New, mighty acorn State House dome: Old wooden structure supported lightning rod for 208 years.

August 07, 1996

WHY DID an 18th century architect opt for an 800-pound wooden structure in the shape of an acorn at the top of the Maryland State House dome? Now that it has deteriorated badly over 208 years, why replace the acorn?

There are good answers to both questions. That acorn may look decorative but it is an integral part of the dome that soars high over Annapolis. It provides the stability for the State House lightning rod. Not just an ordinary lightning rod, either, but the world's largest working Franklin rod -- following inventor-statesman Benjamin Franklin's precise design.

For 208 years, the mighty acorn helped protect the State House from lightning and fires. But time has inevitably taken its toll. The 5-foot-8-inch cypress acorn is shot through with dry rot. This has made the 28-foot wrought-iron Franklin rod it stabilizes wobbly. It could topple under sustained winds of 80 mph.

High winds have damaged earlier structures on the hill. The first State House lost much of its roof to a hurricane in 1775; lightning and fire then did further damage to the roof and cupola. A month after the domed roof was completed, "George Washington's hurricane" of July 1788 hit Mount Vernon with gale-force winds, then moved up the Chesapeake Bay and blasted Annapolis. The dome survived intact.

Once installed this fall, the new acorn will again secure the dome's lightning rod. It will be made in 31 horizontal slices of cypress wood, each slipped over the rod, then joined together. The original gold color of the cap will be restored along with a base of copper sheeting. Total cost: just $84,000, thanks to donations of material and craftsmanship. A worthy project.

To Colonial citizens, the acorn stood for sturdiness, stability and longevity. It served as a capstone to a mighty civic project in Annapolis that was meant to last. Maryland's State House stood as a metaphor for our young nation. Its dome has, indeed, been a stabilizing force. May the new acorn serve the building as admirably for the next 200 years.

Pub Date: 8/07/96

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