Ed Yost own interests turned toward reviving the lost practice of manned hot-air ballooning. This technology had first been invented in France by in the late 18th century by pioneers led by the Montgolfier brothers, but under the Montgolfier system, the balloon's air was heated by a ground fire prior to the balloon being released. The inherent danger of this type of balloon flight led to the system being abandoned when hydrogen and later helium became available. One of Yost's key engineering insights was that a hot-air balloon could be made to carry its own fuel. The invention of relatively light burners
Air Balloon (song) she had lost agency to her label, Parlophone. In 2018, Allen described "Air Balloon" as her least favourite song, and agreed with a fan who suggested that it "stunk of label pressure as a lead single". "Air Balloon" is described by "Billboard" as "more of a loopy lullaby than a slice of social commentary", with a nonchalant Allen singing, "Come meet me in the sky, I'll be waiting for you/And we can't hear what they say/Up in my air balloon, air balloon, air balloon." The song gets its toy piano arrangement, creaseless beat and offbeat Kurt Cobain shout-out partially from