. . . Cyclopum educta caminis Mœnia conspicio, atque adverso fornice portas. . . . . . His demum exactis, perfecto munere Divæ, Devenere locos lætos et amœna vireta Fortunatorum nemorum sedesque beatas. Largior hic campos æther et lumine vestit Purpureo: solemque suum, sua sidera norunt. VIRGIL, _Æn._ vi. 630. They leave at length the nether gloom, and stand Before the portals of a better land: To happier plains they come, and fairer groves, The seats of those whom heaven, benignant, loves; A brighter day, a bluer ether, spreads Its lucid depths above their favored heads; And, purged from mists that veil our earthly skies, Shine suns and stars unseen by mortal eyes. {{255}} INTRODUCTION. _Of Formal and Physical Astronomy._ WE have thus rapidly traced the causes of the almost complete blank which the history of physical science offers, from the decline of the Roman empire, for a thousand years. Along with the breaking up of the ancient forms of society, were broken up the ancient energy of thinking, the clearness of idea, and steadiness of intellectual action. This mental declension produced a servile admiration for the genius of the better periods, and thus, the spirit of Commentation: Christianity established the claim of truth to govern the world; and this principle, misinterpreted and combined with the ignorance and servility of the times, gave rise to the Dogmatic System: and the love of speculation, finding no secure and permitted path on solid ground, went off into the regions of Mysticism.