Plate CXVIII (118) from the second edition monograph on the steam engine and steam navigation by Thomas Tredgold and W. S. B. Woolhouse. The first edition, published in 1838, consisted of two volumes and titled, 'The Steam Engine: Its Invention and Progressive Improvement, an Investigation of its Principles, and its Application to Navigation, Manufactures, and Railways.' The second volume consisted of only plates. In the later edition, published 1845, only volume 2 was published under the title: ;Illustrations of Steam Machinery and Steam Naval Architecture.' The uncolored print depicts the port-side view of the US mail steamboat 'Neptune.' She flies various identifying flags on her masts that include a flag with the sea god Neptune with his trident on a seahorse-drawn chariot.
