The telegraph : translated from the French
A late nineteenth-century English translation of a French technical treatise on telegraphy, published in London and New York by Routledge in 1895 and written by Alcide Ludovic Ternant for students and practical electricians. Its pictures are plain black-and-white line engravings of apparatus on flat bases, with lettered parts and numbered figures, showing instruments such as magnets, coils, a recording lever on a drum, and a geared transmitter. A designer might borrow their clean mechanical linework and labelled diagram style for retro technical graphics.
