But while Chicago was fast becoming rich and big, it was not a pleasant place in which to live. The site of the city was a low and marshy plain, almost on a level with the lake, and the problems of drainage of such a location had to be met and solved. In the beginning, to keep the houses dry, they were built above the ground and supported by timbers or piles. Cellars and basements were unknown, and the city streets were a disgrace. In spring they were flooded and swimming with mud. Even in summer, pools of stagnant water stood in many places. For years wagons sticking fast in the mud were common sights. Cholera, smallpox, and scarlet fever swept the city again and again. People, knowing only too well that unsanitary conditions brought on these diseases, did their best to remedy matters. They saw that Chicago would be clean and healthy if only they could find a way to carry off her wastes. First they decided to turn the water into the river by sloping all the streets towards it. Then came a severe flood which did much damage and showed the folly of digging down any part of the city. Chicago was too low already. So the people hastened to raise their streets again by filling them in with sand, and this time they made gutters along the side to carry off the water. Heavy wagons soon wore away the sand, however, and the streets were as muddy as before. Finally, an engineer advised the people to raise the whole city several feet; then brick sewers could be built beneath the street to carry the sewage into the river. At first many refused to listen to such a proposal. The undertaking was so great that it frightened them. But as things were, business and health were suffering. Something had to be done, and at last the city determined to raise itself out of the mud, and work was begun. Ground was hauled in from the surrounding country, streets and lots were filled in, the buildings were gradually raised, and sewers were built sloping toward the river. It was a gigantic task and cost years of labor, but when it was done, Chicago was, for the first time, a dry city. It must be remembered that the area of Chicago at that time was but a small part of the present city. Another source of trouble was the drinking-water, which was taken from Lake Michigan. The sewage in the river flowed into the lake and at times contaminated the water far out from the shore, thus poisoning the city's supply. It was therefore decided to build new waterworks, which would bring into the city pure water from farther out in the lake. A tunnel was built, extending two miles under Lake Michigan. At its outer end a great screened pipe reached up into the lake to let water into the tunnel. Over the pipe a crib was built to protect it. On the shore, pumping stations with powerful engines raised the water to high towers from which all parts of the city were supplied. [Illustration: CHICAGO HIGH SCHOOL, 1856]