The finest 18th-century chart of Boston Harbor, from “The Atlantic Neptune”

[George Callender, surveyor] [A Chart of the Harbour of Boston, Composed from Different Surveys, but Principally from that Taken in 1769, by Mr George Callender, Late Master of His Majesty’s Ship Romney.] [London]: J[oseph] F[rederick] W[allet] Des Barres, August 5, 1775.
Line and stipple engraving and etching on two sheets joined, 28”h x 41”w plus margins, yellow wash color to border. The occasional faint spot of foxing, with faint toning at centerfold and a small smudge near the center. Faint horizontal creases through center; a few grey, vertical striations at far right along an apparent former fold or crease. Better than very good for this chart.

The finest 18th-century chart of Boston Harbor in a desirable later state, with the addition of the extensive American fortifications erected during the 1775 siege. For its combination of accuracy and visual appeal this chart has never been surpassed.

The chart depicts the environs of Boston, Boston Harbor and much of the coastline between Nahant and Hull. Extensive soundings are given, as are numerous navigational aids and hazards. It also provides a great deal of terrestrial detail not available on any other printed map of the time, including bodies of water, roads, structures, and even field boundaries. Elevations and slopes are shown by means of differential shading. An alphabetical key identifies fourteen locations in Boston proper, including batteries and forts, wharves, and the Charlestown ferry.

Of the greatest interest is the careful depiction of the siege of Boston, which began in April 1775. The locations of British fortifications on the Shawmut Peninsula are identified with the help of a legend at upper right. The American entrenchments on the hills surrounding Boston and at the head of Boston Neck are also depicted, having been added to a later state of the chart to keep up with events (This was almost certainly done in 1775 or early 1776, as the March 1776 American emplacement of cannon on Dorchester Heights is not shown.)

The position of the siege quickly becomes clear: Without command of the Charles River and/or Boston Harbor, the Americans could not possibly hope to effect a landing in the town or take it by storming the ramparts on Boston Neck. Conversely, while their command of the Harbor enabled the British to keep the town supplied, any effort to break out into the countryside would have exposed them to flanking attack and left the town itself terribly exposed.

With the added fortifications, the excision of numerous place names, and printed on “LVG”- watermarked paper, this example corresponds most closely to Stevens 3rd state of the chart.

Following their victory in the French and Indian War, the British were faced with the mammoth task of administering and developing thousands of square miles of newly-acquired territory, most of which had never been adequately mapped.

Enter Samuel Holland, a Dutch-born surveyor and engineer who entered British service during the French and Indian War (1756-63). To address these “difficulties” he proposed “an accurate and just Survey… upon… a general scale and uniform plan” of North America east of the Mississippi. The survey would be based on geodetic controls-that is, with the locations of control points established by rigorous astronomical observation, and the intermediate areas pinpointed by means of triangulation. This followed the most advanced European practice, but would represent its first application in North America, and on a much grander scale than hitherto.

The Lord Commissioners approved Holland’s proposal, and in 1764 he was named Surveyor General of both the Province of Quebec and the Northern District of North America. Holland spent the next six years surveying Prince Edward Island, Cape Breton and other areas in and around the Gulf of St. Lawrence. Then from 1770-1774 he focused on the survey of the New England and New York coasts. Of course, he didn’t work alone, but rather was more on the order of a principal investigator overseeing a number of semi-autonomous teams. For example, the survey of Boston Harbor was conducted by one George Callender.

The finished surveys were sent to England, where in 1774 Joseph F.W. Des Barres assumed responsibility for their publication. Des Barres had previously spent ten years in Nova Scotia as Surveyor General and was now to spend another decade preparing North American charts for the British Navy. These were published both separately beginning in 1775 and beginning in 1777 in the compilation known as The Atlantic Neptune. As compiler and publisher Des Barres was responsible for the extraordinary artistic quality of its charts and views.

Boston Engineering Department, List of Maps of Boston, pp. 70-71. Krieger and Cobb, Mapping Boston, p. 106, plate 19. Sellers & Van Ee, Maps and Charts of North America and the West Indies, #945. Stevens, Catalog of the Henry Newton Stevens Collection of the Atlantic Neptune, pp. 211-216. Streeter, II:706.

For background on Des Barres, Holland and the Atlantic Neptune, see Cumming, British Maps of Colonial America, pp.51-56; Harley et al., Mapping the American Revolutionary War, pp.25-8; and Machemer, “Headquartered at Piscataqua: Samuel Holland’s Coastal and Inland Surveys, 1770-1774,” Historical New Hampshire vol. 57 nos. 1 &2, pp.4-25.