L 18 ] 
Riccioli fuppofeth, that the eclipfe foretold byThales 
happened the year before Chrift 585; and quotes both 
Theon and Cleomedes, in confirmation of the opinion,. 
Theon, perhaps, had Cleomedes’s words in view$ 
but neither of thefe authors have circumfiances 
enough to determine what eclipfe in particular they 
meant. The paflage of Theon is in his chapter con- 
cerning the moon’s parallax, where he fays, that 
Hipparchus, being in doubt whether the fun had any 
parallax at all, fuppofed, in the fir if book of his 
treatife concerning Magnitudes and Difiances, that 
the earth, in refpecf of the fun, was only a point ; 
from whence, by means of an eclipfe there fet down, 
by him, he framed two difiances of the fun, a lefs 
and a greater. Ev yxo tu A 7 rep'i y.eyeQuv xTro^v- 
f/.diwv XccuAclva (pxirorxevov to,. ExAa-'W HA/v, tv fx'tv 
ToTsiregt tgv i: AAv;<r7ror/si' totto/? oA« HA/a 
yeysi'eyJvm'xtocre uriSev ccu.a Trtt^x^ouvi^ tv AA i^xvSpeux, 
St tv xaT AtyvTr.ov rx A y.xhi^x 7r^L7r%fxo^/.x tv$ 
Sixrxfigv !xA£Aoi7TOT<x.« 
All then that is here faid is, that the eclipfe made 
ufe of by Hipparchus was total at the Hellefpont; 
but at Alexandria in Egypt a little more than 5 digits 
only. But he hath neither given us the aera of Nabo- 
naiiar, the place of the luminaries, nor any one cir- 
c mfiance befides, by which we might form any con- 
c’ufion what year this eclipfe was in. 
Cleomedes, who perhaps faw the fame treatife of 
Hipparchus, is as uncircumftantial as Theon. He 
fays only, that the diameter of the moon’s fhadow at 
the earth is fomething more than 4,000 fiadia. And 
to confirm this aflertion, he fays, yeycvs Si ^ oLulv 
Trifvon fTrt tvs xxlx tov HA<oi’ bxAr< 4 fc& ^> 05 &Aos IIOTE 
3 
tv 
