A correction of the theory of the motion of the satelite of Saturn, by that ingenious astronomer Mr. Edmund Hally.

Abstract Sir, I here send you an <italic>Astronomical account</italic> of the most remote of all the <italic>Planets</italic> of our <italic>Vortex</italic>, and withal of the most inconsiderable, I mean of the <italic>Satellite</italic> of Saturn, discovered in the year 1655 by <italic>Monsieur Christian Hugens</italic> of <italic>Zulichem</italic>, who in that accurate Treatise of his <italic>Systema Saturnium</italic>, from <italic>pag</italic>. 25 to 34 gives us the <italic>Theory</italic> of its <italic>Motion</italic> as well as the shortness of the interval of time between his <italic>Observations</italic> would admit; and since him I know none that have gone about to improve the said <italic>Theory</italic>.