Note 230 — MEMOIR OF THE LIFE OF DAVID RITTENHOUSE; CONTINUED, FROM THE TIME OF HIS SETTLEMENT IN PHILADELPHIA.

Among those who have observed, since Dr. Herschel’s discovery of the Georgium Sidus, new phænomena in the heavens, may be ranked the following:

M. Piazzi, a Sicilian astronomer, who, on the 1st of January, 1801, discovered a small planet revolving round the sun, between the orbits of Jupiter and Mars, named Ceres: Dr. Olbers, of Bremen, who, on the 28th of March in the following year, discovered another small planet, to which he gave the name of Pallas, which revolves round the sun nearly at the same distance, and in the same time, as Ceres; and afterwards, viz. on the 29th of March, another planet, which he called Vesta; similar to the others, both in its position and magnitude: and

Mr. Harding, of Lilienthal, who, between these two last mentioned periods, viz. on the 1st of September, 1804, discovered a fourth planet (but the third in the order of time,) also small, to which he gave the name of Juno; resembling Pallas in a great excentricity of its orbit, and the inclination of this to the ecliptic, and placed at nearly the same distance from the sun.

The Georgium Sidus was not discovered until about fifteen years before Dr. Rittenhouse’s death; and the first discovered of the four last mentioned planets was not known in America, for almost five years after that event.