Secondly, let the parallelogram A K I B not be rectangled; the strait line I B will nevertheless press the point B perpendicularly in the strait line B E; and the strait line L G will press the point G perpendicularly in the strait line G H; and all the rest of the strait lines which are parallel to I B will do the like. Whatsoever therefore the moment be which is assigned to the strait line I B, as here, for example, it is supposed to be B E, if A E be drawn, the moment of the whole parallelogram A I will be the triangle A B E; and the moment of the part A L will be the triangle A G H. Wherefore the moment of any ponderant, which has its sides equally applied to the beam, whether they be applied perpendicularly or obliquely, will be always to the moment of a part of the same in such proportion as the whole triangle has to a part of the same cut off by a plane which is parallel to the base. [Sidenote: The diameter of equiponderation of figures which are deficient according to commensurable proportions of their altitudes and bases, divides the axis, so that the part taken next the vertex is to the other part as the complete figure to the deficient figure.] 9. The centre of equiponderation of any figure, which is deficient according to commensurable proportions of the altitude and base diminished, and whose complete figure is either a parallelogram or a cylinder, or a parallelopipedum, divides the axis, so, that the part next the vertex, to the other part, is as the complete figure to the deficient figure. For let C I A P E (in fig. 5) be a deficient figure, whose axis is A B, and whose complete figure is C D F E; and let the axis A B be so divided in Z, that A Z be to Z B as C D F E is to C I A P E. I say, the centre of equiponderation of the figure C I A P E will be in the point Z.