ILLUSTRATIONS. 



Pago. 



PLATE I. Fig. 1. Raw clay. Fig. 2. Burnt clay 16 



TEXT FIGURES. 



FIG. 1. Ball mill 6 



2. Briquette die . . . : 7 



3. Briquette machine 8 



4. Impact machine to determine cementing value of rock 9 



5. Diagram showing point of failure in cementation test 10 



6. Diagram showing prolonged effect of water on cementing value 13 



4 



