Complete in three volumes. This is probably the second edition (see below). Attractive Art Deco illustrations to the green boards. Each volume has on its front paste-down a multi-layer coloured card diagram-cum-model, as well as a tinted fronstipiece. All volumes are illustrated with diagrams and monochrome photographs, and occasional tinted photographs. No date, but “In the first edition of this work but little was about the carbon incandescent electric lamp.”, but now “There are several makes of metallic filament lamps in the market”. This shift from carbon filament to metallic filament lamps took place in the early years of the twentieth century. The first edition (which I also have for sale) is dated 1902, so a date of perhaps 1910-1920 seems plausible for this edition. Condition: Covers bright and clean, with just a little rubbing of the surface to Volume III, which also has a little soiling to the cover. Soiling to external page edges. Diagrams and models in good order, binding firm- overall a very nice set. Please ask if you would like more information, or photographs.