have only fhewn what will happen In general, for 
one War 5 having only drawn the Spiral of the Suns 
Motion for that Time : And if a Speffator, on any 
Parallel of Latitude, fhould want to fee the fame 
Appearances of the Sun's Riling and Setting every 
Year, and, confequently, to have the particular Days 
thereof to be £lill of the fame Length with thofe* of 
the Year, he muft travel Weft ward every Year 90 
Decrees on the fame Parallel. 
20. The Inhabitants of Venus will be very careful in 
adding" a Day to fome particular Part of every fourth 
Year, 'to keep ftill the fame Seafons to the fame 
Times 5 becaufe, as the great annual Change of the 
Equinoxes and Solftices will fhiftthe Seafons forward 
a Quarter of a Day every Year, they would, in 36 
Years, fhift the Seal ms forward thro' all the Days of 
the Year: Bur, by this intercala'ry Day, every fourth 
Year will be a Leap-Year 5 which will bring her Time 
to an even Reckoning, and keep her Calendar right. 
21. The great Change of the Sun's Declination 
every Day, which caufes his Altitude, at Noon, or 
any other Hour, and his Amplitude at Riling and 
Setting, to be fo very different in Places lyiug under 
the fame Parallels of Latitude, will, be of one lingu- 
lar Ufe in Venus , the like whereof we fhall never 
enjoy on the Earth; and that is no lefs than the giv- 
ing a fare and eafy Method of finding the Longitude. 
Por, fuppofe to one Place, at Noon, the Sun's De- 
clination is 30 Degrees, and to another Place it is, 
only 20 Degrees 35 Minutes at Noon, in the fame 
rcvolutional Spiral, going from the Equator toward 
the Northern Tropic; the Difference, of thefe two 
Declinations is 9 Degrees 25 Minutes: In the fame 
Spiral 
