Theoria motuum planetarum et cometarum continens methodum facilem exaliquot observationibus orbitas cum planetarum tum cometarum determinandi. Una cum calculo, quo cometae, qui annis 1680 et 1681 itemque ejus, qui nuper est visus, motus verus investigatur

Rare first edition of Euler's first work devoted to astronomy (cf. Houzeau and Lancaster I, 11948. Poggendorff I, 689. La Lande 422. DSB IV, 467-484.)

Illustrated with a frontispiece (printed on f. A4) and 4 engraved plates at the end of the volume.

Some minor foxing, mostly towards the end of the volume.

Modern half vellum binding, smooth unlettered spine, comb-marbled paper boards, red edges.

This work dates from the very beginning of Euler's stay in Berlin (where he had been invited by Frederick II of Prussia), a period of intense activity across several fields of science.

The work is described as a "fundamental work on calculation of orbits" in the Dictionary of Scientific Biography.

Jérôme De La Lande already noted in his Bibliographie astronomique (Paris, 1803): «Ce livre est le premier où l'on ait traité analytiquement les orbites des planètes et des comètes».

One of the principal works of dynamical astronomy, Euler’s equations being of capital importance.