266 Astronomy. {Lecture 17. 



The Anlcecii, or Antoecians, are those inhabitants of 

 the globe, who have the same longitude with us, but are 

 as far to the south of the equator as we are to the north. 

 Their hour is the same as ours, it being noon, &c. with 

 both at the same time. Their days are equal to our 

 nights, and the conirary. And their summer is our winter. 



The Pcricecii, or Perioecians, are those that lie under the 

 same parallel of latitude with us, on the same side of the 

 equator, only are distant one hundred and eighty degrees 

 of longitude, viz. a semicircle. 



They have contrary hours, it being noon with them 

 when it is midnight with us. Their days and nights are 

 of the same length with ours. Their season or time of the 

 year is also the same cs with us. 



The Antipodes are such inhabitants as have the same 

 latitude south as we have north, but diffetr one hundred 

 and eighty degrees in longitude j that is, they and we have 

 opposite parallels and opposite meridians. Their hour is 

 directly the reverse of ours, it being noon with them when 

 it is midnight vviih us. Their longest day is our shortest 

 day, and their longest night our shortest night. The four 

 seasons are contrary, their summer being our winter, &c. 

 They are called Antipodes because iheir feet are opposite 

 l o our feet ; that is, they go with their heads downwards 

 in respect of us. 



The Amphiscii are so called because their shadows are 

 cast different ways at noon at different times of the year ; 

 that is, their shadow sometimes points to the north, and 

 sometimes to the south: therefore it 'is easy to perceive 

 that these people live in the torrid zone, that is, between 

 the tropics. 



A great circle is one the plane of which passes through 

 the centre of the spheres. 



A secondary to a great circle of the sphere is a great 

 circle passing through its poles. 



The angular distance of a heavenly body from a great 



