Various shots of men working in billowing steam clouds in glaciation experiment. Shot of smaller geyser erupting. Shot of explosive-impregnated cord of balloon going off, TILT UP to balloon. MLS of three men preparing to set off explosion, PAN to LALS of balloon. Shot of second explosion, PAN to geyser in eruption. LS of vapour during eruption, TILT DOWN to balloon. Two vertical LASs of balloon. MSs of men attaching explosive cord to balloon cord. LS of two men on site of experiment. MS of steam billowing upwards, heavily dressed men taking technical readings in foreground. LS of geyser eruption, two trees in foreground, TILT UP to top of column of steam, TILT UP to expanding cloud of steam, TILT DOWN. Shots of halo caused by ice crystals formed by explosion in geyser cloud. Various shots of scientist working at ice neuclei detector.