Publication of The Atlantic Neptune between 1777 and 1781 was a bolt-out-of-the-blue event in the history of map-making in North America and the British Empire. This four-volume atlas contained sea charts and artistic views of the east coast of North America, from the St. Lawrence River to the southern tip of Florida.

Largely the work of Swiss-born military engineer Joseph Frederick Wallet Des Barres, with crucial contributions from fellow surveyor Samuel Holland, the atlas was the first from the New World to be based on scientific surveys tied to the Greenwich meridian.

As academic and author Stephen J. Hornsby points out in is recently published book, Surveyors of Empire, maps were never the same after The Atlantic Neptune appeared.

“With the problem of establishing longitude resolved,” he writes, “the shape of eastern North America represented on Des Barres’s charts looked strikingly different to that depicted on earlier maps; his charts marked the beginning of the modern mapping of the continent.”

Des Barres and Holland came to know the eastern coast of North America intimately but in different ways, based on their preferred surveying methods. Holland was most comfortable surveying from land, focusing on coastlines, rivers, settlements and terrain. Des Barres was a marine surveyor, conducting hydrographic soundings off the coastlines. These different approaches would be reflected in the charts published in The Atlantic Neptune.

“The two approaches represented different ways of knowing land and sea and would become increasingly familiar as British surveyors fanned out across the globe in the late eighteenth and early nineteenth centuries,” Hornsby writes.

Their surveying techniques may have differed, but both Des Barres and Holland exploited their surveys to advance personal interests. They identified good tracts of land that they later claimed, accumulating significant land holdings. Of the two, Holland was the better financial manager. In fact, Des Barres became so hard up for cash, according to Hornsby, that “engraving the survey charts and publishing them in a nautical atlas offered [him] a financial life-line.”