Another problem, found even more serious as the city grew, was the drainage. In former years the sewage was discharged into the Chicago River and Lake Michigan. The river became a most malodorous stream in consequence, and as it had practically no descent, the current would scarcely flow, and the lake, from which the city water-supply was drawn, was more and more polluted. With the customary enterprise of these wonderful people, however, they decided to make the only change feasible, which was to take advantage of the descending watershed towards Desplaines River and change their sewerage system so that it would all discharge in that direction. The problem was solved by the construction of the most expensive drainage works in the world, and a complete change of the sewers, at a cost altogether approximating $40,000,000. St. Louis and the towns along the Desplaines fought the scheme, and there was protracted litigation, but the very existence of Chicago depended on the result. The great drainage canal was completed connecting the Chicago River South Branch with Desplaines River at Lockport, twenty-eight miles southwest, where it discharges the outflow from Lake Michigan, which then flows past Joliet, and ultimately into Illinois River. This huge canal, opened in January, 1900, reverses the flow of the Chicago River, which now draws in about three hundred thousand cubic feet of water per minute from Lake Michigan and flushes the canal, which is also to be made available for shipping. Thus the Chicago River flows towards its source with a free current, and Lake Michigan has been purified. The canal has quite a descent to Lockport, and the water-power is to be availed of in generating electricity. The city water-supply is drawn from cribs out in the lake through four systems of tunnels, aggregating twenty-two miles, furnishing an ample service, and pumping-stations in various locations elevate the water in towers to secure sufficient head for the flow into the buildings. The chief of these towers, a solid stone structure alongside the lake, rises one hundred and sixty feet, the huge pumping-engines forcing a vast stream constantly over its top. [Illustration: _Lincoln Monument, Lincoln Park, Chicago_] FEATURES OF CHICAGO.