OTHER RESOURCES OF MICHIGAN 113 



for several years preceding. Drain tile were also 

 manufactured of a value of $734,012. The figures 

 for 1916 show also 5,539,000 vitrified bricks pro- 

 duced, valued at $80,915. In addition there were 

 small amounts of fire-proofing and hollow building 

 tile or blocks.^ There has been a steady increase in 

 the production of pottery, which, in 1917, amounted 

 to $1,187,981, attributed to the increased output 

 of porcelain and decorated ware, and porcelain 

 sanitary and electrical supplies. The manufacture 

 of flower-pots is an important element in this total, 

 and other items include clay pipes, crucibles, spark- 

 plugs and insulators. ]\Iichigan clays are employed 

 in the manufacture of flower-pots, but imported clays 

 for porcelain pipes and other white ware, since 

 Michigan lacks kaolin for this purpose.^ The brick- 

 making and related industries are confined very 

 largely to the southern half of the Lower Peninsula 

 where suitable raw material is available. "Wayne 

 County, where lake clay is abundant, is a particularly 

 important center for the manufacture of common 

 bricks. The Michigan Geological Survey has stated 

 that most of the surface clays in IMichigan are of low 

 grade, and, due to their sandy or calcareous nature, 

 most of these chiys are adapted for making only 

 common brick and tile or low grade pottery.^ Ex- 

 posures of clay or shale beds suitable for the manu- 



* "Production and Value of Mineral Products in Mich- 

 ifran," 1917, 153-154. 

 Ubid., 155. 

 Ubid., 151. 



