It was during the Franco-Prussian War (1870–1871) in which Verne was conscripted as a coastguard; he was having financial difficulties (his previous works were not paid royalties); his father had died recently; and he had witnessed a public execution, which had disturbed him.
Era în timpul războiului franco-prusac (1870-1871), perioadă în care Verne a fost înrolat în Paza de Coastă, avea dificultăți financiare (nu îi fuseseră plătite drepturile de autor pentru lucrări anterioare), tatăl său murise de curând și asistase la o execuție publică, care îl impresionase.