iLDEN.] STONE INDUSTRY IK VICINITY OF CHICAGO, ILL. 359 
faarries of the Brownell Improvement Company produce crushed stone 
or macadam containing about 36 per cent of silica, giving it a very 
iurable quality. Their quarries at Gary, 111., on Desplaines River, 
produce a dense, even-grained limestone in little-fractured strata. 
"I Some foundation stone is gotten out, but the rock is rather hard to 
dress. The product is largely crushed stone for paving. 
At the outcrop, 1 mile southwest of Blue Island, considerable rock 
has been removed for foundation stone. It is stated that a bed of 
bluish, impure limestone has been worked here for hydraulic cement. 
Mi'. .1. V. < t >. Blaney reports the following analysis of this limestone: 
Analysis of limestone 1 mile southeast of Blue Island. 
Clay and insoluble matter 4:5. 56 
Carbonate of lime 31. 60 
Carbonate of magnesium 22. 24 
Peroxide of iron 1 . 20 
Soluble silica ' .16 
Alkalies, loss, etc . 1. 30 
Total 100. 06 
At his place about 2 miles southwest of Blue Island, Mr. Henry 
Schwartz has quarried a limited amount of good foundation stone. 
There is abundant rock here, easily accessible. 
The quarry 1 mile west of Elmhurst, on the Chicago and North- 
western Railway, produces crushed stone. 
The quarry of Kogle & Smith, about 3 miles southeast of Elmhurst, 
yields crushed stone. Some building stone is also taken out. 
At the outcrop, 1 mile northwest of Lagrange, on the bank of Salt 
Creek, a quarry has been opened which is turning out crushed stone 
for macadam. 
Mr. Fred Schultz puts out crushed stone and lime from his quarry 
at Lyons. 
At McCook, on the Santa Fe Railway, near the canals, are the quar- 
ries of the Chicago Crushed Stone Company. Rubble for foundations 
is also produced. 
Not all of the rock exposures have been utilized for economic pur- 
poses. The following may be noted as affording productive sites 
should the demand require: One mile northwest of Humboldt Park; 
corner of North Central Park avenue and Humboldt avenue; two 
blocks west of Humboldt Park; in the vicinity of Robey and Twenty- 
third streets; on the lake shore in Windsor Park, at the foot of Chel- 
tenham place; on either side of Railroad avenue, between Ninety- 
fourth and Ninety-fifth streets, and six blocks west, between Ninety- 
fifth and Ninety- sixth streets. 
At " Stony Island " two quarries have produced considerable rock, 
but are now unused. There is abundant rock thinly covered north 
and west of Thornton. Two miles south of Grlenwood and three- 
