204 GEOLOGY OF ILLINOIS. 



its yield of ash was very much greater, being from six to eight per cent., while 

 that of the lower seam is from one to three per cent. 



BricJc. There are several large brick-yards near Morris, which manufacture 

 brick from the decomposed shales which overlie the lower coal. As these beds 

 contain considerable calcareous matter, the brick arc not very firm, and do not 

 stand the weather well. It would appear probable that the fire clay below the 

 coal would make a better article. This has not been tried at Morris, but at the 

 Gardner coal shaft the manufacture has been recently commenced. The fire 

 clay, and soft clay shales underlying it, are said to be thirty-five feet deep, and 

 so much of these beds as may be convenient, in mining the coal, is dug out and 

 used promiscuously. Without thorough grinding, therefore, in the pug-mill, 

 the bricks are variable in character and irregular in burning. 



Potter's Clay. The only bed known and worked, is that previously noticed, 

 as occurring near the west end of Goose lake, and extensively used, at Jug- 

 town, in the manufacture of a good grade of domestic earthenware, together 

 with drain-tile and sewer-pipes. The bed consists of more or less thoroughly 

 decomposed clay shale and fire clay of the Coal Measures, containing many 

 fragments of coal, thoroughly mingled, and deposited in a low part of the old 

 river channel, which contains Goose lake, by the current of the river which 

 formerly flowed there. The mixed character of the materials has given much 

 trouble to the potters. The bed has been worked to a depth of about fifteen 

 feet. 



Building Stone. The only considerable source of building stone in this 

 county is Waters's quarry of Trenton limestone, in Saratoga, about four miles 

 northeast of Morris. This yields an abundance of a light gray or drab, massive 

 limestone, which has been extensively used for foundation walls, and in a few 

 cases also for the superstructures. It appears fitted to stand the weather as 

 well as any ordinary stone. It is said to dress well. 



The Cincinnati group, along the AuSable creek, near the county line, yields 

 small quantities of stone for wells and foundations, but nothing suitable for su- 

 perstructures. Beds of the same group upon the northern side of Goose Lake, 

 have been quarried slightly, for similar purposes. 



Upon the bank of Waupecan creek, in the southeast quarter of section 18, 

 township 33 north, range 7 east, Mr. Starr has quarried small quantities of a 

 very solid limestone, No. 6, of the Waupecan section, as given above. 



A sandstone, representing Nos. 1 and 3 of the same section, has been quar- 

 ried to some extent for foundations, on the upper part of the stream, at Hog- 

 grove quarry, and has given good satisfaction ; though where exposed to the 

 weather, it crumbles rapidly. The same defect exists in the sandstone of Pine 

 Bluff. 



