“The elements of the new Planet have been pretty well determined by several European astronomers. The following I have extracted from the Almanack[232] for 1787. Mean Longitude 4^h 2° 21′ 58″ } To Dec. 31, Mean Anomaly 4 8 53 56 } 1787, at noon, Place of Aphel. 11 23 28 2 } Paris. Ascending Node 2 12 52 54 } Mean Motion in Long. in 365 days 4° 19′ 47″ in 30 days 21′ 21″ in 24 hours 42″.7 “The Aphelion and Nodes move according to the precession of the Equinoxes; that is 50″.3 per ann. Inclination of the Orbit 46′ 13″ Log. of greatest distance from the Sun 6.3007701 Log. of least distance 6.2594052 The Log. of the Earth’s mean dist. from ☉ being 5.0000000 “Dr. Halley’s Table of the equation of ♃’s orbit will do very well for computing the place of Herschel’s planet, only subtracting 1/16 part of the equation there found; the greatest equation of this planet being 5° 27′ 16″. So, if from the Log. to any degree of anomaly, in the Table for Jupiter, we subtract 1/76 part of the excess of that Log. above the least, and to the remainder add the constant Logarithm .5647750, we shall have the Log. for ♅ sufficiently accurate. On these principles, I have computed the Right Ascension of ♅, and find both agree with my own observation, to a few seconds. “I am sorry you have engaged the notice of *******. Men of his principles, with a printing-press at command, are the greatest pests of society. “My very bad state of health, and a multiplicity of business, have prevented my answering yours as soon as I wished to have done it. I am, Dear Sir, your Friend and Humble Servant, “DAVID RITTENHOUSE. “ANDREW ELLICOTT, ESQ. Baltimore.” ----- Footnote 232: The Nautical Almanack. ----- The correctness of the calculations respecting the Georgium Sidus, stated in this letter, is noticed in the following extract from one of Mr. Ellicott’s Almanacks. “The reader will find in this Almanack a continuation of the planet ♅. The elements on which the calculations were made, appear by observation to be very accurately determined, not only by the astronomers in Europe, but by my ingenious friend Mr. Rittenhouse, whose knowledge of the theory and practice of astronomy, is not surpassed in the old world.”