Everything Nauticalproudly presents thisChrome Stormglass and Plaque Set. The amazing stormglass comes mounted on a solid wood plaque with an engraved brass legend. The sealed glass tube holding a unique combination of chemicals is housed in a secure polished brass cylinder. Mount it with the included accessories or allow it to free stand anywhere outside of direct sunlight for optimal results. Stormglass instruments were first used in the 1750s as a storm warning instrument. Changing weather affects the solubility of the mixture of chemicals within the sealed glass tube. Depending on the type of formations, you can predict coming weather up to 48-hours in advance. This mysterious reaction is believed by some to be caused by electromagnetic changes created by weather and sun storms. This product makes a unique and exciting gift for any weather-watcher in your life. Add a touch of excitement and mystery with class to any room and let the wonder begin