A cloud seeding device in which the cloud seeding agent is first vaporized at a high temperature and then condensed as an aerosol as the vapor cools. Flares have been made for producing ice forming or hygroscopic seeding materials. Typical flares burn for 20 seconds to several minutes, and release 10–100 g of seeding material. Airborne flares are usually mounted in external racks on cloud seeding aircraft. Large flares are burned upstream or within clouds; smaller flares may be ignited and dropped through clouds.