g . FIGURE OF THE PLANET SATURN, 



Obfervations onandon the poles than at the latitude of about 45 degrees, 

 whkh'its°fin<'u- '^^^ equatorial diameter is however confiderably greater than 

 Ur figure is af- tiie polar. 



curtained. jp, order to have the teftimony of all my inftruments, on the 



fubjedt of the ftrudure of the planet Saturn, I had prepared 

 the 40-feet refledior for obferving it in the meridian. I ufed a 

 magnifying power of 360, and faw its form exactly as I had 

 feen it in the 10 and 20-feet inftruments. The planet is flat- 

 tened at the poles, but the fpheroid that would arife from this 

 flattening is modified by fome other caufe, which I fuppofe to 

 be the attraftion of the ring. It refembles a parallelogram, 

 . one fide whereof is the equatorial, the other the polar dia- 

 meter, with the four corners rounded off fo as to leave both 

 the equatorial and polar regions flatter than they would be in 

 the regular fpheroidical figure. 



The planet Jupiter being by this time got up to a confi- 

 derable altitude, I viewed it alternately with Saturn in the 10- 

 feet refle6ior, with a power of 500. The outlines of the figure 

 .■ of Saturn are as defcribed in the obfervation of the 40-feet 



' . telefcope ; but ihofe of Jupiter are fuch as to give a greater 



curvature both to the polar and equatorial rt-gions than takes 

 place at the poles or equator of Saturn which are compara. 

 lively much flatter. 



May 12. I viewed Saturn and Jupiter alternately with 

 my large 10-feet telefcope of 24 inches aperture; and faw 

 plainly that the former planet differs much in figure from the 

 latter. 



The temperature of the air is fo changeable that no large 

 mirror can a6t well. 



May 13. lO-feet refledor, power 300. The Ibadow of the 

 ring upon the body, and of the body upon the ring, are very 

 black, and not of the dufky colour of the heavens about the 

 planet, or of the fpace betwen the ring and planet, and be- 

 tween the two rings. The north-following part of the ring 

 clofe to the planet, is as it were cut ofl^ by the fliadow of the 

 body ; and the ihadow of the ring lies fouth of it, but clofe to 

 the projedion of the ring. 



The planet is of the form defcribed in the obfervation of 

 the 40-feet telefcope; I fee it fo diftinftly that there can 

 be no doubt of it. By the appearance, I fliould think the 



points 



