LIST OF ILLUSTRATIONS. 



PAGE 



1. Map of U. S. showing location of gypsum deposits and plaster-plants . . ..Opp. 14 



2. Map of Kansas, showing location of gypsum deposits 19 



3. Map of New York, showing extent of gypsum-bearing formations 20 



4. Map of the gypsum deposits of Ohio 22 



5. Nipper for coarse crushing of gypsum 34 



6. Cracker for intermediate reduction of gypsum 35 



7. Stedman disintegrator, opened 36 



8. Stedman disintegrator, cage construction 37 



9. Construction and setting of gypsum kettles 38 



10. Four-flue kettle, with accessories, dismounted 39 



11. Kettle with sectional bottom 40 



12. Section of 100-ton plaster mill, kettle process 42 



13. Plan of Electric Plaster Co.'s mill, Blue Rapids, Kansas 45 



14. Plan of plaster mill, rotary calciner process 47 



15. Cummer rotary calciner for plaster 48 



16. Broughton mixer 51 



17. Hair-picker 51 



18. Effect of sand on tensile strength of plaster 60 



18a. Effect of sand on compressive strength of plaster , 62 



1 9. Map of the U. S . , showing location of principal lime-producing centers . . Opp. 88 



20. Plan and section of lime kilns 102 



21. Aalborg kiln for lime burning 103 



22. Keystone lime kiln 105 



23. O'Connell lime kiln 107 



24. Eldred lime-hydrating system 125 



25. Campbell lime-hydrater 127 



26. Schwarz drying and mixing machine 137 



27. Kiln used for burning hydraulic lime 178 



28. Section of hydraulic lime plant, Malain, France 181 



29. Tensile strength of Lafarge (grappier) cement 186 



30. Tensile strength of feebly hydraulic limes 189 



31. Tensile strength of plain hydraulic and selenitic limes 192 



32. Compressive strength of " " 193 



33. Map of U. S., showing location of natural-cement plants Opp. 194 



34. Tensile strength of various classes of cement 218 



XXV 



