Jeff, I bought that map at an auction in London. Here's a bit of its history:
The Turgot map was published in 1739 as an atlas of 20 non-overlapping sectional bird's-eye view maps (at a scale of approximately 1/400) in isometric perspective toward the southeast. When put together, those 20 sections combine to make one 100 x 126 inches map.
In 1734 Michel-Étienne Turgot, chief of the municipality of Paris as provost of merchants, decided to promote the reputation of Paris for Parisian, provincial or foreign elites by implementing a new map of the city. He asked Louis Bretez, member of the Royal Academy of Painting and Sculpture and professor of perspective, to draw up the plan of Paris and its suburbs. Turgot requested a very faithful reproduction with great accuracy, so Bretez was allowed to enter into the mansions, houses and gardens in order to take measurements and draw pictures. He worked on the map for two years, from 1734 until 1736.
In 1736, Claude Lucas, engraver of the Royal Academy of Sciences, created the 20 sheets of the plan. The plan was published in 1739, and the prints were bound in volumes offered to the King, the members of the Academy, and the Municipality. Additional copies were to serve as representations of France to foreigners.
