But most by Numbers judge a Poet's song; And smooth or rough, with them is right or wrong: In the bright Muse though thousand charms conspire, Her voice is all these tuneful fools admire; 340 Who haunt Parnassus but to please their ear, } Not mend their minds; as some to Church repair, } Not for the doctrine, but the music there. } These equal syllables alone require, Tho' oft the ear the open vowe's tire; 345 While expletives their feeble aid do join; And ten low words oft creep in one dull line: While they ring round the same unvary'd chimes, With sure returns of still expected rhymes; Where-e'er you find "the cooling western breeze," 350 In the next line, it "whispers through the trees:" If crystal streams "with pleasing murmurs creep," The reader's threaten'd (not in vain) with "sleep:" Then, at the last and only couplet fraught With some unmeaning thing they call a thought, 355 A needless Alexandrine ends the song That, like a wounded snake, drags its slow length along. Leave such to tune their own dull rhymes, and know What's roundly smooth or languishingly slow; And praise the easy vigour of a line, 360 Where Denham's strength, and Waller's sweetness join. True ease in writing comes from art, not chance, As those move easiest who have learn'd to dance. 'Tis not enough no harshness gives offence, The sound must seem an Echo to the sense: 365 Soft is the strain when Zephyr gently blows, And the smooth stream in smoother numbers flows; But when loud surges lash the sounding shore, The hoarse, rough verse should like the torrent roar: When Ajax strives some rock's vast weight to throw, 370 The line too labours, and the words move slow; Not so, when swift Camilla scours the plain, Flies o'er th' unbending corn, and skims along the main. Hear how Timotheus' varied lays surprize, And bid alternate passions fall and rise! 375 While, at each change, the son of Libyan Jove Now burns with glory, and then melts with love, Now his fierce eyes with sparkling fury glow, Now sighs steal out, and tears begin to flow: Persians and Greeks like turns of nature found, 380 And the world's victor stood subdu'd by Sound! The pow'r of Music all our hearts allow, And what Timotheus was, is DRYDEN now.