It was true that he had no receipt for his money, acknowledging that it was the stipulated price paid for a full-grown white maid between eighteen and nineteen years old, with brown eyes, brown hair, twenty-eight teeth, all sound, and a pale complexion; who weighed about two Attic talents and five minæ, and measured just six palms, standing on her bare feet. In strict law, he should have had such a document, signed by the father or mother or owner of the slave, but he knew that he was quite safe without it. Like all Bokharians, he was a profound judge of human nature, and he was quite sure that having once submitted to her fate Zoë would not cheat him by claiming the freedom she had sacrificed; moreover, he knew that the adopted daughter of Michael Rhangabé who had died on the stake in the Hippodrome as an enemy of the reigning Emperor, would have but a small chance of obtaining justice, even if she attempted to prove that she had been carried off by force. Rustan Karaboghazji felt that his position was unassailable as he followed the litter that carried his latest bargain through the winding streets of Constantinople towards the narrow lane, one side of which was formed by that mysterious wall which had but one door in it. He was well pleased with his day's business, for he was quite sure that he had netted a handsome profit. Under his cloak he held a string of beads in one hand, and as he walked he made the calculation of his probable gains, pushing the beads along the string with his thumb. He had paid one hundred and fifty gold ducats for Zoë; but fifty of them were at least a quarter of their value under weight, so that the actual value of the gold was one hundred and thirty-seven and a half ducats. He was quite sure that Zeno would approve the purchase on a careful inspection, and that he would be willing to give three hundred and fifty sequins, though the girl was a little over age, as slaves' ages were counted. She should have been between sixteen and seventeen, yet she was exceptionally pretty, and spoke three languages--Greek, Latin, and Italian. If Zeno paid the price, the clear profit would be two hundred and twelve and a half ducats. The beads worked quickly in Rustan's fingers, and his hard grey eyes gleamed in the dark. Two hundred and twelve and a half on one hundred and thirty-seven and a half, by the new Venetian method of so much in the hundred, which was a very convenient way of reckoning profits, meant one hundred and fifty-four and a half per centum. The beads worked furiously, as the merchant's imagination carried him off into a mercantile paradise where he could make a hundred and fifty per cent on his capital every day of the year except Sundays and high feast days. This calculation was complicated, even for a Bokharian brain, but it was a delightful one to follow out, and Rustan's blood coursed pleasantly through his veins as he walked behind his purchase.