Eight-panel single doors were employed extensively throughout the eighteenth century, and this is one of the most picturesque and distinctive of Philadelphia types. For the most part the panels were arranged as shown by the doors of the Perot-Morris, Powel and Wharton houses with a pair of small and large panels in alternation. Other notable instances are to be seen at Loudoun, Chalkley Hall and the Blackwell house. The top or first and third pairs were about half as high as their width, while the second and fourth pairs were oblong and usually of the same size, their height about one and one-half times their width. The door at Upsala is a rare instance of the fourth pair of panels lower than the second, whereas that at Number 301 South Seventh Street shows this type with molded flat panels. As is well shown by the door of the Perot-Morris house, the fourth rail was the broad lock rail, and as in those days the latch was often separate, it was frequently placed on the rail above, and hence often referred to as the latch rail. Another less common type of eight-panel single door is shown in accompanying illustrations by doors at Number 4908 Germantown Avenue, Number 39 Fisher's Lane, Wayne Junction and Number 224 South Eighth Street. The panel arrangement consisted of three pairs of nearly square panels above the lock rail and one pair twice as high below. Of the doors mentioned, that at Wayne Junction is unique in its flat molded panels. A corresponding panel arrangement of double doors is to be seen at The Highlands. Usually, however, four-panel double doors took the alternate small and large panel arrangement and were virtually halves of the more common type of eight-panel single door. Such doors at Stenton, Cliveden and the Morris house are illustrated in detail, and similar ones gave entrance to Hope Lodge, Woodford and Vernon. The Woodford doors are interesting for their glazed quatrefoil openings in the top pair of panels, the Vernon doors for a handsome brass knocker on the second panel of each one. For the most part Philadelphia doorways were deeply recessed in connection with stone construction because of the great thickness of the walls. Paneled jambs were let into the reveals of the opening, and whatever the panel arrangement of the door, a corresponding arrangement was followed in paneling the jambs and the soffit of the arch or flat lintel above. Such a distinctive and pleasing feature did this become that it was widely adapted to brick construction, the outward projection of pilasters and engaged columns, often both, supporting pediments and entablatures which had the effect of increasing the depth of brick walls.