Theory of the motion of the moon which exhibits all its irregularities
In addition to the foreword (which was not written by Euler), this book contains an introduction, 18 chapters, and "Additamentum continens alias methodos investigandi motus lunae inaequalitates" as mentioned in the title. The foreword indicates that this work was not an essay for a competition, which did not win the prize (see the letter from Jacobi to P. H. Fuss from March/April 1848; Bibl. math. Vol. 83, 1907/8, p. 302). Rather, it was inspired by the winning essay of Clairaut, about which Euler sent a report to the Academy.
Original Source Citation
St. Petersburg: Imperial Academy of Sciences, pp. 1-347.
Opera Omnia Citation
Series 2, Volume 23, pp.64-336.