Chap. 21.] ACCOUNT OF THE WOELD. 63 



half a tone, and thence a tone and a half to the zodiac. 

 Hence there are seven tones, which he terms the diapason 

 harmony \ meaning the whole compass of the notes. In 

 this, Saturn is said to move in the Doric time, Jupiter in the 

 Phrygian-, and so forth of the rest ; but this is a refinement 

 rather amusing than useful. 



CHAP. 21. (23.) — or THE DIMENSIONS OE THE WORLD. 



The stadium is equal to 125 of our Eoman paces, or 625 feet^. 

 Posidonius'* supposes that there is a space of not less than 

 40 stadia around the earth, whence mists °, winds and clouds^ 

 proceed ; beyond this he supposes that the air is pure and 

 liquid, consisting of uninterrupted light ; from the clouded 

 region to the moon there \b a space of 2,000,000 of stadia, 



^ " Aid Tratrujv, omnibus tonis contextam harmoniaoai." Hardouin in 

 Lemarre, ii. 287. 



2 These appellatioris appear to have originated from different nations 

 having assumed different notes as the foundation or commencement of 

 their musical scale. The Abbe Barthelemi informs us, that " the Dorians 

 executed the same air a tone lower than the Phrygians, and the latter a 

 tone still higher than the Lydians ; hence the denomination of the Dorian, 

 Phrygian, and Lydian modes." It appears to have been a general prac- 

 tice to employ the lowest modes for the slowest airs j Anacharsis's Travels, 

 iii. 73, 74. 



3 Hence the passus will be equal to 5 Roman feet. If we estimate 

 the Roman foot at 11*6496 EngUsh inches, we shall have the miliare of 

 8 stadia equal to 1618 EngHsh yards, or 142 yards less than an EngHsh 

 statute mole. See Adam's Roman Antiquities, p. 503 ; also the articles 

 Mihare and Pes in Smith's Dictionary of Greek and Roman Antiquities ; 

 and for the varieties of the stadium, as employed at different periods and 

 in different countries, see the article Stadium. The stadium which He- 

 rodotus employed in measurements of Babylon has been supposed to 

 consist of 490 Enghsh feet, while that of Xenophon and Strabo has been 

 estimated at 505 ; see Ed. Rev. xlviii. 190. The Abbe Barthelemi sup- 

 poses the stadium to be equal to 604 EngHsh feet ; Anach. Travels, vii. 284. 



^ There appears to have been two individuals of this name, who have 

 been confounded with each other ; the one referred to by Pliny was an 

 astronomer of Alexandria, who flomished about 260 years B.C. ; the other 

 was a native of Apamea, a stoic philosopher, who hvcd about two cen- 

 turies later ; see Aikin's Biog. in loco ; also Hardouin's Index Auctorum, 

 Lemaire, i. 209. 



* The terms in the original are respectively nubila and mibes. The 

 lexicographers and grammarians do not appear to have accurately dia- 

 oriminated between these two words. 



