A Dutch weather glass or 'donderglas' Anonymous

A Dutch weather glass or 'donderglas' Anonymous, probably mid to late 19th century The half pear-shaped blown glass reservoir with applied vertical bands of crimped ribs to sides and to the front of tapered serpentine spout rising from the waist, The top and bottom with knopped terminals the upper to enable tying of a line for wall hanging, 25cm (10ins) high. Provenance: Private collection, Hampshire. The design of the current lot was devised by Johann Wolfgang von Goethe in around 1793 but had to wait until after his death to be recognised as useful for predicting impending stormy weather. Often called a Liege barometer the instrument worked by filling the reservoir approximately two-thirds full and hanging on the wall, with a sudden drop of air pressure (which precedes a storm) the level in the spout would rise - possibly spilling over thus provides a simple but effective early warning for stormy weather. The applied vertical bands of crimped decoration to the spout and body of the current lot probably serve as basic reference for the relative amount of fluid lost after a significant rapid drop in barometric pressure.