﻿394 ilE. G. BAREOW OX THE [^^g- IQOS, 



margins of the latter uumerous patches of gravel have heen left 

 unworked, but whether these are sufficiently rich to pay with more 

 modern methods is the problem that awaits solution. 



In the deeper channels there was more gravel, and so tlie refuse- 

 heaps were higher, and often stand out above the level of the peat 

 at the present day ; they are often too small to be distinguished 

 from a distance, but they are identified by the fact that bushes will 

 and do grow on them' but will not grow on the peat. Thus 

 the presence or the position of the older channel can still often 

 be traced by these heaps and the bushes growing on them. In many 

 cases the heaps were only as high as the peat, and no trace of 

 them can be seen even close at hand ; but the bushes will still grow 

 on these, and mark the position of a thicker gravel-deposit in a 

 moss at the present time. 



AVe may now return to the consideration of Kenton Marsh, and 

 see what information can be gleaned from that ground. Before the 

 re-starting of the works the marsh was covered by a fairly-smooth 

 sheet of peat, and at first its surface suggests that it has not been 

 disturbed. But an expert soon detects the sagging at the sides due 

 to the washing-away of part of the deposits during streaming ; the 

 hollow is masked, not actually hidden, by the recent peat-growth. 

 In the centre of the marsh is a solitary bush with a green moss- 

 patch in front ; the bush is growing on a tip of gravel, and the 

 green patch marks a hole choked with a growth of soft moss, a 

 death-trap to any one getting into it. Towards the southern end 

 of the marsh is a short line of bushes, showing that the deeper 

 channel was followed here : but the first bush suggests a solitary 

 trial in waterlogged ground. The general opinion, founded on the 

 presence of these bushes, was that the whole marsh had been worked 

 for tin, but it has proved wrong. 



The Eecent Workings at Kenton Marsh. 



On opening up the edge of the marsh, a mass of peat-fragments, 

 rough gravel, and soft dirt, the refuse left by the previous workers, 

 was met with ; evidently, the ground here had been turned over 

 before. It was at once seen that resort had been had to the old 

 habit of throwing, or dumping, behind the face the refuse of the 

 washings, for the bed of the stream, flowing from the marsh, has 

 been blocked almost to the level of the floor or sh^lf of granite, 

 an obvious impediment to start with. Then the whole of the mass 

 described had to be washed instead of the basal part only, involv- 

 ing the treatment of a large amount of barren material. Further, 

 the granite-floor or shelf seems to be more or less kaolinized, 

 and becomes ' quick ' if much trampled on. This floor, however, is 

 uneven, and the inequality has resulted in the preservation of a 

 number of small pockets of tin and wolfram. Despite all draw- 

 backs, the results were so encouraging that the marsh was tested 

 to see how much of it had been streamed. A trench through the 



