FOURTH REPORT OF THE DIRECTOR I907 



117 



Contents: 

 Formation : theoretical mechanics 

 a Dynamic factors pertaining 



to the ice body 

 b Factors relating to the drift 



held in the ice 

 c Factors of external control 

 Drumlin forms and observed re- 

 lations 

 Relation to moraines 

 Special features 

 Syracuse island masses 

 Montezuma island groups 

 Nondrumlin areas ; open spaces 



Special features {continued) 

 Channels -among the drumlins 

 Summary 



Age of the drumlins 



Thrust motion of the ground 

 contact ice 



Origin 



Dynamics 



Drumlin forms 



Depth of the drumlin-making ice 

 Drumlins of Ireland 

 Bibliography 

 Index 



7 No. 115 Geology of the Long Lake Quadrangle. By H. P. 

 Gushing. 88p. 20pl. i map. 



Contents: 



Acknowledgment 



Situation and character 



General geology 



Rocks 



Rock structures 



Topography 

 Glaciation 

 Economic geology 

 Petrography of the rocks 

 Index 



8 No. 112 Mining and Quarry Industry of New York. 3d re- 

 port. By D. H. Newland. 82p. 



Contents: 

 Preface 

 Introduction 

 Mineral production of New York 



in 1904 

 Mineral production of New York 



in 1905 

 Mineral production of New York 

 in 1906 

 Iron ore 



Notes on recent mining develop- 

 ments 

 Millstones 

 Mineral paint 

 Natural gas 

 Arsenical ore 

 Carbon dioxid 

 Cement 

 Clay 



Manufacture of building brick 

 Other clay materials 

 New manufacturers of clay ma- 

 terials 

 Pottery 



Clay {continued) 



Crude clay 

 Emery 

 Feldspar 

 Garnet 

 Graphite 

 Gypsum 

 Peat 



Petroleum 

 Pyrite 

 Quartz 

 Salt 



Sand-lime brick 

 Slate 

 Stone 



Granite 



Limestone 



Marble 



Sandstone 



Trap 

 Talc 



Zinc and lead 

 Index 



