The great distance between the orbits of Jupiter and Mars, contrary to the general harmony of the system, induced the celebrated Lambert, and professor Bode of Berlin, to predict the existence of a new planet in that part of the heavens. This anticipation was fulfilled on the 1st of January, 1801, when M. Piazzi, a Sicilian as tronomer, discovered a small planet about 160 miles in diameter, revolving round the sun in that region of the heavens. Though the smallness of Ceres, and the ne bulosity which surrounded it, induced some astronomers to exclude it from among the planetary bodies; yet the discovery was supposed to confirm the opinion respect ing the harmony in the distances of the planets ; and the number of primary planets, within the orbit of the Georgium Sidus, was supposed to be complete.
In the following year, however, on the 28th March, 1802, Dr Olbers of Bremen discovered another small planet, to which he gave the name of Pallas, revolving round the sun nearly at the same distance, and in the same time as Ceres, but remarkable for the eccentricity of its orbit, and its inclination to the ecliptic, which far exceed that of all the other bodies in the system.
This curious discovery was succeeded by that qi ano ther small planet, by Mr Harding of Lilienthal, on the 1st September, 1804. This planet, to which he gave the name of Juno, resembles Pallas in the great eccen tricity and inclination of its orbit, and is placed at nearly the same distance from the sun. The remarkable cir cumstance of three small planetary bodies being found in the same region of the heavens, with their orbits mu tually intersecting one another, induced Dr Olbers to imagine that they originally formed one planet, and that more of them might be discovered in the same quarter. He accordingly examined the two regions of the hea vens in which the nodes of their orbits are placed, and on the 29th March, 1807, he discovered a fourth planet, which he called Vesta, similar to the rest both in its position and magnitude. The writer of this part of the article has endeavoured to connect with these singular phenomena, the meteoric stones which have fallen upon our earth, and which he supposes to he-the lesser por tions of a large planet, of which Ceres, Pallas, Juno, and Vesta, are the greater fragments; and has attempt ed to prove, from the inclination and eccentricity of their orbits, from the position of their nodes, and from the place of their aphelia, that these four planets have all diverged from a common centre, and have therefore been combined in one planetary body.
There is perhaps no individual of the present age to whom practical astronomy owes deeper and more last ing obligations, than to Mr Edward Troughton. The great improvements which he has made upon astronomi cal instruments, and the extreme accuracy with which Ile divides them, have rendered his name celebrated in every part of Europe, and have inspired the practical astronomer with a confidence in his observations which he had hitherto been unaccustomed to feel. There is scarcely an observatory of any consequence, either in this country or on the continent, that does not contain some of Mr Troughton's instruments, and are few series of observations in which they have not been used. The admirable observations of Mr Pond on the declina tions of the principal stars, were made with an azimuth circle of Mr Troughton's construction. The mural cir cle, which Mr Groontbridge of Blackheath uses in his numerous and accurate observations, was made by the same artist. The splendid mural circle of 6 feet 2 in ches radius, which Mr Troughton is at present prepar ing for the Royal Observatory of Greenwich, will cost 700/. and will be one of the most magnificent and accu rate instruments that has ever been erected.
While astronomy is thus flourishing in England, un der the care of Dr Maskelyne, Dr Herschel, the rev. Dr Wollaston, Mr Pond, and Mr Groombridge, we are happy to observe that an ardour for this sublime science is beginning to be displayed in this northern part of the island. The admirable papers of professor Playfair, on the figure of the earth, on the astronomy of the Bramins, and on the solids of greatest attraction ; and his impor tant investigations respecting the structure and attrac tion of ShehalJien, entitle him to a high rank among the astronomers of the present age. The erection of a splen did observatory by the public spirited citizens of Glas gow, furnished with instruments by Mr Troughton, and under the c harge of Dr Ure, promises to revive and ex tend the science in that flourishing and liberal city ; and we look forward with sanguine hopes to the labours of colonel Blisbane of Brisbane, who has fitted up an ob servatery with :Nlr Troughton's instruments, and who has devoted his leisure and his fortune to the prosecution of his favourite science.