In contrast to Cyprian Southack's highly inaccurate chart of Casco Bay, this chart by Des Barres is a model of accuracy. Des Barres was widely known for his achievements as a hydrographer, the accuracy of his charts, and his artistic presentation. Des Barres is best known for his monumental undertaking in surveying the coast of North America and the Atlantic Neptune, a compilation of these surveys. Des Barres combined meticulous surveying with new equipment such as the chronometer (to determine longitude) and the theodolite (used to make precise measurements of vertical and horizontal angles).
Joseph Frederick Wallet Des Barres was born in Switzerland in 1721. He received mathematical training at the University of Basel. As a young man he moved to England, became a British subject, and trained as a military engineer. In 1756 he joined the Royal American Regiment as a lieutenant. During this time he most likely met two fellow officers in his regiment (Samuel Holland and Captain James Cook, both military engineers like Des Barres) who would play an important role in compiling Des Barres' famous atlas, the Atlantic Neptune. He spent 1763 to 1774 surveying the North American eastern coast with great accuracy with a team typically composed of 5 to 23 men. In 1774 he returned to England and spent the next ten years preparing charts from his survey information. It is uncertain how many charts he completed in total for the Atlantic Neptune. Des Barres lists 257 but others have since been found that were not originally listed. There are many variants of the Atlantic Neptune no two atlases are exactly the same because different charts were compiled for specific purposes or tours of duty.
Des Barres not only charted the coast with great attention to detail, but he also took into account the topography of the land. Though Des Barres preferred coastal surveying to land surveying, he included much information about the land, marking hills, towns, fields, and other landforms that would be visible from the coast on his charts. His team took many soundings, setting a new standard for accuracy. Many charts prior to Des Barres were highly inaccurate and unreliable. But Des Barres not only created a meticulously accurate chart, but a chart that was artistically pleasing as well.
L'Esprit des Journaux, in Paris, in its contemporary review of the Atlantic Neptune, said that it was "one of the most remarkable products of human industry that has ever been given to the world through the arts of printing and engraving." Indeed, it was a "most splendid collection of charts, plans, and views ever published." Even after 200 years, Des Barres' charts are still accurate and valued. The copper plates still exist, and reprints are periodically made and sold to the day.