HMS Mercury (1878)

HMS Mercury was an Iris-class second class cruiser of the Royal Navy. The two ships of the class were the first all steel ships in the Royal Navy. She was distinguished from the Iris by her straight bow, which gave her a slightly shorter length of 315 feet. The ship carried a complement of 275 officers and men.

Mercury was laid down at Pembroke Dockyard on 16 March 1876, launched on 17 April 1878 and completed on 18 September 1879. Originally equipped with a light barque rig, her sails were soon removed and the class became the first "mastless cruisers". She had an "unprecedented amount of space taken up with machinery", but was thought of so highly that she was rearmed three times during her service.

Mercury served with the Portsmouth Reserve from 1879 to 1890, in China from 1890 to 1895 and with the Portsmouth Reserve again from 1895 to 1903. She served as a navigation school ship for navigating officers from 1903 to 1905 and a submarine depot ship at Portsmouth from 1906 to 1913, and at Harwich in 1913. There were plans to rename her Columbine in 1912, but these were rescinded and instead she was hulked at Rosyth in 1914 with the port depot ship there, HMS Columbine, the former HMS Wild Swan (1876). She was moved to Chatham, where she became an accommodation ship from 7 January 1918, and was paid off in March 1919. She was eventually sold for scrap to the Forth Shipbreaking Company, at Bo'ness, on 9 July 1919.