This barograph by Short and Mason of London was likely manufactured just after WW2, circa 1947. It has the hallmarks of a quality instrument, bevelled glass all round to the lift-off lid, a two-compartment chart drawer and a further fixed hardwood panel below, The mechanism is sensitive to minor pressure changes and the reliable clock is by Smiths English Clocks of London. I would imagine that immediately post-war, with shortages the makers obtained this movement - a tried and tested product and major supplier  of clocks and associated products to the Ministry of Defence. Serial number 8/15845 is engraved to the lacquered baseplate along with 'Short and Mason, London'.
Very good condition for its eighty years.
A selection of weekly charts, including some rare original charts by Short and Mason, will be included together with a fresh bottle of recording ink, red or blue, and a re-printed copy of a pamphlet by Negretti and Zambra (who later took over Short and Mason) describing operating instructions and the interpretation of various chart recordings. 
370mm wide x 215mm deep x 228mm high