It was common for paintings/etchings to be made based on existing paintings in the 19th century - I'm guessing the painting link I gave was probably close to an

It was common for paintings/etchings to be made based on existing paintings in the 19th century - I'm guessing the painting link I gave was probably close to an original or source. There's lots of similar images on the internet, this image on Alamy claims to scanned from a Victorian mechanical‑engineering book of the 1880s https://www.alamy.com/an-old-engraving-showing-the-british-floating-dry-dock-bermuda-under-tow-two-ironclads-doing-the-towing-in-the-atlantic-ocean-in-1869-it-is-from-a-victorian-book-of-the-1880s-iron-hull-maintenance-required-a-dry-docks-around-the-world-mobile-floating-versions-were-used-bermuda-was-constructed-at-the-campbell-and-johnstone-thames-shipyard-it-was-launched-in-1868-manoeuvring-was-assisted-by-the-paddle-sloop-hms-terrible-shown-left-it-arrived-in-bermuda-in-july-1869-the-dry-dock-was-replaced-by-a-new-steel-dock-in-1906-her-remains-are-still-visible-off-spanish-point-bermuda-image382747418.html?imageid=E6A4111D-5495-4CE3-8312-67EC97C72A75&pn=1&searchId=ebc1309c204d4dce4baf08c317c7aeaa&searchtype=9 https://www.alamy.com/an-old-engraving-showing-the-british-f...