The Science of Living Things series demonstrates that Bobbie Kalman and her staff have turned out yet another informative and finely produced series of books. . . . this whole series would make a welcome addition to the elementary school library -- Kay Lehr, Fort Rouge School, Manitoba, Jan. 1999.
perpendicularity - the quality of being at right angles to a given line or plane (especially the plane of the horizon) oblongness, rectangularity - the property of being shaped like a rectangle.
viscosity n pl, -ties 1 the state or property of being viscous 2 (Physics) a the extent to which a fluid resists a tendency to flow b (Also called) absolute viscosity a measure of this resistance, equal to the tangential stress on a liquid undergoing streamline flow divided by its velocity gradient.