We left behind us the islands of Lunga, Luing, and Seil, and entered the narrow Sound of Kerrera, with its border of Old Red conglomerate resting on the clay-slate of the district. We had passed Esdaile near enough to see the workmen employed in the quarries of the island, so extensively known in commerce for their roofing slate, and several small vessels beside them, engaged in loading; and now we had got a step higher in the geological scale, and could mark from the deck the peculiar character of the conglomerate, which, in cliffs washed by the sea, when the binding matrix is softer than the pebbles which it encloses, roughens, instead of being polished, by the action of the waves, and which, along the eastern side of the Sound here, seems as if formed of cannon-shot, of all sizes, embedded in cement. The Sound terminates in the beautiful bay of Oban, so quiet and sheltered, with its two island breakwaters in front,--its semi-circular sweep of hill behind,--its long white-walled village, bent like a bow, to conform to the inflection of the shore,--its mural precipices behind, tapestried with ivy,--its rich patches of green pasture,--its bosky dingles of shrub and tree,--and, perched on the seaward promontory, its old, time-eaten keep. "In one part of the harbor of Oban," says Dr. James Anderson, in his "Practical Treatise on Peat Moss," (1794), "where the depth of the sea is about twenty fathoms, the bottom is found to consist of quick peat, which affords no safe anchorage." I made inquiry at the captain of the steamer, regarding this submerged deposit, but he had never heard of it. There are, however, many such on the coasts of both Britain and Ireland. We staid at Oban for several hours, waiting the arrival of the Fort William steamer; and, taking out hammer and chisel from my bag, I stepped ashore to question my ancient acquaintance, the Old Red conglomerate, and was fortunate enough to meet on the pier-head, as I landed, one of the best of companions for assisting in such work, Mr. Colin Elder, of Isle Ornsay,--the gentleman who had so kindly furnished my friend Mr. Swanson with an asylum for his family, when there was no longer a home for them in Small Isles. "You are much in luck," he said, after our first greeting: "one of the villagers, in improving his garden, has just made a cut for some fifteen or twenty yards along the face of the precipice behind the village, and laid open the line of junction between the conglomerate and the clay-slate. Let us go and see it."