ECLIPSES OF THE SATELLITES OF JUPITER IN 1858,

Mean Time, Washington Observatory (Astronomical account).

A Table showing the Illuminated Portions 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 diameters of the planets at the time being considered as unity.

To a spectator on the Earth, Venus appears most brilliant when between her greatest elongation and her inferior conjunction; in which position she will be in October, November, and part of December.

Mars is most brilliant about the time of his opposition to the Sun, being then also nearest the Earth. The opposition will take place on the 15th of May.

Elements for Determining the Geocentric Position, Magnitude, and Appear

p denotes the inclination of the northern semi-minor axes of the rings to the circle of declination; + East, West.

a the apparent outer major axis of the outer ring.

outer minor axis of the outer ring; + North surface visible, South surface visible.

I the elevation of the Earth above the plane of the ring, as seen from Saturn; North, - South.

l' the elevation of the Sun above the plane of the ring, as seen from Saturn; +North, — South.