332 REPORT OF NATIONAL MUSEUM, 1899. 



ware, 1 Maryland, and Virginia. The New Jersey beds are very exten- 

 sively utilized in Middlesex County and fully described in the State 

 Geological Reports. 2 . 



As described, the entire plastic clay formation consists of several 

 members as below, arranged in a descending series: 



Feet. 



(1) Dark-colored clay (with beds and laminee of lignite) 50 



(2) Bandy clay, with sand in alternate layers 40 



(3) Stoneware clay bed - 30 



(4) Sand and sandy clay (with lignite near the bottom) 50 



(5) South Amboy fire-clay bed 20 



(6) Sandy clay (generally red or yellow) 3 



(7) Sand and kaolin 10 



(8) Feldspar bed 5 



(9) Micaceous sand bed 20 



(10) Laminated clay and sand 30 



(11) Pipe clay (top white) 10 



(12) Sandy clay (including leaf bed) 5 



(13) Woodbridge fire-clay bed 20 



(14) Fire-sand bed 15 



Raritan clay beds: 



(15) Fire clay 15 



(16) Sandy clay 4 



(17) Potters' clay 20 



Total 347 



The following section of the Coal Measure clays at St. Louis, as pub- 

 ilshed in Bulletin No. 3 of the Geological Survey of Missouri, will 

 serve to show the alternating character of these beds, and their vary- 

 ing qualities as indicated by the uses to which they are put. 3 



(1) Loess, 20 feet. 



(2) Limestone (Coal Measure), 5 feet, 



(3) Clay, white and yellow, used for sewer-pipe manufacture, called "bastard fire 

 clay," 3 to 4 feet. 



(4) Clay, yellow and red, sold for paint manufacture and for coloring plaster and 

 mortar, called "ochre," 3 feet. 



(5) Clay, gray to white, used for paint manufacture and filling, 1 foot 6 inches. 



(6) Pipe clay, variegated, reddish brown and greenish, called "keel," 12 feet. 



(7) Sandstone. 



(8) Slaty shale. 



(9) Coal. 



(10) Fire clay, becoming sandy toward the base. 



When first mined these Coal Measure clays are usually very hard, 

 but on exposure to the weather slack and fall into powder. They are 



l This of course does not include the kaolin deposits of Hockessin, Newcastle 

 County, and similar deposits. 



2 Report on Clay Deposits of Woodbridge, South Amboy, and other places in New 

 Jersey, 1878. 



3 Bulletin No. 3, Geological Survey of Missouri, 1890. 



