It is not easy to say when bay windows were first introduced, but apparently not earlier than the middle of the fourteenth century; they were, however, generally adopted during the fifteenth, and the Perpendicular style affords many beautiful examples. Among them may be mentioned South Wingfield (Fig. 36), and Fawsley in Northamptonshire (Fig. 68). The ceilings of these bays were not infrequently vaulted in stone, with elaborate tracery and cusps, as is the case in this fine window at Fawsley, the Deanery at Wells, the oriel at Great Chalfield in Wiltshire, and many others. The great bay at Fawsley is of unusual interest, inasmuch as there is a small chamber above it, which was originally approached by a narrow newel staircase. Owing to its remote position, tradition has assigned this chamber as the secret place where the celebrated Martin Marprelate tracts were printed. Bay windows were occasionally introduced on an upper floor, being corbelled out from the face of the wall; such windows are called oriels. There is a good example at Sherborne in Dorset, of Perpendicular date (Fig. 69). The earliest known example of an oriel window is at Prudhoe Castle, in Northumberland; it is not actually corbelled out, however, but rests on a crosswall below. [Illustration: 70. Glastonbury, Somerset. Front of Wood House, showing Window and Doors.] The construction of wooden houses, formed of stout uprights placed at short intervals, lent itself freely to the introduction of long ranges of window lights such as those in a street front at Glastonbury (Fig. 70), where the framing of the walls served also as the frame of the window. * * * * *