Antique 19th century Railway signal box block instrument , Eraly 1900s. I believe it was used in the signal box to monitor congestion on the line and originates from the Great Western Railway. It is in good original condition except for some of the original trim/ cornacing has been cut away at some point. The internal workings appear to be complete (but I am not an expert). It has aged well with good colour/patina to the case, brass fittings, bell etc.