The library at Peterhouse was lengthened in 1633. It is 75 ft. long by 25 ft. broad, and each of its side-walls is pierced by a range of three-light windows. The cases (fig. 111) were put up between 1641 and 1648. Like those at S. John's, they stand at right angles to the walls between the windows, but they are detached, and not continuous with the panelwork. Originally they were just eight feet high, but have since been heightened to accommodate more books. Each case is still divided by a central pilaster. So far they do not present any striking peculiarity, but I wish to draw attention to a curious contrivance, which we shall find subsequently reproduced in various forms, though not exactly as it is seen here; for these cases were evidently admired, and imitated in several other colleges. The chains had been taken off the books at Peterhouse in 1593-94, when they were first moved into the new library; so that desks attached to the cases were not required. Nor were lower cases, with desks at the top of them, provided. But the convenience of the reader was considered, up to a certain point, by the provision of a seat, 12 in. wide and 23 in. high, extending along the side of each case, and returned along the wall between it and the case next to it. This arrangement may still be seen in the two compartments at the west end of the room, one on each side of the door of entrance. The ends of the seat or 'podium,' are concealed by boldly carved wings[451]. [Illustration: Fig. 111. Bookcases in the Library of Peterhouse, Cambridge.] The convenience of this type of case was evidently recognised at once, for we find it copied, more or less exactly, in the south room of the University Library (1649); at Jesus College (1663); at Gonville and Caius College (1675); at Emmanuel College (1677); and at Pembroke College (1690). [Illustration: Fig. 112. Bookcases in the south room of the University Library, Cambridge.] The south room of the University Library, on the first floor, is 25 ft. wide and was originally 67 ft. long. It was lighted by eight windows in the north wall, and by nine windows in the south wall, each of two lights. There was also a window of four lights in the east gable, as we learn from Loggan's print, and probably a window in the west gable also[452]. It was entered by a door, in the north-east corner, approached by a "vice," or turret-stair. This door was fortunately left intact when the east building was erected in 1755. The room has been but little altered, and still preserves the beautiful roof, the contract for which is dated 25 June, 1466[453].