"They're named after the hides of the bull buffalo, which are used for the covering," explained the captain. "First a bundle of rather heavy willow poles are fashioned into a bottom and bound together with rawhide. To this other and more slender willow poles are fastened by their smaller ends and curved up and out to make the ribs. Then two heavy poles are bent on each side from stem to stern and lashed to the ends of the ribs, forming the gunwale. Everything is lashed with rawhide and not a bolt or screw or nail is used. Hides of buffalo bulls, usually prepared by the Indians, although the hunters and trappers can do the work as well, are sewn together with sinew after being well soaked. They are stretched tightly over the frame and lashed securely to the gun'le, and they dry tight as drumheads and show every rib. Then a pitch of buffalo tallow and ashes is worked into the seams and over every suspicious spot on the hides and the boat is ready. Usually a false flooring of loosely laid willow poles, three or four inches deep, is placed in the bottom to prevent the water, which is sure to leak in, from wetting the cargo. In the morning the boat rides high and draws only a few inches of water; but often at night there may be six or eight inches slopping around inside. I doubt if any other kind of a boat can be used very far up on the Platte, and sometimes even bullboats can't go up." "How was it that the fur company's boat was tied at the levee at St. Louis, after we left?" asked Tom. "Rather late for her, isn't it?" "Yes, it is," answered the captain. "The great event on this river has always been the annual upstream fur packet. She is coming along somewhere behind us, and very likely will pass us before we reach the mouth of the Kaw. They take bigger chances with the river than we do because they've got to get up to Fort Union and away again while there's water enough." He looked at Patience. "Are you going far, Miss Cooper?" he asked, anxious to get the conversation into channels more to his liking. "Santa Fe, captain," she answered as placidly as though it were a shopping trip from her home to the downtown stores of St. Louis. "Well, well!" he exclaimed, as if he had not known it. "That will be quite an undertaking!" Tom Boyd was staring at her aghast, doubting his ears. The slowly changing expression on his face caught her attention and she smiled at him. "You look as if you had seen a ghost, Mr. Boyd," she laughed. "I'm going to do my very best not to see one, Miss Cooper; or let anyone else see one," he answered mysteriously. "I am glad that I, too, am bound for Santa Fe. It is a great surprise and pleasure to learn that you are going over the same trail." "Why, didn't you say that you were going over the Oregon Trail this year?" she quickly asked. "At least, I understood you that way."