ILLUSTRATIONS 



Plate I 



Fig. 1. Bricks manufactured from Iwahig clay: 



Nos. 1 and 2 manufactured at Iwahig by the soft-mud, direct- 

 press process. 

 Nos. 3 and 4 manufactured at the Bureau of Science by stiff-mud 



processes. 

 Nos. 5 and 6 show effects of nodules of calcareous material in 



the clay. 

 No. 7 shows smooth surfaces obtained when nodules of calcareous 



materials are pulverized. 

 No. 8. Floor tile. 

 2. The raw materials and natural cement products obtained by the 

 artificial process of manufacture. 



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