LET. IV. TyCHO BrAHE, AND CoPERNICtIS. 59

as is agreeable to modern discoveries. Theyalso taught that every star was a world, havingeach of them something corresponding to ourearth, such as air and water; and that the moon,in particular, was inhabited by larger and morebeautiful animals than those of our globe. Thissystem, however, was so extremely opposite tothe prejudices of sense and opinion, that it nevermade any great progress in the ancient world.

The philosophers of antiquity, despairing ofbeing able to overcome ignorance by reason, setthemselves to adapt the one to the other, andto form a reconciliation between them. >

The most celebrated of those who undertookto establilh an hypothesis of this kind, and todefend it with a strew of reason and argument,was Ptolemy, an Egyptian philosopher, wholived in the time of the emperor Adrian, aboutan hundred and thirty years after Christ. Hesupposed with the vulgar, who measure everything by their own conceptions, that the earthwas fixed immoveably in the center of the uni-PU. fig-verse; and that the Moon, Mercury, Venus,the Sun, Mars, Jupiter, and Saturn, revolvedround it in the order they are mentioned. Abovethese was the firmament of the fixed stars, thecrystalline orbs, the primum mobile, and lastof all, the cœlum empyrium, or heaven of hea-vens. All these vast orbs were imagined tomove round the earth once in twenty-four

hours,