That the Earth may be a Planct. the Equator, in one beating of the Pulſe, muſt
move 2528 of theſe miles.

’Tis the Affertion of Clavius, that though the diſtance of the Orbs, and ſo conſe-
quently their ſwiftneſs, ſeem to be altoge-
ther incredible; yet it is rather far greater
in it ſelf, than Aſtronomers uſually ſuppoſe
it; and yet (ſaith he) according to the
common Grounds, every Star in the Equa-
tor, muſt move 42398437 {1/2} miles in an hour. And though a Man ſhould conſtantly travel
40 miles a day, yet he would not be able to
go ſo far as a Star does in one hour, under
2904 Years: Or if we will ſuppoſe an Ar-
row to be of the ſame ſwiftneſs, then muſt
it compaſs this great Globe of Earth and
Water 1884 times in an hour. And a Bird
that could but fly as faſt, might go round
the World ſeven times in that ſpace, whilſt
one could ſay, Ave Maria, gratia plena, Do-
minus tecum.

Which though it be a pretty round pace,
yet you muſt conceive that all this is ſpoken
only of the eighth Sphere; and ſo being
compared to the ſwiftneſs of the Primum
Mobile, is but a ſlow and heavy Motion.

For (ſaith the ſame Author) the thick-
neſs of each Orb is equal to the diſtance of
its concave Superſicies from the Centre of
the Earth. Thus the Orb of the Moon does
contain as much ſpace in its thicknefs, as
there is betwixt the neareſt part of that
and the Centre. Thus alſo the eight Sphere