This plotter is a old find of a wreck sunk in 1914 (build pre 1900) and sold for salvage in the 1950/60. I think its called a Dumaresq. There is some info at dreadnot project, but it's a different model / Mark. Does someone have "handbook of fire control instruments 1914" maybe there is info about this instrument in it. It's 32cm across.
