Position and Magnitude of the Rings of Saturn, according to Bessel and Struve, for every fortieth day in the year, at 7 hours in the morning. semiconjugate axis of the rings, positive when their northern surface is visible, negative when their southern. inclination of the Northern semiconjugate axis of the rings to the circle of declination; + when East, when West. angle of elevation of the Earth above the plane of the rings, as seen from Saturn; when North, when South. elevation of the Sun above the plane of the rings, as seen from Saturn; + when North, - when South. -- The Conjunction of Saturn will take place on the 18th of January, and the Opposition on the 26th of July. The Right Ascension of this planet will not during the year differ much from 20h., and its declination will not be less than 18° South, so that it will not rise to a great height even when in the meridian. A Table showing the Illuminated Portion of the Discs of Venus and Mars. The numbers in this table are the versed sines of that portion of the Discs, which, to an observer on the Earth, will appear to be illuminated, the apparent diameter of the planet at the time being considered as unity. To a spectator on the Earth, Venus appears most brilliant when her elongation is about 45°, and she is approaching her inferior conjunction, or receding from it; in which positions she will be this year, on the 16th of June and 28th of August. Mars is most brilliant about the time of his opposition to the Sun, being then also nearest to the Earth, in which position he will not be this year. INCREASE OF SIDEREAL TIME IN MEAN SOLAR HOURS, &c. |