44 ASTRONOMICAL and ^' 



The next to Venus is our Earth, half covered with a "black 

 cap, which is always in oppofition to the Sun. She makes. 

 365^ diurnal rotations on her axis in the fame time flie per- 

 forms her annual revolution : her axis declines from that of 



the ecliptic, 23 degrees 29 minutes, prefer vin^ its parallelifm 

 round the Sun ; her north pole tends towards, the firfl degree 

 of Cancer. The Moon, accompanying the Earth, performs her 

 periodical revolution in 27 days, 7 hours, 43 minutes, turn- 

 ing on her axis exacftly once in the fame time, and performing 

 her fynodical revolution, or from fun to fun, in 29 days, 12 

 hours, 45 minutes. On the circle reprefenting her orbit are 

 marked the nodes and degrees of her north and foudi lati- 

 tudes, the plane of which forrn& an angle of 5 degrees with 

 the plane of the ecliptic; the nodes have their back motions, 

 pafhng through all the figns and degrees in 1 8f years. There 



ri 



is another body, half covered with a black cap, which at all 

 times fhews its daik part ; it turns on its axis, which declines 



r 



from the axis of the ecliptic and keeps parallel to itfelf round 



the earth ; it exhibits all the phenomena explained by the . 

 above moon. 



. Mars is without the earth's orbit, with his axis perpendicu- 

 lar to the ecliptic, performing his annual motion in 686 U 

 days, and diurnal in 24 hours, 40 minutes, . 



• Jupiter is at a greater diftance from the Sim than Mars^ 

 with his axis perpendicular to the ecHptic, completing his, 

 annual circuit in 11 years, and 314 days, 18 hours, andhiai 



diurnal motion in c) hours, 56 miiiut€S% 



Satur% 



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