As is apparant out the same definition of a varium.
12. A plaine made of the base and heighth is the solidity of a Cylinder.
The geodesy here is fetch'd from the prisma: As if the base of the cylinder be 38.1/2: Of it and the heighth 12, the solidity of the cylinder is 462.
This manner of measuring doth answeare, I say, to the manner of measuring of a prisma, and in all respects to the geodesy of a right angled parallelogramme.
If the cylinder in the opposite bases be oblique, then if what thou cuttest off from one base thou doest adde unto the other, thou shalt have the measure of the whole; as here thou seest in these cylinders, a and b.
From hence the capacity or content of cylinder-like
vessell or measure is esteemed and judged of. For the hollow or empty place is to be measured as if it were a solid body.