CHAP. 1. 6. OP CLOUDS. 19 



or to its relative position. These appearances 

 are best seen in the morning and evening, 

 when the sun is near to the horizon. They 

 have been well described by the ancient poets,* 

 who have likewise spoken of them as precursors 



* VIRGIL, speaking of the prognostics of rain, alludes to 

 several appearances which must be ascribed to the interven- 

 tion of this cloud. 



Sol quoque et exoriens et quum se condit in undas 

 Signa dabit, solem certissima signa sequuntur 

 Et quae mane refert et quae surgentibus astris, 

 Ille ubi nascentem maculis variaverit ortum 

 Conditus in nubem medioque refugerit orbe 

 . Suspecti tibi sint imbres, namque urguet ab alto 

 Arboribusque satisque notus pe"corique sinister, 

 Aut ubi sub lucem densa inter nubila sese 

 Diversi rumpent radii, aut ubi pallida surget 

 Tithoni croceum linquens Aurora cubile 

 Heu male turn mitis defendent pampinus uvas 

 Tarn multa in tectis crepitans salit horrida grando. 

 Hoc etiam emenso quum jam decedat Olympo 

 Profuerit meminisse magis, nam saepe videmus 

 Ipsius in voltu varios errare colores 

 Caeruleus pluviam denunciat, igneus Euros 

 Sin maculae incipient rutilo inmiscerier igni 

 Omnia turn pariter vento nimbisque videbis 

 Fervere : non ilia quisquam me nocte per altum 

 Ire neque a terra moneat convellere funem, 

 At si quum referetque diem conditque relatnm 



c 2 



