204 Dr. Forster on the Variation of the reJJeclive, 



to possess a greater power of penetrating through an imper- 

 fectly obscure atmosphere than others of equal apparent big- 

 ness, as the Pleiades and the Hyades. On the other hand, the 

 two small stars in Cancer, called Aselli by the Romans and 

 *Ovo» by the Greeks, were found to be obscured much before 

 the rest during the progressive condensation of the atmo- 

 sphere ; and their dimness and progressive disappearance, to- 

 gether with that of the nebula Presepe, was consequently re- 

 garded as the first sign of approaching rain, as is mentioned 

 byAratusinhisD/os^a, and which had been before observed 

 by Theophrastrus in his treatise TIsg\ o-wutuv !>=tu>v. The pas- 

 sage is exceedingly curious, and is as follows : 



'Ev to Kctgxlvu) 8uo Surrey; siinv, ol xa.Xo6jj.svoi ovoi, wv to phct%v 

 to vs$s\lov f; $<xtvy) xaAouju.sv>)- tqvto 8= ctv £o<p«S=j ysvYpcti, u8aT»xov. 



And afterwards he observes respecting the signs of rain : 



'H toO ovov QuTvrj si o-vvIo-txtou xai £op=ga ylvsTCti ^siftwva (r»j- 



jXXIVSi. 



Aratus in following up this observation makes a distinc- 

 tion between the indications of the northern and those of the 

 southern of the two stars, which we can hardly reconcile with 

 any conceivable hypothesis. 



El; ju-sv ■na.q fiogscto, voto> 8' linsqysTcti ctkXoc.' 

 Kcti to) /xsv xaXeWa» ovof pso-o-ri 81 ts Qutvyj, 

 "Hts xai e%onrlvris TravTrj Aio; suSiaovTOf 

 riviT a<pavro5 oXij* to) 8e d^OTsqco^sv lovref 

 'Ao-Tsqeg aXXijXwv avTOQ-yslov IvSaXXovTai' 

 Oux oXt'yco ys\\i.wvi tots xXv£ovt«i aqovoou. 

 E\ Se /xeXaiMjTai, to) 8° atrnV somoTse ooo~iv 

 ' Ao-Tsqsz. djAQiOTegoi 7Tigt •£ u8aT» anj/Aaivouv. 

 EJ 8' 6 ju-ev Ix fioqsu) QxTVYrf a/x^vrjva pas/vr 

 Astttoc swcc^kvouov, vo'rtoj 8* ovoj ayXaoj e»>), 

 As^sy^ai ct.vijx.oio votov fioqsw 8s jtx.aXa p£g^ 

 "£/X7raX(V ap^Xuo'svTi <pxswojj.svu) ts Soxeueiv. 



The peculiarity of this observation has struck many com- 

 mentators, and I find the following note appended to the 

 above passage. 



Meteorologica astronomicis confundit. Nam diverse harum 

 stellarum species, non a propria ipsarum atmosphcera, sed a 

 nostro a'ere ejficiuntur ,- quare, ergo, Ike, magis quam alice stel- 

 lae, per obscuritatem suam tempestates portendere possint ? Si 

 quidem ab ipsarum a'ere aut aliquo circa eas fieri possit speciei 

 variatio; quis credit tantam inter tarn remota sidera relationem 

 exist ere, ut aliquid, in stellis visum pluviam in mundo prcemo- 

 neret ? Scnsus est — Quod etiam confestim, ccelo sereno, Jit 



evanidum 



