CONTENTS 



FAGB 



Preface 493 



Origin and nature oi clay 496 



Mineralogy of clays 503 



Properties of clay 510 



Cbemical properties 511 



Methods of analyzing 530 



The rational analysis 533 



Physical propertie.s 53b 



Mechanical analysis 561 



Classitication of clays 564 



Uses 564 



Coloring agents 565 



Geologic distribution 572 



Occurrence in New York state. 572 

 Clays of Champlain valley. 594 



Long Island clays 595 



Staten Island clays, 607 



Occurrence in the United States 61 1 



Clay- working , 628 



Structure of clay deposits .... 628 

 Prospecting and exploring . . . 629 



Methods of working 631 



Purification of clay 633 



Uses of clays 636 



Characters of brick clays 636 



Burning of brick clays 639 



The brickmaking industry 643 



Crushing strength of bricks . . . 647 

 Building brick industry in New 



York state 650 



Methods of manufacturing 653 



Cost of production r , 685 



Detailed account of brick 



yards 686 



Paving brick 743 



Terracotta 758 



General properties 758 



Terra cotta clays 759 



Terra cotta manufacture 761 



Roofing tile , 765 



Sewer pipe 767 



Clays used 767 



Manufacture of sewer pipe . . . 768 

 Drain tile '. 770 



PAGK 



Hollow brick, terra cotta lumber, 

 fireproofing 773 



Floor tile 774 



Decorative tile 777 



Methods of tile decoration 777 



Fire clays .... 781 



Refractory clay products 783 



Manufacture of fire brick 784 



Glass pot clays 786 



New York fire clays 788 



Pottery 791 



Description of different grades. 791 



Methods of manufacture 798 



Methods of decoration 814 



New York stoneware clays. . . . 817 

 Pottery industry of New York. 823 



Shales of New York 825 



Distribution and properties. . ; 826 

 Feldspar and quartz 841 



Minor uses of clays 845 



Portland cement 845 



Mineral paint i 848 



Clarifying oils and fulling 



earth.. 848 



Filling paper 852 



Food adulterants 852 



Ultramarine manufacture.... 852 

 Polishing and abrasive mate-- 



rials '852 



Road materials 853 



Puddle 853 



Testing of clay wares. 854 



Porosity or permeability 854 



Breaking strength 855 



Hardness test 855 



Determination of deleterious 



impurities 856 



Determination of soluble salts. 856 



Resistance to weathering 856 



Resistance to acids 8.^7 



Abrasion test 857 



Sections of clay deposits 858 



Clay analyses 860 



Bibliography of clay literature. . . . 808 



Directory of clay workers in New 

 York state 91S 



Index 927 



