Hi Dodes
I think the ship in the picture could be HMS Grudge or a similar custom built gunboat. I think they were based upon the Flat iron or Ant class gunboats from the 1880s. They were longer and wider than the Ant class because they were gun trial vessels, one of which was fitted with a 9.2inch gun and possibly bigger calibre weapons. Grudge survived to become a tender vessel and if my memory is correct was not scrapped until the 1950s. If you want any more info I suggest the 'Send For a Gunboat' book by Antony Preston which was re-published a few years ago, it contains all the gunboats, gunvessels, gunsloops and other minor vessels which carried big guns from the mid 1800s to 1900. A very good read.
Hope this helps.
Nick B