Two versions of a hitherto unrecorded War of 1812-era map proposing a novel plan for fortifying New York Harbor against invasion.

Though the United States had won legendary naval victories early in the War of 1812, the hard fact was that it remained badly outgunned by the much larger Royal Navy. Fearing assault on its harbors, or even outright invasion, the country constructed and refurbished fortifications up and down the East Coast. Though New York City was never attacked, the British did conduct operations in the Chesapeake region, capturing and burning Washington, D.C. in August 1814, and later made a similar though unsuccessful attempt against New Orleans.

The engraved plans offered here illustrate a wildly impractical proposal for fortifying the Narrows between Brooklyn and Staten Island, which form a natural choke point at the entrance to New York Harbor. The plans, clearly impressions from different states of the same plate, depict New York Harbor and Bay from Sandy Hook to lower Manhattan, with the surrounding areas shown in outline. Shoals, shallows and rocks are indicated by stippling and small “x’s,” and 13 locations are labeled with capital letters, clearly corresponding to an legend or explanatory text (This text is not present and was possibly never produced.) The plans depict a series of barriers at the Narrows, creating a narrow channel with extremely tight 180-degree turns, thereby forcing passing vessels to slow down to be rowed or towed through. This would expose a hostile force to the concentrated fire of shore batteries flanking the Narrows on both shorelines. Above the main plan is a “Section of the Out Fall and the dam Tide water.” Its intent is hard to discern, but it may depict a cross-section of the proposed dam and barriers, which appear to have the shape of a prism.

As mentioned above, the pair of plans are impressions pulled from two states of the same plate. The changes are not merely cosmetic, as they appear to illustrate two phases of the author’s thinking about his design. The first plan shows the entrance to the winding barrier blocked by a large dam (labeled “K”), with only a narrow passage (“P”) on the Staten Island side. It includes numerous manuscript additions and changes in ink, among them the insertion of the word “PRISAM” [sic] into the title as well as the following note:

“This PRISAM DEFENCE when applied within the Bar, Defends the Habour City Town Shipping & & by preventing the in roads of a Navel force thereby rendering such Harbours Impregnable NEW YORK HARBOUR is Naturaly adapted to the PRISAM Defence”

The second plan bears none of the proposed text changes, but the installation at the Narrows has been much changed, with the dam removed, the barriers brought even closer together, and the works on the flanking shorelines revised.

The maps were recently removed from a scrapbook originally kept by Henry Membery Western (1797-1853), son of mapmaker Thomas Western (1755-1820). Born in England, Thomas arrived in New York City in 1794, where we worked as a piano manufacturer and dealer in musical instruments. He suffered at least two disasters, including the deaths of his wife and daughters in 1803, possibly of yellow fever, and the loss of his house in a major 1812 fire. In 1814 he was listed as an “insolvent debtor,” and by 1816 he had moved on to Alexandria and then on to Cuba, where he tried to set up as a sugar exporter. He died in Matanzas of yellow fever in 1820. (Ancestry.com)

I find no mention of Western’s “prisam defence” in the New York press of the period, and the nature of his interest in the subject is simply unknown. Perhaps it was an attempt to right his financial affairs. At any rate the scheme was utterly harebrained: the breadth of the Narrows and depth of its waters far outstripped both the technical expertise of the period and the financial resources at the disposal of the American government.

As mentioned above, the plans seem to be utterly unrecorded. In all, a curious and hitherto unknown piece of New York City history from the War of 1812 era.

References

Not in Augustyn & Cohen, Manhattan in Maps; Haskell, Manhattan Maps: A Cooperative List; or OCLC.