The avian egg: Geometrical description and calculation parameters

It is shown that an egg profile can be represented mathematically in terms of its length L and maximum breadth B by the equation y = +/- 1.5396 B(L-0.5 x (1.5) - x(2))(0.5)/L where x is the coordinate along the longitudinal axis and y the transverse distance to the profile. Calculation using the equation for the solid of revolution allows estimation of the egg volume, surface area, long circumference length, normal projected area of the egg, radius of curvature and angle between the long axis and the tangent to the shell at any point. To minimize calculation errors, a method is proposed where by the egg profile is transformed into a mathematical expression using a modified value for the maximum breadth B. This is done by requiring equality of length of the longitudinal axis and either the long circumference length, the volume, or the normal projected area. In the modified form, calculation errors for surface area and volume did not exceed 5% for the "average egg". (C) 1997 Silsoe Research Institute.