Authors:
Johanes Tobias Mayer (1723-1762) & Johann Heinrich Lambert (1728-1777) & Moses Harris (1730-1785)
Diagrams developed to represent color systems. In 1758, Mayer developed a system of constructing and naming many of the possible colours. Lambert extended this with a 3D pyramid indicating "depth'' (saturation).
Theory of measurement error as deviations from regular graphed line. (Lambert made the observation that "a diagram does incomparably better service here than a table.''cite[p. 204]{Tilling:1975}