Geikie in his geological map of Scotland gives it a corner all to itself and describes it from the bottom up. Above the groundwork on which the Scuir rests ran the river, and driftwood and shingle may still be found to mark its course to this day. Just as in Skye we saw the lavas overflew and fill the hollows, so here the river bed was in due time filled up by ‘the pitchstone-porphyry that is now the Scuir’. Then the valleys were removed, and the high lands, and in its appointed season—came the sea.

Not that all geologists agree on the point. Hugh Miller believed that ‘the gigantic Scuir of Eigg rests on the remains of a prostrate forest’ and is there by upheaval. But Geikie’s river shows the vaster and, as it happens, the truer sweep.

However, those, like myself, who know little of geology, may be interested not so much in the likelihoods of the discussion as in the surprising fact that it exists; just as it might not greatly matter to us what exactly was the nature of the rock which troubled Hugh Miller at Ru-Stoir, to the east of the island of Eigg, as that it belonged to ‘the age of the Plesiosaurus and the fossil crocodile’. ‘I hammered lustily,’ he wrote, ‘and laid open in the dark red shale a vertebral joint, a rib, and a parallelogramical fragment of solid bone . . . I had thus already found in connection with it [Ru-Stoir] well-nigh as many reptilian remains as had been found in all Scotland before.’ Banks of basking crocodiles and plesiosauri, here where the ancient river ran! And there could be little doubt of it.

And even in the quite recent story of man, Eigg provides a cross-section lurid enough to satisfy the most morbid curiosity. Our host, by way of illustration, led us to Uamh Fhraing (the Cave of Frances), now generally known as the Cave of the Massacre.

The tale of the massacre is widely known, for Sir Walter Scott has it in his Tales of a Grandfather, and other writers have debated its origins at length. That it is no legend is certain, for less than a century ago Hugh Miller describes the human bones as he found them still on the floor of the cave. ‘The floor, for about a hundred yards inwards from the narrow vestibule, resembles that of a charnel-house. At almost every step we come upon heaps of human bones grouped together. The skulls, with the exception of a few fragments, have disappeared; for travellers in the Hebrides have of late years been numerous and curious; and many a museum—that at Abbotsford among the rest—exhibits, in a grinning skull, its memorial of the Massacre of Eigg.’