From the street to the main entrance a broad driveway wound beneath
the interlacing boughs of a double line of giant oaks, from which
the place had derived its name. Beautiful grounds extended in every
direction, and in the rear of the mansion sloped gently to the edge
of a small lake. Facing the west was the main entrance to the house,
which was nearly surrounded by a broad veranda, commanding a fine
view, not only of the grounds and immediately surrounding country,
but also of the Hudson River, not far distant.

The southwestern portion of the building contained the private rooms
of Hugh Mainwaring, including what was known as the "tower," and had
been added by him soon after he had taken possession of the place.
This part of the house was as far removed as possible from the large
reception-rooms, and the apartments on the second floor comprised
the suite occupied by Mr. Mainwaring. The first of these rooms,
semi-octagonal in form, constituted his private library, and its
elegant furnishings and costly volumes, lining the walls from floor
to ceiling, bespoke the wealth and taste of the owner. Across the
southwestern side of this room heavy portieres partially concealed
the entrance to what Mr. Mainwaring denominated his "sanctum
sanctorum," the room in the tower. This was small, of circular form,
and contained an immense desk, one or two revolving bookcases, and
a large safe, which held his private papers and, it was rumored, the
old Mainwaring jewels. Back of the library was a smoking-room, and
in the rear of that Mr. Mainwaring's dressing-rooms and sleeping
apartments.

This suite of rooms was connected with the remainder of the building
by a long corridor extending from the main hall, but there was on
the south side of the house an entrance and stairway leading directly