Paris, Librairie Militaire J. Dumaine, 1866.
Octavo, vi, 75 pages plus a folding leaf of diagrams, a large folding plan, and an original albumen paper photograph (186 × 125 mm) on a tipped-in card mount, captioned in manuscript 'Planchette Photographique | A Chevallier'.
Original pale orange printed wrappers; covers and edges very slightly dusty; foot of the spine lightly bumped; scattered light foxing; first blank neatly excised, leaving a stub (but possibly as issued); a near-fine copy, uncut and entirely unopened.
Auguste Chevallier's ingenious photographic plane-table produced a disc-shaped horizontal panorama by means of a rotating lens. Comparing images taken at different vantage points allowed the surveyor accurately to calculate distances and heights as with a regular plane table, but with less room for human error in taking observations. This publication comprises a testimonial for this invention (apparently an improved version of one of his earlier inventions). This copy is inscribed and signed on the half-title 'A Monsieur le Duc de Luynes, humble hommage de l'inventeur, A. Chevallier'. The caption on the mount of the original photograph appears to us to be in the same hand.