Come faithful Siren! chaste seducer! say, What laws controul thee, and what powers obey. Know first, that light displays and shade destroys Refulgent Nature's variegated dyes. Thus bodies near the light distinctly shine With rays direct, and as it fades decline. 365 Thus to the eye oppos'd with stronger light They meet its orb, for distance dims the sight. 'Learn hence to paint the parts that meet the view In spherick forms, of bright and equal hue; 371 Dedecori fuit unquam ; illi sed semper honori, 265 Laudibus et meretis; hanc ergo nosse juvabit. Lux varium, vivumque dabit, nullum umbra, colorem. Quo magis adversum est corpus, lucique propin quum. Clarius est lumen; nam debilitatur eundo. Quo magis est corpus directum, oculisque propin quum, Conspicitur melius; nam visus hebescit eundo. u Ergo in corporibus, quæ visa adversa, rotundis, 270 t XXXI. The conduct of u XXXI. Tonorum Luthe Tints of Light and Sha- minum et Umbrarum ratio. While, from the light receding or the eye, The sinking outlines take a fainter dye. 380 (Tho' sure from more than three confusion springs,) 385 One globe of light and shade o'er all she flings; Integra sunt, extrema abscedant perdita signis Clara gradu, nec adumbrata in clara alta repentè 275 390 And as the centre of some convex glass, 395 As is the Sculptor's, such the Painter's aim, Their labour different, but their end the same; What from the marble the rude chissel breaks, The softer pencil from the canvass takes: 400 Sintque ita discreti inter se, ratione colorum, Luminis, umbrarumque, antrorsum ut corpora clara Obscura umbrarum requies spectanda relinquat; Claroque exiliant umbrata atque aspera campo. 285 Ac veluti in speculis convexis, eminet ante 290 Mente modoque igitur plastes, et pictor, eodem Dispositum tractabit opus; quæ sculptor in orbem 404 And skill'd remoter distances to keep, In silver clouds in ether's blue domain, If chance some solid substance claim a place, 410 Jam signata minùs confusa coloribus aufert: y Densa figurarum solidis quæ corpora formis 295 300 * XXXII. Dense and op- y XXXII. Corpora densa aque bodies with translucent et opaca translucentibus. ones. Rough let it swell and boldly meet the sight, Mark'd with peculiar strength of shade and light; There blend each earthly tint of heaviest sort, 415 Light and pellucid from that substance fly. But yield to one alone the power to blaze 420 In translucendi spatio ut super aëra, nubes, Ut distincta magis firmo cum lumine et umbra, • Non poterunt diversa locis duo lumina eâdem In tabulâ paria admitti, aut æqualia pingi : Z XXXIII. There must not be two equal Lights in the 310 a XXXIII. Non duo ex cœlo Lumina in tabulam æ |