Paris and Caen: Ballay et Conchon and Buhour 1857. First Edition. -147 pages. Publisher's original green printed wrappers. Later grey-green tape applied to spine with title lettering in calligraphy. Old penciled price on front cover, otherwise minor wear to the wrapper extremities. Properly withdrawn from the Burndy Library, with Bern Dibner gift label on front flyleaf and Alfred Still bookplate on front pastedown. A genuinely scarce, and nicely illustrated, early treatise on telegraphy. 47 numbered illustrations plus some additional charts in the text. Bonel also authored a followup work many years later (1891) on marine telegraphy. Text in French. Fewer than a dozen copies in Worldcat as of this writing. Good. Wrappers.