The form, magnitude, and position of a planet's orbit are determined by the following elements:
1. The semi-axis major, or mean distance, denoted by the symbol a.
2. The eccentricity, e.
3. The longitude of the perihelion, π.
4. The longitude of the ascending node, ☊.
5. The inclination, or the angle contained between the plane of the orbit and that of the ecliptic, i.
And in order to compute a planet's place in its orbit for any given time we must also know
6. Its period, P, and
7. Its mean longitude, l, at a given epoch.
These elements, except the last, are given for all the asteroids, so far as known, in Table II. In column first the number denoting the order of discovery is attached to each name.