134 GEOLOGY OF ILLINOIS. 



making the white brick at Woodstock, is used also for the manufacture of drain 



O ' 



tile, and is said to answer well. 



Lime is burned from the limestone boulders, which are abundant in many 

 parts of the district, and has also been manufactured from some of the limestone 

 outcrops, but no very extensive manufacture of it has been attempted in either 

 of the two counties. Sand and gravel, for mortar and concrete, are generally 

 sufficiently abundant in all parts of the district. 



Peat. This material is found, in a greater or less extent, in all parts of the 

 district, but the most extensive deposits are found in its northern half. The 

 different bogs or sloughs in which these deposits exist, are so numerous and scat- 

 tered that it is difficult to give more than an approximate estimate of the area 

 they occupy. Perhaps, taken altogether, four or five thousand acres would be 

 a sufficiently low estimate. Only a few of the sloughs have been at all exam- 

 ined as to the quality and depth of the beds. 



One of the largest of the sloughs is that which may be seen in sections 7 

 and 8, township 46, range 7, a little north and northeast of Hebron station on 

 the Rockford and Kenosha division of the Northwestern railway. From this 

 point it extends, with some interruptions, several miles in a general southwest 

 direction to the Nippersink, and probably occupies altogether an area equal to 

 two or three square miles. The depth, when I was able to observe it, averaged 

 from six to ten feet; the peat ranging from a light, fibrous substance, of a red- 

 dish brown color, to a denser dark colored material, of a considerable specific 

 gravity, when dried. 



Most of the other sloughs are of comparatively small size, varying from one 

 to two or three hundred acres in extent. In the eastern part of Lake county, 

 the low and marshy tract along the shore of Lake Michigan, north of the city 

 of Waukegan, includes in its area a large proportion of peat bog, much of it 

 of considerable depth. A very large proportion of the area in the district, now 

 occupied by these deposits of peat, is so situated as to be capable of drainage, 

 and nearly all can be made use of to a greater or less extent for the purpose of 

 pasturage, etc. 



In regard to the value of the material as an article of fuel, we have the tes- 

 timony of those who have used it, generally in its favor. It has been used to a 

 considerable extent in the brick and tile works of E. B. Durfee, Esq., at Wood- 

 stock, both in the kilns and in the furnace of a stationary steam engine, and in 

 both cases is reported to have given entire satisfaction. I am not aware of its 

 having been made use of for these purposes at any other place in the district, 

 but it has been used, to a greater or less extent, for domestic firing, in various 

 parts, and is generally said to answer well. It use, however, in most places, has 

 been only experimental as yet, and it will probably be a long time before it will 

 come into general use as a fuel, even in limited districts. In some portions of 



