£.ET. II.

OF THE EARTH.

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and the earth being, at this time, interposed*between them, the moon must either wholly,or in part, become obscure. And since in everyeclipse of this kind, which is not total, the ob-scure part always appears to be bounded by acircular line, the earth itself, for that reason,must be spherical. Because it is evident, thatnone but a spherical body can, in all situations,cast a circular shadow.

Nor are the little unevennesses on the earth’ssurface, arising frpm hills and vallies, any ma-terial objection to its being considered as around body; since the highest mountains we areacquainted with, bear a less proportion to thewhole bulk of the earth, than the small risingson the coat of an orange bear to that fruit; or agrain of sand, to an artificial globe of a foot indiameter. And accordingly we find, that thesetrifling protuberances occasion no irregularitiesin the shadow of the earth, during the r dme ofa lunar eclipse; but that the circumference ofit ahyays appears to be even and regular, as ifcast by a body perfectly globular.

A number of other proofs might be given tqthe fame purpose; but these are the most po-pular, and such as I apprehend must entirelyconvince every impartial enquirer, whose objectis truth, and whose mind is unclouded bysuperstition, or an obstinate attachment to early;options and vulgar prejudices. I mention this' C 3 the