The 21 Balloons

Professor William Waterman Sherman, a disillusioned schoolteacher, sails in a giant balloon over the Pacific, lands on the island of Krakatoa, and witnesses a stupendous explosion in which that notorious island blows up.

When Professor Sherman is found adrift in the Atlantic clinging to the debris of twenty balloons, all America rocks with curiosity.

Much of the story is based on complete truth – scientific principles behind nineteenth-century balloon inventions and the history of the amazing civilisation found on Krakatoa.

The rest, agrees the author, is absolute nonsense.