<i>Cassier's Magazine</i> of July 1892 had an article on page 207-212, written by H. Hutchins, Lieutenant USN and titled <i>Electrical Equipment of Modern Warships</i> (Part II). It was accompanied by a number of illustrations, including this on page 211, showing the inside of a conning tower. The article does not explain the numbered tubes and levers, settling instead for a somewhat sanguine description of the conduct of battle from the tower.
Unknown illustrator of the time
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