The present ceiling in the Great Hall is believed to be its third,
probably installed in the 1860’s in response to the need to relieve
load from the summer beams that were originally located at the third
points in the room. The original eighteenth century faming of the
ceiling appears to have been a three bay system with the joists
spanning approximately ten feet to summer beams, whose dimensions were
approximately 11 inch square. While the design of the original
ceiling cannot be determined from any surviving physical evidence, it
is clear that the Georgian ceiling was at least 1 inch
lower than the current ceiling.
At some unknown date, but probably
during the early nineteenth century, the original ceiling of the Great
Hall was replaced with a ceiling ornamented in a manner typical of the
Federal period, with delicate and attenuated neoclassical motifs.
This ceiling survived at least until circa 1845, when a drawing was
made of it.
This
system appears to have been converted some time
between 1855-1874 to the present system. There is good evidence to
suggest that the revised framing was much too flexible from the
beginning, probably before the plaster ceiling was ever
installed. Attached
to the joists with machine-cut nails, are twenty 3 inch x 3 inch x 10
foot diagonal braces (ten on each side of the room) of circular sawn
Southern Yellow Pine, which span between the top of one joist and the
bottom of the adjacent joist. The shorter diagonal braces (3 inch
x
3 inch x 6 feet) in front of the fireplace bear notches in order to
accommodate bridging boards which were removed in the 1978 campaign. It
is likely that the addition of these twenty diagonal braces
underneath the floor was done in an attempt to strengthen the installed
system, but unfortunately their ability to stiffen the
floor was negligible. The braces appear to have been an
afterthought
and not part of the original design; their insertion required the
removal of several of the bridging boards, which clearly were part of
that original conception. It seems likely that the floor was a
disappointment in terms of its excessive flexibility. This made
immediate alterations necessary in an attempt to stiffen it before the
plaster had even been applied to the ceiling below.
The
Great Hall ceiling plaster is keyed to circular sawn lath attached
directly to the joists with small machine-cut nails. The fact that only
one set of nail holes has been found on the joists indicates that the
present lath and plaster might be the only ceiling to have been applied
to these joists. |
