McDonald ushered them into a big square room, where the bales were undone and spread abroad. Deftly, silently the Trader sorted the furs, placing to one side or the other the "primes," "seconds," and "thirds" of each species. For a moment he calculated. Then he stepped to a post whereon hung long strings of pierced wooden counters, worn smooth by use. Swiftly he told the strings over. To one of the Indians he gave one with these words: "Mu-hi-kun, my brother, here be pelts to the value of two hundred 'beaver.' Behold a string, then, of two hundred 'castors,' and in addition I give my brother one fathom of tobacco." The Indian calculated rapidly, his eye abstracted. He had known exactly the value of his catch, and what he would receive for it in "castors," but had hoped for a larger "present," by which the premium on the standard price is measured. "Ah hah," he exclaimed, finally, and stepped to one side. "Sak-we-su, my brother," went on McDonald, "here be pelts to the value of three hundred 'beaver.' Behold a string, then, of three hundred 'castors,' and because you have brought so fine a skin of the otter, behold also a fathom of tobacco and a half sack of flour." "Good!" ejaculated the Indian. The Trader then led them to stairs, up which they clambered to where Davis, the Assistant Trader, kept store. There, barred by a heavy wooden grill from the airy loft filled with bright calicoes, sashes, pails, guns, blankets, clothes, and other ornamental and useful things, Sak-we-su and Mu-hi-kun made their choice, trading in the worn wooden "castors" on the string. So much flour, so much tea, so much sugar and powder and lead, so much in clothing. Thus were their simple needs supplied for the year to come. Then the remainder they squandered on all sorts of useless things--beads, silks, sashes, bright handkerchiefs, mirrors. And when the last wooden "castor" was in they went down stairs and out the picket lane, carrying their lighter purchases, but leaving the larger as "debt," to be called for when needed. Two of their companions mounted the stairs as they descended; and two more passed them in the narrow picket lane. So the trade went on. At once Sak-we-su and Mu-hi-kun were surrounded. In detail they told what they had done. Then in greater detail their friends told what _they_ would have done, until after five minutes of bewildering advice the disconsolate pair would have been only too glad to have exchanged everything--if that had been allowed.