French cruiser Amiral Aube was a Gloire-class armored cruiser built for the French Navy in the early 1900s. She served in the English Channel and the Mediterranean during World War I. In early 1918, the ship was sent to Murmansk to support Allied forces during the when they intervened in the Russian Civil War.

qsy-complains-a-lot:

Canon de 27cm Mle 1870

Used in battleships and coast defenses c.1870~1918.
274mm caliber 216kg shells, 434m/s muzzle velocity giving it an estimated 300mm of penetration in wrought iron armor at combat range, breech-loading single shot.

Picture taken c.1885 by Gustave Bourgain onboard a Colbert-class French ironclad, below the center battery.

Note the boarding weapons on racks on the left side of the picture, including cutlasses and Lefaucheux Mle1858 revolvers. The Colbert-class ironclads were also armed with, beside a variety of other naval guns, more than a dozen Hotchkiss 37mm revolving cannons, four 356mm torpedo tubes and a ram.