bmmonb.] CHICAGO TO THE MISSISSIPPI RIVER. 299 



beyond they arc numbered from Twelfth upward to Ninety-fifth street, 

 which runs through South Chicago. The area covered by the named 



streets and by the nine principal north and south streets or avenues, 

 next west ward from Lake Park, comprises the principal business portion 

 of the city, in which are its most imposing buildings. It is inclosed on 

 the north and west by the so-called Chicago River, an inlet of the lake, 



which has been artificially deepened and connected with the Illinois 

 and Michigan Canal. This runs southwest ward into the Illinois River, 

 so that the overflow of Lake Michigan through it reaches the Mississippi 

 Biver, The site of this portion of the city was originally only about 7 

 feel above the lake level, but was artificially raised in 1885 to 14 feet. 



The great fire of 1871, which started among wooden buildings in the 

 western portion of the city under the inlluencc of a strong southwest 

 wind, destroyed nearly every building over an area of 2,124 acres (858 

 hectares), in less than twenty- four hours. This area included a great 

 part of the massive buildings of stone and brick in the business center 

 of the city, so that it is estimated that the value of the buildings alone 

 that were destroyed was $53, 000,000, while the total loss was *10G,000,- 

 000. It was rapidly rebuilt, and the enormous blocks which have 

 risen over the burnt district are among the finest specimens of commer- 

 cial architecture in the country. 



Chicago's water supply is mainly obtained from Lake Michigan, 

 though artesian water is also used. Lake .Michigan water is pumped 

 through two tunnels <>o twt below the shore level and extendinc L' 

 miles out into the lake, where they connect with a vertical iron cylinder 

 04 feet (1!) m.) high, inclosed in a crib of iron and wood loaded with 

 stone. The water capacity of these tunnels is 150,000,000 gallons 

 (050,000,000 liters) per 24 hours. 



Chicago has spread rapidly, especially in the last decade, out onto 

 the surrounding prairies, where enormous manufacturing and com- 

 mercial establishments form small cities within themselves. Such are 

 the great Onion stock yards, the Pullman works, etc. It has also 

 provided liberal breathing space for its rapidly-rowing population in 

 an elaborate system of parks. Six of these cover from ISO up to 590 

 acres (44 to 240 hectares) each, besides which are numerous open squares 

 and smaller parks within the older portions of the city. 



From Chicago to Milwaukee the route lies parallel to the shore of 

 Lake Michigan, and within the area of lacustrine deposition of the 

 Champlain epoch, wImmi the boundaries of lake Michigan were much 

 extended. Along this line the Champlain deposits reach westward 8 to 

 11' Dttiles(13 to 19 km.) from the lake. The deposits immediately along 

 the line of the railway are the "gray pebble clays" of the Wisconsin 

 geological survey. The whole of tl>is region is underlain by Niagara 

 limestone. 



