LAGL'NA CLAYS. 

 Physical properties. 



385 



Water 

 added 

 to give 

 a work- 

 able 

 paste 

 (per 

 cent 

 total 

 weight) . 



Tensile strength. 



Shrinkage (per cent). 



Color. 



Air dried. 



Burned." 



Air. 



Fire, at 

 cone 

 No. 9. 



Total. 



Air dried. 



1 



Burned with 



free access 



of air. 



Kilos 



per 



square 



centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Kilos 



per 



square 



centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



36. S 



2.71 



38.6 



3.5 



50 



3.06 



7.64 



10.7 



Light cream. 



Light creamy- 

 white. 



" Burns excellently. 



The deposits were being worked on the other side of the Pajo River 

 at the time of my visit; the product is sacked and carried on the backs 

 of natives or ponies to the barrio of Bukal on the lalve shgre where it is 

 made into balls and shipped to Manila. The material as mined is more 

 or less streaked with red, but when the less plastic lumjjs are discarded 

 and when macerated it works np to a light cream and is bought by 

 the Chinese of Binondo, who make of it a sort of whitewash which is 

 said to be better than the whiter product above mentioned, perhaps 

 because of its greater tensile strength. Certain of the physical proper- 

 ties, especiall)' the behavior under the, have no significance when a 

 material is used for covering walls. The open workings indicate a 

 considerable amount of this class of clay. Two of the pits were sampled. 

 The lowest opening on the mountain side was carefully cleaned out to 

 a depth of at least two meters and then I took an average sample of 

 the material, which I removed from a meter bore-hole in the bottom. 

 The clay from this pit was accepted by the natives without sorting. 



The data and results of the laboratory tests of the sample are as 

 follows : 



Chemical analysis. 

 [Figures give percentages.] 



Silica 

 (SiOo). 



Alu- 

 mina 

 (AI.O3). 



Fluxes. 



Loss on 

 igni- 

 tion." 



Water 

 (H„0) 

 below 

 110°. 



Tita- 

 nium 

 oxide 

 (TiO.). 



Total 

 fluxes. 



Total 



iron 

 given as 



ferric 



oxide 

 (FeoOs). 



Lime 

 (CaO). 



Magne- 

 nesia 

 (MgO). 



Soda 

 (Na;0). 



Potash 

 (K„0). 



42.23 

 i>43.1 



37.32 

 "38.05 



1.41 

 i'1.44 



0.23 

 '0.23 



0.07 

 '•0.07 



0.11 



fo.n 



0.35 

 bO.36 



1,5.84 

 i>16.14 



1.92 

 kO.OO 



1.00 

 "1.02 



2.17 

 "2.21 



" Mostly water above 110° 



^ Recalculated free from water below 110.' 



