As here thou seest the parallell plaines aeio, and uysr, cut by the plaine ljvf, the common sections lj, and fv, shall also be parallell: Otherwise they themselves, and therefore also the plaines in which they are, shall meete, as in the point t, which is against the grant.
The twenty second Booke, of P. Ramus Geometry, Of a Pyramis.
1. The axis of a solid is the diameter about which it is turned, e 15, 19, 22 d xj.
The Axis or Axeltree is commonly thought to be proper to the sphere or globe, as here ae: But it is attributed to other kindes of solids, as well as to that.
2. A right solid is that whose axis is perpendicular to the center of the base.
Thus Serenus and Apllonius doe define a Cone and a Cylinder: And these onely Euclide considered: Yea and indeed stereometry entertaineth no other kinde of solid but that which is right or perpendicular.