propelling the boat with these poles eight or ten voyageurs ranged themselves along each side, near the bow, facing aft, pole in hand, one in front of the other, as close together as they could walk. The whole operation was under the direction of the patron. At his command “_A bas les perches_” (down with the poles), the voyageurs would thrust the lower ends into the river close to the boat and place the ball ends against their shoulders, so that the poles should be well inclined downstream. They would all push together, forcing the boat ahead, as they walked along the _passe avant_ toward the stern, until the foremost man had gone as far as he could. The patron then gave the command “_Levez les perches_” (raise the poles), upon which they would be withdrawn from the mud, and the men would walk quickly back to the bow and repeat the operation. All steering was done while the poles were up, for the boat could not change direction while the men were pushing. It was always essential to give the boat sufficient momentum at each push to keep her going while the men were changing position. The _passe avant_ had cleats nailed to it to keep the feet from slipping, and the men, when pushing hard, sometimes leaned over far enough to catch hold of the cleats with their hands, thus fairly crawling on all-fours. In some places where the water was too deep for the poles and where cordelling was impracticable, oars were resorted to. There were five or six of these on each side of the bow. They often furnished assistance also when the boat was being cordelled. [Sidenote: NAVIGATION BY SAIL.]