[A] The inordinate delay in the appearance of that supplementary volume has, indeed, been chiefly owing to the necessity under which the writer felt himself, of obtaining as many memoranda as possible of mediæval buildings in Italy and Normandy, now in process of destruction, before that destruction should be consummated by the Restorer or Revolutionist. His whole time has been lately occupied in taking drawings from one side of buildings, of which masons were knocking down the other; nor can he yet pledge himself to any time for the publication of the conclusion of "Modern Painters;" he can only promise that its delay shall not be owing to any indolence on his part. Every apology is, however, due to the reader, for the hasty and imperfect execution of the plates. Having much more serious work in hand, and desiring merely to render them illustrative of my meaning, I have sometimes very completely failed even of that humble aim; and the text, being generally written before the illustration was completed, sometimes naïvely describes as sublime or beautiful, features which the plate represents by a blot. I shall be grateful if the reader will in such cases refer the expressions of praise to the Architecture, and not to the illustration. So far, however, as their coarseness and rudeness admit, the plates are valuable; being either copies of memoranda made upon the spot, or (Plates IX. and XI.) enlarged and adapted from Daguerreotypes, taken under my own superintendence. Unfortunately, the great distance from the ground of the window which is the subject of Plate IX. renders even the Daguerreotype indistinct; and I cannot answer for the accuracy of any of the mosaic details, more especially of those which surround the window, and which I rather imagine, in the original, to be sculptured in relief. The general proportions are, however, studiously preserved; the spirals of the shafts are counted, and the effect of the whole is as near that of the thing itself, as is necessary for the purposes of illustration for which the plate is given. For the accuracy of the rest I can answer, even to the cracks in the stones, and the number of them; and though the looseness of the drawing, and the picturesque character which is necessarily given by an endeavor to draw old buildings as they actually appear, may perhaps diminish their credit for architectural veracity, they will do so unjustly.