the name of a tract or general problem, written by the ancient geometer Apollonius. None of this work has come down to us, excepting some extracts, and an account of it, by Pappus, in the Preface to the 7th book of his Mathematical Collections. He there says that the general problem was "To cut an infinite right line in one point, so that, of the segments contained between the point of section sought, and given points in the said line, either the square on one of them, or the rectangle contained by two of them, may have a given ratio, either to the rectangle contained by one of them and a given line, or to the rectangle contained by two of them."