Available only from Hammacher Schlemmer, this handmade desktop storm glass predicts atmospheric change just like its ship-mounted predecessors that explorers and captains used to help navigate storm-ridden seas. Used to predict weather since 1750, this mysterious forecasting instrument was employed by soon-to-be Admiral FitzRoy of the HMS BEAGLE, when he and passenger Charles Darwin, voyaged to the Galapagos Islands in 1831. Although how it functions remains a mystery, the ability of the storm glass to predict atmospheric change is well documented. The contained liquid—a mixture of distilled water, potassium nitrate, ammonium chloride, ethanol, and camphor—appears cloudy when precipitation is approaching; when crystals are visible in the liquid, humid or foggy weather can be expected; a cloudy glass with small stars indicates thunderstorms; a clear glass predicts calm weather. Handcrafted in the Czech Republic, the borosilicate glass orb is hermetically sealed, housed on a wood pedestal, and secured with brass fittings. 6 1/4" H x 3 1/4" Diam. (1 lb.)