anſwerable to the ſeveral diſtances of the

Planets from one another.

Thus a Cube will meaſure the diſtance be-

twixt Saturn and Jupiter; a Pyramis or Te-

traëdron, the diſtance betwixt Jupiter and

Mars ; a Dodecaëdron, the diſtance betwixt

Mars and the Earth; an Icoſaëdron, the diſtance

betwixt the Earth & Venus; and an Octoëdron,

the diſtance betwixt Venus & Mercury: that

is, if we conceive a Circumference deſcri-

bed immediately without the Cube, and a-

nother within it, the diſtance between theſe

two, will ſhew what proportional diſtance

there is betwixt the Orb of Saturn, and

that of Jupiter. Thus alſo, if you con-

ceive a Circumference deſcribed on the out-

ſide of a Pyramis, or Tetraëdron, and ano-

ther within it, this will ſhew ſuch a propor-

tional diſtance, as there is betwixt the Orb

of Mars, from that of Jupiter. And ſo of

the reſt.

Now if any ask why there are but ſix

Planetary Orbs? Keplar anſwers, Zuia non

oportet plures quàm quinque proportiones eſſe,

totidem nempè quot regularia ſunt in Matheſi

corpora. Sex autem termini conſummant hunc

proportionum numerum: Becauſe there are

but five proportions, ſo many as there are

regular Bodies in Mathematicks, each of

whoſe Sides and Angles are equal one to

another. But now there are ſix terms re-

quired to conſummate this number of pro-

portions; and ſo conſequently, there can

be but ſix primary Planets.