278 Mifcellanea Curiofa. 



feconds, 32 thirds ; and her apparent Diame- 

 ter 3 1 minutes, 30 ieconds. But in her Qua- 

 dratures at a mean Diftance from the Earth, 

 I make the Horizontal Parallax of the Moon 

 to be 5? 9 minutes, 40 feconds, her Horary Mo- 

 tion 32 minutes, 12 feconds, 2 thirds, and her 

 apparent Diameter, 3 1 minutes, 3 feconds. The 

 Moon in an Octant to the Sun, and at a mean 

 diftance, hath ,her Centre diftant from the Cen- 

 tre of the Earth about 60 £ of the Earth s Semi- 

 diameters. 



The Sun's Horizontal Parallax I make to be 

 1 o Ieconds, and its apparent Diameter at a mean 

 diftance from the Earth, I make 32 minutes, 

 15 (econds. 



The Atmofphere of the Earth, by difper- 

 fing and refracting the Sun's Light, cafts a 

 Shadow, as if it were an Opake Body, at leaft 

 to the height of 40 or $0 Geographical Miles 

 (by a Geographical Mile, I mean the fixcieth 

 part of a Degree of a great Circle, on the 

 Earth's Surface.) This Shadow falling upon 

 the Moon in a Lunar Ecliple, makes the 

 Earth's Shadow be the larger or broader. And 

 to each Mile of the Earth's Atmofphere, is cor* 

 refpondent a Second in the Moon* Disk, fo 

 that the Semi-diameter of the Earth's ftiadow 

 projected upon the Disk of the Moon, is to be 

 increafed about £0 feconds • Or, which is all 

 one, in a Lunar Eclipfe, the Horizontal Paral- 

 lax of the Moon is to be increafed in the Ratio 

 of about 70 to 69. 



Thus far the Theory of this Incomparable 

 Mathematician. And if we had many Places 

 of the Moon accurately obferv'd, efpecially 

 about her Quadratures, and thefe well com- 



par'd 



