He went from house to house and ordered his people to clean up their back yards, to ventilate their houses, to bathe and be decent and orderly. He devised a system of sewerage, and utilized the belfry of his church as a water-tower so as to get a water pressure from the little stream that ran near the town. The remains of this invention are to be seen there in the church-steeple even unto this day. King Sigismund of Poland had heard of the attacks made by Copernicus upon the alchemists, and sent for him that he might profit by his advice, for it seems that the King, too, had been having experience with alchemists. In their seeking after a way to make gold out of the baser metals they had actually succeeded. At least they said so, and had made the King believe it. They had shown the King how he could cheapen his coinage one-half, and "it was just as good!" The King could not tell the difference when the coins were new, but alas! when they went beyond the borders of Poland they could only be passed at one-half their face-value; travelers refused to accept them; and even the merchants at home were getting afraid. Copernicus analyzed some of this money made for the King by his alchemist friends and found a large alloy of tin, copper and zinc. He explained to the King that by mixing the metals they did not change their nature nor value. Gold was gold, and copper was copper--God had made these things and hid them in the earth and men might deceive some men--a part of the time--but there was always a retribution. Debase your currency, and soon it will cease to pass current. No law can long uphold a fictitious value. The King urged Copernicus to write a book on the subject of coinage. The permission of the Pope was secured, and the book written. The work is valuable yet, and reveals a deep insight into the heart of things. The man knew political economy, and foretold that a people who debased their currency debased themselves. "Money is character," he said, "and if you pretend it is one thing, and it turns out to be another, you lose your reputation and your own self-respect. No government can afford to deceive the governed. If the people lose confidence in their rulers, a new government will spring into being, built upon the ruins of the old. Government and commerce are built on confidence." Then he went on to show that German gold was valuable everywhere, because it was pure; but Polish gold and Russian gold were below par, because the money had been tampered with, and as no secrets could be kept long, the result was the matter exactly equalized itself, save that Russians and Polanders had in a large degree lost their characters through belief in miracles. Copernicus advocated a universal coinage, to be adopted by all civilized nations, and the amount of alloy should be known and plainly stated, and this alloy should simply be the seigniorage, or what was taken out to cover the cost of mintage.