These three examples are all that are known on the mainland of Scotland south of the Caledonian valley. A few years ago they were mere grass-covered hillocks, indistinguishable from many others that are yet to be seen in various quarters of the same wide district of country. It is impossible to say how many of these unexamined mounds, which exist abundantly in the valleys of the Forth and Teith for instance, may be of similar character. But it is possible to say that where three have been found without being specially looked for, the probability is that more will be found when they are looked for. The present position of our knowledge is that there are three examples south of the Caledonian valley, but if I were to conclude that these three are all that exist in that wide region I should be drawing from my ignorance of the actual facts a conclusion which could only be drawn from complete knowledge obtained by exhaustive investigation. The case is far otherwise with reference to the district of country that lies to the north of the Caledonian valley and the isles around the northern and western coasts. In such remote and frequently rugged and barren localities the remorseless activity of the agricultural improver has made but little progress in the removal of the ancient landmarks, and Brochs, and sepulchral cairns, stone circles and standing monoliths are still comparatively abundant, though every season diminishes their number. Some years ago I attempted an enumeration of the remains in the northern counties of Scotland that were either certainly known to be Brochs or were inferred to possess that character, judging from external appearances. The list has been published[72] for seven years, and the corrections made upon it during that time have not appreciably affected its total results. These are roughly stated as follows:—in Shetland, there are 75 Brochs; in Orkney, 70; in Caithness, 79; in Sutherland, 60; in Ross-shire, 38; and in Inverness-shire, 47; giving a gross total for the five northern counties of Scotland of 370. Admitting that there must be some instances included in the enumeration which subsequent examination may prove to be remains of a different character, it is equally probable that others will be found which have not been included in the list, and the errors in these opposite directions may be expected nearly to balance each other. But if we suppose that it will be necessary to deduct so large a proportion as 20 per cent, we should still have a gross total of 300 Brochs in the five northern counties. The full significance of such a result is scarcely realised at once. It means that we have here the remains of a period of architectural activity which has no parallel in the early history of our country. ----- Footnote 72: _Archæologia Scotica_, vol. v. pp. 178-197. -----