16 The plaine of the side and halfe the base is the conicall surface.
As in the example next aforegoing, the side is 13. The halfe periphery is 15.5/7: And the product of 15.5/7 by 13. is 204.2/7. for the conicall surface. To which if you shall adde the circle underneath, you shall have the whole surface.
17 A cylinderlike forme is that which from the periphery underneath unto the the upper one, equall and parallell unto it, is equally raised.
Therefore
18 It is made by the turning of the side about two equall and parallell peripheries.
19 The plaine of his side and heighth is the cylinderlike surface.
As here the periphery is 22. as is gathered by the Diameter, which is 7. The heighth is 12. The base therefore is 38.1/2. And 38.1/2 by 12. are 462. for the cylinderlike surface. To which if you shall adde both the bases on each side, to wit, 38.1/2. twise, or 77. once, the whole surface shall be 539.