Manchester Memoirs, Vol. Ixv. (192 1), No. 13 7 



first discovered. The working of tin for the manufacture of 

 bronze would attract men perhaps even more than gold. At 

 any rate it is legitimate to conclude that the men who washed 

 the gold of Dartmoor were also extracting the tin and taking 

 it back to the Eastern Mediterranean in order to make bronze. 



An apparent exception is of particular value for testing a 

 theory. We are fortunate enough to possess one in the case 

 of St. Austell Moor. This is the most important tin-washing 

 area of Cornwall. The geological formation is granite. Why 

 therefore were not the megalith builders working the tin that 

 existed there ? Surely if they were so keen for gold and tin 

 they would have hit upon this obvious spot, teeming as it was 

 with the minerals that they so desired ? It may be claimed 

 that megaliths once existed there, but that they have been 

 destroyed. That may be so; but the fact that St. Austell 

 Moor is now the most prolific source of tin in Devonshire and 

 Cornwall suggests rather that the megalith-builders never 

 found it out at all, and that the supplies tapped in modern 

 times were practically virgin. The places where the megalith- 

 builders settled in numbers, Dartmoor for example, are almost 

 bereft of tin, although we know from the presence of tin lodes 

 on the summit of Dartmoor* that stream tin must have existed 

 there in the past in great quantities. 



Mr. J. Wilfrid Jackson, of the Manchester Museum, has 

 supplied the explanation in this case. He points out that 

 the tin-washing area of St. Austell Moor is that of the source 

 of china clay, the product of the disintegration of the granite. 

 And he suggests that the tin would be left alone by the early 

 men on account of the great depth of superficial deposit of 

 china clay that overlaid them. His views are fully confirmed 

 by the map published in the Memoirs of the Geological 

 Survey (11, 105, 106, 108, 170, 174, 177, 178), which shows 

 that the tin-lodes occur in the areas covered with deposits of 

 china clay. It is also said that in this region the tin deposits 

 are very capricious, which would constitute another reason 

 why the area should apparently be overlooked. 



The theory that the megalith-builders of Devon and 

 Cornwall were attracted to the spots where they settled because 

 of the presence primarily of gold, and secondarily perhaps of 

 tin, accounts without difficulty for the facts. How otherwise 

 can it be explained that St. Austell Moor was ignored while 

 the other granite areas were ransacked? It is well known 



* This can readily be seen by a reference to the Geological Survey Map of 

 the district. 



