Rare Map Given New Life

Cunning, Care and Sheer Luck Save Rare Map
New York Times
By MICHAEL WILSON
Published: January 16, 2011



A replica of the 1770 Ratzer map of New York
(from Heritagecharts.com)

 [Excerpted] It was rolled up among other yellowed maps and prints that came off a delivery truck at the Brooklyn Historical Society’s stately office near the East River. Carolyn Hansen, the society’s map cataloguer, began to gently unfurl the canvas.

“You could hear it rip,” said Ms. Hansen, 29, still cringing at the memory. She stopped pulling. But enough of the map, browned with age and dry and crisp as a stale chip, was open to reveal a name: Ratzer.

“We have a Ratzer map,” said James Rossman, chairman of the society, who happened to be in the building that Monday last May. That statement, despite the reverence in its delivery, meant little to the others in the room, but it would soon reverberate in cartography circles and among map scholars.

The name Ratzer is invoked as something of a Da Vinci of New York cartography, and the map was an early edition of his best-known work: a Bernard Ratzer “Plan of the City of New York” in its 1770 state.

There were widely believed to be only three copies of this exact map in existence. One of them belonged to King George III and remains in the British Library in London, where it is displayed occasionally. The other two — one legible, the other tanned and dark with shellac — are at the New-York Historical Society on the Upper West Side and remain in storage but for two or three times a year, when they are pulled out for students.

Restoring this surprise fourth map, aged beyond its 240 years by its destructive shellac coating, became an immediate priority in Brooklyn. Its transformation from literally untouchable to clearly legible and mounted behind glass, to be unveiled at a private party at the society on Wednesday night, involved science, patience and more than a little bit of kitchen-sink cunning, calling to service, at one delicate point, boiling pots of old books used to distill the color of aged paper.

The map had been cut in long strips to allow it to be rolled up for storage. The strips were so brittle they broke when touched. It took a lot of squinting and bending, breath held in, to discover that it was a Ratzer 1770 — its name perhaps an error, as it was most likely completed in 1769.

The two 1770 maps at the New-York Historical Society were gifts of its founder, John Pintard, on Jan. 4, 1810, according to its catalog. That would make, barring the existence of other copies unknown to map archivists, this fourth map in Brooklyn the first one discovered in 200 years.

“It’s incredibly significant,” Mr. Knutzen said. “It’s a needle in a haystack.”

The provenance of the Brooklyn map is a little murky. On the back of the linen that Ms. Hansen began unrolling last May, the name Pierrepont was clearly legible, from the prominent Brooklyn family. But there was no indication how or when it came to land in the Connecticut warehouse, the society said.

Fearful of causing more damage, the society called Jonathan P. Derow, a paper conservationist in Park Slope, who came right over. “It was in terrible condition,” Mr. Derow, 44, said. “I suggested it not be rerolled. Every time it was handled, more pieces were broken apart, and the damage was increased.”

It was too brittle to move to his office, so he made a makeshift plastic tent in the society’s office and inserted a humidifier. The hard paper softened, and Mr. Derow, a conservationist since 1991, carried it away in a mode unthinkable at the time of the map’s creation: a Zipcar.

He washed the map for four days in an alkaline bath that removed acid and grime, and he cut away the linen backing. He aligned the pieces, using a strong magnifying glass and tweezers, and let the map dry, only to see tiny gaps appear between strips, the result of the paper’s shrinking. He rewet it and started over, but let the pieces overlap slightly. That worked: the map shrank perfectly in place.

White lines were visible where the map had ripped, the brighter inner fabrics of the paper standing out from the stained surface. Mr. Derow visited Argosy Book Store on the Upper East Side and bought a handful of obscure old books — among them, for example, “The Select Dialogues of Lucian, to Which Is Added, a New Literal Translation in Latin, With Notes in English,” from 1804 — that were printed on cloth paper, like the map, and not wood pulp.

He performed on them a technique that should chill the blood of any author, wondering where his books will be in 200 years: he baked them in his kitchen stove and boiled them in water. He painted the resulting brackish stew onto the white lines, matching them to the rest of the map.

He framed the finished product behind plexiglass. The society, which paid a reduced rate of $5,000 for the restoration, plans a public viewing in the future.


I don't know if this link will work correctly - it is a photo from the Brooklyn Historical Museum's Facebook page which shows the map in very bad "before" condition unrolled on a table top and a partial view of the conserved map "after."