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OF THE SYSTEMS OF PTOLEMY,

the threats of ignorant enthusiasts, and the ter-rors of the inquisition, it has gradually prevailedever since, and is now universally received byall the learned throughout Europe.

Towards the end of the sixteenth century,and about the beginning of the next, thosegreat men Galileo and Kepler, particularly dis-tinguished themselves in the defence of thisdoctrine; and by means of the telescope, whichwas the invention of that time, made manynew and surprizing discoveries in the heavens.By applying this instrument to the planets,Galileo first observed, that the phases of Venuswere like the monthly phases of the moon; andfrom thence inferred that she revolved roundthe sun as a center. He also proved the revo-lution of the sun on his axis, from the motionof his spots; and thence the diurnal rotation ofthe earth became more credible. The four satel-lites which attend Jupiter, in his revolution aboutthe fun, represented likewise, in miniature, ajust image of the great solar system, and ren-dered it more easy to conceive how the moonmight attend the earth, as a satellite, in herannual revolution. In short, by his discoveringhills and cavities in the moon, and spots in thefun, constantly varying, he proved, clearly, thatthere was not so great a difference betweenCelestial and sublunary bodies as philosophershad vainly imagined.

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