“Les merveilles de l’industrie, ou description des principales industries modernes”, Louis Figuier (1873-1877). The 4-volume book is in French, but the engravings are indeed wonderful: Part 1 (750 pages), Part 2 (736 pages), Part 3 (687 pages) & Part 4 (744 pages). A sample of the illustrations of part one and four can be found here and here. Below: salt mines in Wieliska, Poland (extra large illustration). Related: Three thousand pages of 19th century technology.