The area of an ellipse can be calculated by multiplying the semi-diameters together, and this product by 3 1/7 Thus, for an ellipse having diameters 24 in. and 18 in. the area equals -

12 x 9 x 3 1/7 = 12 X 9 X 22 / 7 = 339 1/7 sq . in

By applying the above calculations to what has been stated in Chapter XII (Conical Articles Of Short Taper)., the cubic contents, or number of gallons, that an elliptically conical vessel will hold can be obtained.