620 NEW YORK STATE MUSEUM 



Massachusetts^ 



The clays are mostly Quaternary, suitable for brick manufac- 

 ture, and are extensively dug around Boston for brickmaking. 

 Kaolin is mined at Blandford, and in tbe western part of the state 

 buff burning clays occur which are adapted to the manufacture of 

 buff brick and terra cotta: 



Refractory wares and art pottery are made near Boston from 

 clays mined in other states. 



Michigan'^ 



The clay-working industry of Michigan has not been developed 

 to any extent except in the line of common brick manufacture. 

 Much of the state is covered with glacial drift; local beds of clay 

 are found in connection with this. In this glacial formation the 

 lowest is the blue gravely clay from 7 to 12 feet thick, which is 

 utilized at Springswell, near Detroit, also in Ottawa, Allegan and 

 BaiTy CO. The products of this clay are red, sand-molded, 

 white, machine-pressed, red, machine-pressed, and sewer bricks. 

 The clays of the extreme northern part of the lower peninsula of 

 Michigan have too much lime to be of any great commercial value, 

 but are used locally to some extent. 



At Coldwater all the clays are used for cement manufacture. 

 Ship clay is found at Rockland and Luther. 



The shales associated with the coal seams are suitable in, many 

 cases for making paving brick or stoneware, and some may be semi- 

 refractory. 



Mississipjn 



The Eocene and Miocene are the most important clay-producing 

 horizons in this state but beds of good quality also occur in the 

 Carboniferous and Cretaceous. The clays have been but little used 

 except for the manufacture of common brick and the lower grades 

 of pottery. (Geology of Mississippi. 1860) 



1 C. L. Whitilt-. "Clay industry of Massachusetts." Min. Ind. 7: 125. 

 * E. and M. J. 29 Auj?. 18./8. Also paper on Michigan 8hal*-s by H. Ries in 

 Michigan ttiiner for lt9U. 



