This is a mid-Edwardian era barograph in polished mahogany, retailed, and signed,  by the well respected Army & Navy Stores, London.  The mechanism is similar in design to the Short & Mason design and their 1904 patent which refers to the ‘use of aneroid underneath slab and easier to adjust’. However, this particular example clearly has the aneroid diaphragm situated level with the brass base with a raised brass cap over - perhaps made by a competitor anxious to avoid an infringement of the patent? The instrument is certainly quite rare and in excellent working order. It's all original, including the glass ink bottle and brass stopper. 
The barograph uses standard recording charts – a selection will be included together with a fresh bottle of recording ink and a re-printed copy of an instruction manual by Negretti & Zambra which illustrates the interpretation of various chart recordings.
317mm wide x 190mm high x 175mm deep.