16 PLi:!fT's NATUEAL HISTOET. [Book II." 



especially wlien that is so extensive. It is madness, perfect 

 madness, to go out of this world and to search for what is 

 beyond it, as if one who is ignorant of his own dimensions 

 could ascertain the measure of any thing else, or as if the 

 human mind could see what the world itself cannot contain. 



CHAP. 2. (2.) — or THE rOEM OF THE WOELD^ 



That it has the form of a perfect globe we learn from 

 the name which has been uniformly given to it, as well as 

 from numerous natural arguments. Por not only does a 

 figure of this kind return everywhere into itself^ and sustain 

 itself, also including itself, requiring no adjustments, not 

 sensible of either end or beginning in any of its parts, and is 

 best fitted for that motion, with which, as will appear here- 

 after, it is continually turning round ; but still more, because 

 we perceive it, by the evidence of the sight, to be, in every 

 part, convex and central, which could not be the case were 

 it of any other figure. 



CHAP. 3. (3.) — OE ITS NATTJEE; WHENCE THE NAMEISDEEIYED. 



The rising and the setting of the sun clearly prove, 

 that this globe is carried round in the space of twenty -four 

 hours, in an eternal and never-ceasing circuit, and with in- 



^ I may remark, that the astronomy of our author is, for the most 

 part, derived from Aristotle ; the few points in which they differ vnH be 

 stated in the appropriate places. 



2 This doctrine was maintained by Plato in his Timseus, p. 310, and 

 adopted by Aristotle, De Coelo, hb. ii. cap. 14, and by Cicero, De Nat. 

 Deor. ii. 47. The spherical form of the world, ovpavbsy and its circidar 

 motion are insisted upon by Ptolemy, in the commencement of his astro- 

 nomical treatise MeydXrj ^vvra^is. Magna Constructio, frequently re- 

 ferred to by its Arabic title Almagestum, cap. 2. He is supposed to have 

 made his observations at Alexandria, between the years 125 and 140 a.d. 

 His great astronomical work was translated into Arabic in the year 827 ; 

 the original Greek text was first printed in 1538 by Grynseus, with a 

 commentary by Theon. George of Trebisond pubUshed a Latin version 

 of it in 1541, and a second was pubhshed by Camerarius in 1551, along 

 with Ptolemy's other works. John Muller, usually called Regiomontanus, 

 and Purback pubhshed an abridgement of the Almagest in 1541. For an 

 account of Ptolemy I may refer to the article in the Biog. Univ. xxxv. 

 263 et seq., by Delambre, also to Hutton's Math. Diet,, in loco, and to 

 the liigh character of him by Whewell, Hist, of the Inductive Sciences, 

 p. 214. 



