At least half of the present Second Quadrangle site came to the College as part of White Hall; but no new buildings appeared there until Thelwall's library, a stone building over a pillared loggia, appeared on the north side c.1627. After demolition, this was rebuilt in the opposite (south-west) corner in 1676-77, initially as a free-standing building, with the junior and senior common rooms underneath. Now known as the Fellows' Library, it contains the original Carolean bookcases, desks and seats, and many of the books, from the 1620s library and its temporary successor. The residential staircases, all three storeys high with a uniform roofscape of small, ogee gables, were built in 1639 (XIII), 1640 (VI), 1678 (VIII), 1691-92 (X), 1699 (XI) and 1713 (XII). On several of these occasions, building followed the acquisition of extra pieces of land. Despite its patchwork history and uneven refacing, this quadrangle seems at first sight to be the result of a single, uniformly executed plan.