386 



cox. 



Physical properties. 



Water 

 added 

 to give 

 a work- 

 able 

 paste 

 (per 

 cent 

 total 

 weight) . 



1 



Tensile strength. 



Shrinkage (per cent). 



Color. 



Air dried, i de- 

 terminations 

 averaged. 



Burned," 3 de- 

 terminations 

 averaged. 



Air. 



Fire at 

 cone 

 No. 9. 



Total. 



Air dried. 



Burned with 



free access 



of air. 



Kil9s 

 per 

 square 

 centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



Kilos 



per 



square 



centi- 

 meter. 



Pounds 



per 

 square 

 inch. 



25.4 



3.78 



53.8 



4.00 



57 



3.06 



11.1 



14.16 



Creamy-white. 



Rose-cream. 



" Crackles to a certain extent. 



Another and larger opening about ten meters from this and about 

 three or four, meters higher was also sampled. This pit had been Inir- 

 rowed out in every direction to a depth of 3 meters. I excavated a third 

 meter and bored still a fourth to obtain my sample. It was an average 

 of the run of the deposit and showed more red streaks than the former 

 sample and had an extremely mottled appearance. In this pit the natives 

 sorted and discarded the less plastic lumps. The tensile strength of my 

 sample will be seen to be lower than that obtained from the other pit, but 

 it is believed that the clay removed by the carriers was of about the 

 same quality. 



The data and results of the laboratory tests are as follows : 



Chemical analysis. 

 [Figures give percentages.] 



Silica 

 (SiO,). 



.\lumina 

 (ALOa). 



Fluxes. 



Loss 

 on igni- 

 tion." 



Water 

 (H.0) 

 below 

 110°. 



Tita- 

 nium 

 oxide 



(TiOo). 1 



Total 



iron 



given 

 as ferric 



oxide 

 (FeoOa). 



Lime 

 (CaO). 



Mag- 

 nesia 

 (MgO). 



Soda 

 (NajO). 



Pota.* 

 (KoO). 



43.28 

 »43.7 



37.85 

 i>38.2 



3.39 

 i'3.4 



0.08 

 I'D. 08 



0.04 

 ''0.04 



small, 

 t small. 



small, 

 'small. 



14. 2 

 i>14.3 



0.89 

 »0.00 



1.25 

 i'1.25 



■ Mostly water above 110°. 



" Recalculated free from water below 110°. 



