While utilizing a very similar configuration to the Daedalus class of the Royal Navy, the French Pluton class was a smaller and much more experimental design. They took advantage of the location of the main battery atop the gravity generator to better bring to bear developments in incendiary weapons along Martian lines. While never wholly successful, the terror they created made them legendary.
Here we see an early example, possibly the Eurale. She is fitted with the unusual 'lazy susan' style turret which allowed the upper works and main battery to be separately rotated. These were quickly superseded as overly complicated and not a good fit for more conventional weapon systems when incendiaries fell out of fashion.
This is another illustration for 'Spacecraft of the First World War.'