TABLE OF CONTENTS. 



Sieving the product 180 



Analyses of hydraulic limes 182 



Weight and specific gravity 182 



Tensile and compressive strength 183 



Ratio compressive to tensile strength ". 183 



Proportions for mortars and concretes 184 



Grappier cements 185 



Definition 185 



Composition of grappier cements 185 



Physical properties of grappier cements 185 



CHAPTER XV. 



FEEBLY HYDRAULIC LIMES: SELENITIC LIMES. 



Feebly hydraulic limes 187 



General character and index 187 



Analyses of raw material 187 



Analyses of feebly hydraulic limes 188 



Tensile strength 188 



Compressive strength 189 



Selenitic lime : Scott's cement 190 



Composition 190 



Manufacture of selenitic limes 190 



Tensile strength of selenitic limes 191 



Compressive strength of selenitic limes 192 



PART V. NATURAL CEMENTS. 

 CHAPTER XVI. 



DEFINITION AND RELATIONS OF NATURAL CEMENTS. 



Lack of homogeneity in the group 194 



Definition of natural cements 195 



Relations of natural cements to others 195 



Cementation Index of natural cements 196 



Statement of the index 196 



Example of calculation 196 



Basal assumptions 197 



Use of the Cementation Index 198 



Values of the index for natural cements 198 



Subgroups of the class of natural cements 198 



CHAPTER XVII. 



RAW MATERIAL: NATURAL-CEMENT ROCK. 



Composition of natural-cement rock 201 



American natural-cement rocks 201 



