The various methods will be considered first for the trapezette, the extensions to the briquette being only treated briefly.

The ordinates of this new briquette at the points of intersection of x =x 0, x = xi,.

A briquette may therefore be defined as a solid figure bounded by a pair of parallel planes, another pair of parallel planes at right angles to these, a base at right angles to these four planes (and therefore rectangular), and a top which is a surface of any form, but such that every ordinate from the base cuts it in one point and one point only.

y where K-=4, X qth moment with regard to plane y =o, Lm yn X pth moment with regard to plane x =o, and R is the volume of a briquette whose ordinate at (x,.,y s) is found by multiplying by pq x r P - 1 ys 4-1 the volume of that portion of the original briquette which lies between the planes x =xo, y =yo, y = ys.

The figure is such as would be produced by removing a piece of a rectangular prism, and is called a briquette.