An equilateral cone circumscribed about a sphere ...Hawkins, John, Sir, 1719-1789Tacquet, Andre, 1612-1660From p. 27: [Tacquet's] words are these: 'An equilateral cone circumscribed about a sphere, and a right cylinder in like manner circumscribed about the same sphere, and the same sphere itself continue the same proportion ; to wit, the sesquialteral, as well as in respect of the solidity as of the whole superficies.mixed material