11 If looke what the part be of the ray perpendicular from the center unto the base of the greater section, so much the hemisphericall be increased, the whole shall be the greater section of the sphericall: But if it be so much decreased, the remainder shall be the lesser.
As in the example, the part of the third ray, that is, of 3/7, is from the center: such like part of the hemispherical 308, is 132. (For the 7, part of 308. is 44. And three times 44. is 132.) Therefore 132. added to 308. do make 440. for the greater section of the sphericall. And 132. taken from 308. doe leave 176. for the lesser section of the same.
12 The varium is a bossed surface, whose base is a
periphery, the side a right line from the bound of the toppe, unto the bound of the base.
13 A varium is a conicall or a cylinderlike forme.
14 A conicall surface is that which from the periphery beneath doth equally waxe lesse and lesse unto the very toppe.
Therefore
15. It is made by turning about of the side about the periphery beneath.