National Geographic : 1953 Jan
Canadian Defence Research Board 104 Ihrig and Thomas 4 Cosmic-ray Balloons Are Inflated with Hydrogen, Then Fastened in Tandem The author (left) fills a bag with gas from a steel cylinder. The tent protects delicate fabric from buffeting by the winds (page 113). -* A train of balloons strains at its moorings before take-off at the Swarthmore, Pennsylvania, head quarters of Bartol Research Foundation. Similar trains were used by the Hudson Bay expedition.