BY LEO A. COTTON. 775 



kaolinised. This change is connected with the genesis of the 

 deposit, for the kaolinisation passes gradually from the centre 

 outwards into solid undecomposed granite, a few feet distant. 



A somewhat similar occurrence is known as Hong Hay's Pipe. 

 This was examined by Mr. C. Saint Smith and myself, and the 

 following are our observations. 



Though no work was being carried on at the time of our visit, 

 we were able to descend for about 50 feet, and make a careful 

 examination of the walls of the pipe. Though the central core, 

 which was exceptionally rich in tin, had been removed, we were 

 able to obtain samples of cassiterite from a number of places on 

 the walls of the pipe. The pipe is oval in shape, being about 3 

 feet 6 inches in the long, and 2 feet 6 inches in the short 

 diameter. It occurs in a hard fine-grained modification of the 

 Acid Granite, which ia here strongly jointed in two directions. 

 The master-joints bear N.49^W., and the subsidiary ones N.55°E. 

 None of these joints were altered by impregnations at a distance 

 of three yards from the pipe. The pipe dips at 49° in the first 12 

 feet, in a direction S.35°W.. and then at 35° for the next 40 feet 

 of descent. It then takes a very steep dip in the same direction. 

 The central part of the pipe is reported to have been highly 

 felspathic, soft and easily mined. The present walls of the pipe 

 consist of a white, fine-grained, friable casing of a felspathic nature, 

 containing in places a good deal of cassiterite. At the end of 

 the shallow dip there appeared, in the roof of the pipe, two oval 

 holes which extended upwards for about three feet. One of 

 these was about nine inches, and the other six inches in the longer 

 diameter. Each possessed a smooth surface lined with the same 

 friable felspathic casing aforementioned. About two feet to the 

 west of these, a small vein of quartz, showing comb-structure, 

 entered the pipe. There also occur, at intervals, in other parts 

 of the pipe, veins of iron-stained material containing cassiterite, 

 identical in character with those seen in the Butchart Lode. 



About 50 yards distant, to the south-west, another pipe occurs. 

 This was sunk on for a few feet, but no cassiterite was found. 

 The pipe-material excavated has been left lying at the mouth of 



