On the top of the hill above the Clapper Rocks, on the east coast of St. Mary’s, is a barrow which was opened by Mr. Bonsor in 1903, and in his opinion it is the finest specimen in the West of England. Altogether in Scilly there must be nearly a hundred examples, and no doubt many have been destroyed. The built graves lined with stones are thought to be of earlier date than those formed of only one large block. Very often there is a double circle of stones round the mound, an inner and an outer, the covering slabs being in some cases eight or nine feet long. [Illustration: ST. MARTIN’S PIER] On the summit of nearly every hill these desolate green barrows are to be seen, reminding us of that far mightier barrow, the “great and shapely mound” to Achilles, “raised on the high headland, so that it might be seen from afar by future generations of men.” For long the islands have been identified with the Cassiterides, or tin-producing islands, mentioned by ancient writers. But there does not seem to be sufficient evidence to prove this indisputably, and experts are not satisfied that tin was ever worked in Scilly. Not only so, but they go farther, and prophesy that it never will be--in fact, to parody the Spanish proverb, that it would require a gold-mine to work a tin-mine in the islands! There has been much heated controversy on this subject of late; but then, there were warm discussions concerning the tin trade as far back as the second century B.C., so what can be expected nowadays? When there are many different opinions, put forward by as many different writers, all learned and all firmly convinced that the “other fellow’s a fool,” what course is left for the unlearned multitude, after hearing all that has to be said, but to retain an “open mind” on the subject? To prove my open-mindedness, I will not omit to quote the story about the Cassiterides which has usually been taken to refer to the Islands of Scilly. Strabo, who lived at the end of B.C. and the beginning of A.D., tells us that the inhabitants of the Cassiterides obtained from their mines tin and lead, which they used to barter for earthen vessels, salt, and instruments of brass; that the Phoenicians found commerce with them so lucrative that they kept it a secret from all the world, but the Romans sent vessels to follow a trader on his voyage. To deceive them, he ran his ship ashore elsewhere, and the whole crew nearly perished. For this public-spirited act he was rewarded from the common treasury, besides receiving the value of his lost ship and cargo. But, according to Strabo, the Romans found out the trade at last. Publius Crassus (whoever he may have been) sailed across to the islands, ascertained that tin was near the surface, and indicated the route for the benefit of traders, “although the passage was longer than that to Britain.”