These are the round towers, called “burghs,” “brochs,” or “Picts’ castles.” We noticed these in Sutherland and Caithness. They are cylinders of masonry tapering upward into a truncated cone, or are waisted, like a dice-box. The walls, composed of an outer and an inner concentric shell of untrimmed stone, have been evenly set, but without mortar. The rude masonry is bound together by four or five courses of slabs of slate, placed crosswise, so as to leave, in the thickness of the walls, a gallery of inclined plane winding up to the top, like a cork-screw. They are lighted by small openings or slits in the inside. The rest of the wall is filled in with loose stones, and it may measure in thickness from ten to fifteen feet. The towers vary in height, from twenty-five to forty feet, and in diameter, from thirty to fifty. The little doors, on the ground level, are low and narrow; sometimes not over three feet high. There are over four hundred examples of these towers in the north and northwest of Scotland, and in the isles, but are all more or less ruined. In the Shetlands are seventy-five; in the Orkneys, seventy; in Caithness, seventy-nine; in Sutherland, sixty; on Long Island, thirty-eight; in Skye, thirty, etc. Not less remarkable are these stony memorials of the past than are the peculiarities of the religion, social life, dress, and literary aspects of the Highlanders and North Scottish people--composed as they are of Norse and Celtic strains. These have blended to produce a race of people that differs perceptibly from the southern Scotch Lowlanders. Moreover, in the north and west there was not, as in the south, such a long-continued struggle of many and varied elements, local, continental, religious, artistic, moral, and economic, nor, until a century or two ago, such a blending of many ethnic stocks, but only of two or three. This comparative isolation on the one hand, and exposure to, and penetration by, the manifold forces of culture on the other, have left their differing results visible in both history, human characteristics, and deposits of thought. Civilization is of the south and the Lowlands; but Scottish music and poetry, in their nascent, original, most forceful forms, are of the north and west. This is true, also, because among the most potent causes of difference are the aspects of nature, so strikingly in contrast as one nears England or Norway. Scottish song and verse were born among the mountains nearer the North Star, and the first bards were hunters and cragsmen. In the early poetry and music of no land, more than in that of Scotland, are primitive art and pre-ancient nature more in accord. “Amid all the changes of human feeling and action, we seem to hear the solemn surge of the Atlantic breakers, or the moan of the wind across the desolate moors, or the sigh of the pine woods, or the dash of the waterfalls and the roar of the floods as the rain-clouds burst among the glens.”