L’Astronautique.

The full-length synthesis that gave the new science its name in book form: this 1930 edition reprints REP’s 1928 preface by General Ferrié alongside a new preface by E. Fichot arguing the book proves astronautics a genuine science rather than reverie, and opens with REP’s own Avertissement and epigraphs from Frantz von Hoefft and Hermann Oberth describing astronautics as a problem of momentum, not energy. An errata leaf and a folding nomogram for the mass-ratio/velocity/time relation of Chapter I close the volume, and an appendix reprints the Prix REP-Hirsch rules also found with this collection’s copies of the 1928 book.

Both exemplars here are largely unopened: their folded signatures were never slit along the top and fore edges with a paper-knife, as French books of this era were commonly issued, leaving much of the text block unreadable without cutting it open — a condition collectors prize as evidence a copy went unread when new.

See also L’Exploration Par Fusées De La Très Haute Atmosphère (1928), where Esnault-Pelterie first put “Astronautique” into print, and its 1935 supplement, L’Astronautique (Complément). The Russian edition (1950) is also available in this collection.