Mineralogical Description of the Island of Banka. 97 



which runs off from the central range and forms the point Tan- 

 jong Mantling. Hence I proceeded in a northern direction to the 

 district of the mines. 



On leaving the stockade a long extended hill is observed to- 

 wards the central parts of the peninsula, which was pointed out 

 to me as Gunung Panjie (or Pantjie), beyond which the highest 

 parts of the Gunung Towing are occasionally observable stretch- 

 ing towards the southeast. 



The road on leaving the stockade is slightly ascending, and 

 the country soon becomes waving. About a mile north of the 

 stockade I observed the first granite rocks : they soon became 

 numerous on both sides of the road, and some of them were of 

 considerable size. One in particular attracted my notice. It 

 stood alone, the form was irregularly conical, the top tabular, and 

 the sides, about half way down, regularly excavated by the grad- 

 ual operation of the descending water after rains. 



Most of these rocks, like those at Mampang, were porphyritic 

 with teldspar in large parallelograms and squares. On several parts 

 of the road I found loose rounded fragments of red ironstone, sim- 

 liar to those collected in the alluvial districts above mentioned, 

 but I remarked none in situ. 



The district of the mines is situated north of the stockade : 

 they have been worked for many successive years, and extensive 

 surface^remain exposed. 



The mine at present worked is at Towallam : the pit was reg- 

 ularly oblong. I noticed at different sides the following strata. 



In the south, 



1. Stratum, vegetable mould, 



2. Black clay, massive as observed in the other mines, 8 



3. Clay of a grayish color containing a small propor- 

 tion of sand, . - . - . 4 



l£fec 



4. Black clay, irregular massive, *v . 6 



5. Coarse sand in transparent grains imbedded in pure 



.. 



a 



white clay, 



3 



u 



This extended to near the stratum containing the ore of tin* 

 One of the miners with a long crowbar raised a portion of it and 

 obtained for me some of the ore of tin : they were employed in 

 carrying out the last mentioned stratum. 



In the west, 



1. Stratum, vegetable mould. — 2. Black clay, mnssive. — 3- 

 ^and in clay of a gray color. — 4. White sand. — 5. Beautiful 

 white sand (of transparent siliceous particles) and clay. — 6. Sand 

 imbedded in yellow clay. — 7. Sand in dark bluish clay. The 

 last three layers were less regularly horizontal in their disposition 

 than the layers of sand in many other mines : they had consid- 

 erable inclination. — 8. Loose white sand. — 9. Yellow sand, col- 



Sxcg*d Series, Vol. VII, No. 19.— Jan., lb -^ *i'> 



