f LETTER lir. 



minutes. His diameter is eighty-nine thousand eight 

 hundred miles. 



The distance of Saturn from the sun is nine hun- 

 dred and seven millions nine hundred and fifty-six 

 thousand one hundred and thirty miles. He com- 

 pletes his periodical revolution round the*, sun in 

 twenty-nine years one hundred and seventy-four days 

 and two hours : and revolves upon his own axis in 

 ten hours and sixteen minutes. The diameter of Sa- 

 turn is seventy-nine thousand six hundred miles. 



The distance of the Georgium Sidus from the sun 

 is one thousand eight hundred and fifteen million* 

 nine hundred and twelve thousand two hundred and 

 sixty miles ; and it makes its periodical revolution 

 in eighty-three years one hundred and fifty day* 

 a-nd eighteen hours. The time employed in revolv- 

 ing upon its axis is as yet, like that of Mercury? un- 

 discovered. The diameter of the Georgium Sidus i& 

 thirty-nine thousand nine hundred miles. 



Besides these seven planets,, two other small plane- 

 tary bodies, which revolve round the sun, have lately 

 been discovered. Of these one was first observed on 

 the first of January, 1801, by M. Piazzi, astronomer- 

 royal at Palermo, in Sicily, xvho called it Ferdinandea 

 in honour of his Sicilian Majesty : it is also called 

 Ceres, or Ceres Ferdinandea ; the other, discovered 

 since by Dr. Olbers, of Hamburgh, has been named 

 Pallas. Both these new planets have their orbits 

 between those of Mars and Jupiter ; Ceres revolves 

 round the sun in four years two hundred and twenty- 

 two days ; and is distant from that luminary above 

 two hundred and fifty millions of miles. The distance 

 of Pallas from the sun is about two hundred and se- 

 venty millions of miles. Both are entirely invisi- 

 ble to the naked eye. The diameter of Ceres is 

 estimated by Dr. Harschel at only one hundred and 

 tsixty, and that of Pallas at one hundred and ten 

 English miles. 



Much more might be said concerning the orbs 

 which composed our system, their motion and their 

 one another ia the different points of 



