This offers innumerable difficulties, for we only possess imperfect notices regarding the original design, and two doubtful drawings belonging to an uncertain period.

Still it is impossible to understand those changes in the Basilica of S.Peter's which were occasioned by the project of Julius, or to comprehend the immense annoyances to which the tomb exposed Michelangelo, without grappling with its details.

Condivi's text must serve for guide.

This, in fact, is the sole source of any positive value.

He describes the tomb, as he believed it to have been first planned, in the following paragraph:-- "To give some notion of the monument, I will say that it was intended to have four faces: two of eighteen cubits, serving for the sides, and two of twelve for the ends, so that the whole formed one great square and a half.