But Mr. Irvine had already, in 1874, pointed out, in a brief but valuable communication, that a distinctive peculiarity of Gundulf's work—the absence of plinth to his buttresses—is found "in the castle wall at Rochester (also his)."[990] Thus, it will be seen, the character of the work independently confirms my own conclusion. Some confusion, it may be well to add, has been caused by such forms as "castellum Hrofi" and "castrum quod nominatur Hrofesceaster." In these early forms (as in some other cases), "castrum" denotes the whole of Rochester, girt by its Roman wall, and not (as Mr. Hartshorne assumed throughout) the castle enclosure. Mr. Clark leaves the point in doubt.[991] Before leaving Rochester, I would point out that, unlike the rest of Gundulf's work, this _castrum_ can be closely dated. The conjunction of Lanfranc and William Rufus, in the story of its building, limits it to September, 1087-March, 1089, while Odo's rebellion would probably postpone its construction till his surrender. It is most unfortunate, therefore, that Mr. Clark should write, "This transaction between the bishop and the king occurred about 1076,"[992] when neither Gundulf was bishop nor William king. * * * * * To the case of Newcastle and its keep, I invite special attention, because we have here the tacit admission of Mr. Clark himself that he has antedated, incredible though it may seem, by more than ninety years the erection of this famous keep. To prove this, it is only necessary to print his own conclusions side by side:— (1080.) "Of this masonry there is but little which can be referred to the reign of the Conqueror or William Rufus,—that is, to the eleventh century. Of that period are certainly (_sic_) ... the keeps of Chester, ... and Newcastle, though this last looks later than its recorded (_sic_) date.... Carlisle ... received from Rufus a castle and a keep, now standing; and Newcastle, similarly provided in 1080, also retains its keep.... The castle of Newcastle ... was built by Robert Curthose in 1080, and is a very perfect example of a rectangular Norman keep. Newcastle, built in 1080, has very many chambers" (_Mediæval Military Architecture_, 1884, i. 40, 49, 94, 128). (1172-74.) "Newcastle is an excellent example of a rectangular Norman keep. "Its condition is perfect, its date known (_sic_), and being late (1172-74) in its style, it is more ornate than is usual in its details, and is furnished with all the peculiarities of a late (_sic_) Norman work. "The present castle is an excellent example of the later (_sic_) form of the rectangular Norman keep.... Newcastle has its fellow in the keep of Dover, known to have been the work of Henry the Second" (_Archæological Journal_, 1884).