The Dome and the Lightning Rod
The
lightning rod
which tops the dome is a story in itself. It is a
"Franklin" rod, constructed and grounded to Benjamin
Franklin's specifications. In some respects, the useof
this type of lightning rod was also a political
statement, expressing support for Franklin's theories on
protection of public buildings from lightning strikes
and the rejection of the opposing theories supported by
King George III. The pointed lightning rod atop such an
important new public building was a powerful symbol of
the independence and ingenuity of the young nation.
As an architect trained in London and with a brother who
had a bookshop in Annapolis, Clark would have been
familiar with the writings of Benjamin Franklin. In
addition, Charles Willson Peale confirmed Clark's
design. On July 14, 1788, he and his brother went to
Philadelphia to see His Excellency Doctor Franklin to
ask his opinion on the efficacy of lightning rods on the
State House. They were unable to see Franklin, but did
see Robert Patterson and David Rittenhouse, both eminent
authorities on the physical sciences. Peale reported
that Mr. Rittenhouse was of the opinion that "if the
points are good and near anough the Building and the
part going into the ground so deep as to get into soft
earth no danger is to be apprehended, but if the end
could be put in water of a Well it would be best."
The engineering of the lightning rod and the acorn which
holds it in place represents an astonishing achievement.
Protruding 28' into the air, the rod is anchored at its
bottom to the top of the dome. It then runs through the
pedestal and the acorn and is surmounted by a copper
weather vane. The acorn and pedestal have served to
stabilize the Franklin rod and hold it in place for more
than two centuries of extremes of Maryland weather.
The dome which Clark designed and built for the State
House has been the defining landmark of the Annapolis
skyline for more than 225 years. It was also, for many
years, a popular spot from which to observe the city and
the Chesapeake Bay beyond. Charles Willson Peale planned
a dramatic cyclorama of Annapolis with eight views from
the dome and a centerpiece drawing of State Circle from
Cornhill Street. Only the drawing of the State House was
completed and published in 1789. Thomas Jefferson spent
a most enjoyable three hours in September 1790 on the
balcony of the dome with James Madison, Thomas Lee
Shippen and an Annapolis friend who entertained them
with the gossip related to each of the houses they could
see from their perch above the town.
In 1996, an examination of the dome and the acorn
revealed that almost all of the material in the acorn,
its pedestal and the lightning rod was original from the
18th century. During the summer and fall of 1996, the
acorn was removed and replaced by a new one. The new
acorn is constructed of 31 pieces of cypress made by
craftspeople from around the state and is clad in copper
and gilded on the top, like the original. The original
lightning rod has remained intact and continues to serve
as it has for more than 225 years, although a steel
sleeve has been placed around it inside the new acorn to
strengthen it.