LAGL'NA CLAYS. 

 Physical properties of the clay from the left iank. 



381 



Water 

 added to 



give a 

 workable 



paste 

 (per cent 



total 

 weight). 



Tensile strength. 











1 



Air dried. 



Burned. 







Kilos 

 per 

 square 

 centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Kilos 



per 



square 



centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Air. 



Fire. 



Total. 



Air dried. 



Burned. 



37.0 



1.9 



a 27 



none. 



'none. 



8.65 



17.5 



26.15 



Yellowish-gray.._ 



Red. 



* 8 of the 9 briquettes .were so badly cracked that they were not usable, 

 b Cracks open in all directions and the briquettes warp badly. 



Physical properties of the clay from the right hank. 



Water 

 added to 



give a 

 workable 



paste 

 (per cent 



total 

 weight). 



Tensile strength. 













Air dried, 2 de- 

 terminations 

 averaged. 



Burned. 



Shrinkage (per cent). 



Color. 



Kilos 

 per 

 square 

 centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Kilos 



per 



square 



centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Air. 



Fire. 



Total. 



Air dried. 



Burned with 



free access 



of air. 



30.0 



1.55 



22 



none. 



onone. 



8.5 



14.8 



23.3 



Gray 



Red. 









" Cracks open in all directions and the briquettes warp badly. 



The red color of the burned product and the abnormally great fire 

 shrinlcage indicate that this clay is worthless for the manufacture of fired 

 products, furthermore the product cracks badly upon air drying. 



BOTOCASr. 



There is a peculiar ridge of red clay which is said to extend nearly 

 all the way from Lucban to Pagsanjan. As it exists in such large 

 quantities I thought it might be of commercial value and a small sample 

 was taken about a hundred meters south of the barrio of Baquio. Its 

 analysis and physical properties are as follows: 



Chemical analysis. 

 [Figures give percentages.] 



Silica 

 (SiOo). 



Alu- 

 mina 

 (AI2O3). 



Fluxes. 



Loss on 

 igni- 

 tion." 



Water 

 (H2O) 

 below 

 110°. 



Tita- 

 nium 



oxide. 



(TiO„). 



Manga- 

 nese 

 oxide 



(MnO). 



Total 

 iron giv- 

 en as fer- 

 ric oxide 

 (FeoOa). 



Lime 

 (CaO). 



Magne- 

 sia 

 (MgO). 



Soda 

 (Na.O). 



Potash 

 (K,0). 



34.55 

 "38.4 



28.73 

 >'31.9 



12.77 

 >|14.2 



0.00 

 1-0.00 



0.16 

 kO.lS 



small, 

 "small. 



small, 

 "small. 



13.02 

 "14.47 



10.09 

 "0.00 



1.17 

 "1.30 



0.06 

 "0.07 



" Mostly water above 110° 

 75034 6 



" Recalculated free from water below 110 ° . 



