These round towers have given rise to much controversy as to their date and use, but the whole of our knowledge regarding them has been admirably summed up by Dr. J. Anderson, in his _Scotland in Early Christian Times_, p. 52. It is there shown that these round towers are outliers of a group of which Ireland is the home. As has been pointed out in the Introduction to the first volume, the period of the Irish round towers is comprised between the end of the ninth century and the beginning of the twelfth century. We have above seen that the first church in Brechin was founded by a colony of ecclesiastics, after the Irish model, about the beginning of the eleventh century, and the probability is that the tower was erected during that century. Brechin is said to have been destroyed by the Danes in 1012, and it seems not unlikely that the monks there would follow the plan adopted in Ireland in the case of similar invasions, in order to protect their valuables--viz., to erect a strong detached round tower as a place of refuge and security. The Brechin tower corresponds in all its features with Irish examples. The detached situation; the circular form tapering from the projecting base to the summit; the doorway raised 6 feet 6 inches above the ground, and ornamented with details and sculptures similar to those of Irish models; the division into stories by means of internal string courses to sustain wooden floors, but without any means of access except ladders, and lighted by two small windows with inclined jambs; the four large windows at the top facing the cardinal points; the ornament of the cornice and the pointed roof (although this, no doubt, is a later restoration), are all elements distinctive of the old Irish round towers. The stones of which the tower is built are large, and they are cut to the circle, but are not laid in regular courses. The tower measures 86 feet 9 inches to the base of the sloping roof. It is divided into seven unequal stories, with string courses in the interior. The Irish round towers are divided by Miss Stoke’s classification into four periods; and the nature of the masonry of the Brechin Tower corresponds with the third of those periods, which in Ireland would be the first half of the tenth century, but in this derivative example would, doubtless, be somewhat later. The doorway, with its sculpture (Fig. 612), is especially interesting. It presents features all characteristic of its Irish originals. The aperture is small, and the jambs are inclined inwards towards the top. They are in single stones the full breadth of the wall, and are covered with a [Illustration: FIG. 612.--Brechin Cathedral. Doorway of Round Tower.]