Now we have two or three views in the Island of Skye. They are in black and white, but your minds must clothe them in the rich tints we saw just now. Note the treeless character of the scene. And see here a mountain rising nakedly to the sky, without even the covering of grass or heather. And again, in this same Island of Skye is Loch Coruisk, one of the wildest and remotest spots in the United Kingdom. From the head of the loch there is a walk of several miles over a mountain pass before you reach the first habitation of man. So curious is the contrast between the ocean edge of the British Islands and the thickly populated plain of England. London is the largest city in the world, but the Highlands of Scotland are among the least populated regions of all Europe. Here, therefore, is the playground of many of the British people, who go in the summer time to walk over these mountains, to steam through these lochs, to catch the fish, and to shoot the deer and the birds. So they gain the health which enables them to work in London at the business of the Empire during the dark winter. [Sidenote: 50. Clett Rock, Thurso.] [Sidenote: 51. Duncansby Head.] Finally we come out to the ocean itself, and here we see the great history of Nature. Layer upon layer, hundreds of layers thick, we have the beds of rock which were once laid down at the bottom of the sea. They are now dry and hard, and have been cut into by the waves, so that this stack of rock, which was once a piece of Scotland, is now detached as a little island. Here is yet another scene where the rocks are of a different kind, and the shape of the islets therefore different. [Sidenote: 52. Atlantic Rollers.] [Sidenote: 53. Sunset on the Atlantic.] These are the rollers of the rough northern sea, which work upon the hard stone. But occasionally even the Atlantic Ocean calms. As we look out to the west on this lovely summer evening, let us remember a fact never to be forgotten. The islands of Britain, which centre in London, with all their natural beauty and their 43 millions of people, are what they are, the focus of a great Empire, partly because they are set as islands in the ocean, and partly because they were peopled long ago by proud and masterful sea races of men. LECTURE IV. HISTORIC CENTRES AND THEIR INFLUENCE UPON NATIONAL LIFE. [Sidenote: 1. Stonehenge.]