materiae causas: quae vis animaverit astra impuleritque choros; quo vivat machina motu; sidera cur septem retro nitantur in ortus obluctata polo; variisne meatibus idem arbiter an geminae convertant aethera mentes; sitne color proprius rerum, lucisne repulsu 106 eludant aciem; tumidos quae luna recursus nutriat Oceani; quo fracta tonitrua vento, quis trahat imbriferas nubes, quo saxa creentur grandinis; unde rigor nivibus; quae flamma per auras 110 excutiat rutilos tractus aut fulmina velox torqueat aut tristem figat crinita cometem. Iam tibi compositam fundaverat ancora puppim, telluris iam certus eras; fecunda placebant otia; nascentes ibant in saecula libri: 115 cum subito liquida cessantem vidit ab aethra Iustitia et tanto viduatas iudice leges. continuo frontem limbo velata pudicam deserit Autumni portas, qua vergit in Austrum Signifer et noctis reparant dispendia Chelae. 120 pax avibus, quacumque volat, rabiemque frementes deposuere ferae; laetatur terra reverso numine, quod prisci post tempora perdidit auri. illa per occultum Ligurum se moenibus infert et castos levibus plantis ingressa penates 125 invenit aetherios signantem pulvere cursus, quos pia sollicito deprendit pollice Memphis: * * * * * Page 347 of the elements and the causes of matter’s ceaseless change; what influence has given life to the stars, moving them in their courses; what quickens with movement the universal frame. Thou tellest why the seven planets strive backward towards the East, doing battle with the firmament; whether there is one lawgiver to different movements or two minds govern heaven’s revolution; whether colour is a property of matter or whether objects deceive our sight and owe their colours to reflected light; how the moon causes the ebb and flow of the tide; which wind brings about the thunder’s crash, which collects the rain clouds and by which the hail-stones are formed; what causes the coldness of snow and what is that flame that ploughs its shining furrow through the sky, hurls the swift thunderbolt, or sets in heaven’s dome the tail of the baleful comet.