“…Huyghens' assistant, J. Richer, noticed in 1671 in French Guinea that in order to acquire here a conformity between the time as measured by his pendulum clock and the motion of the Sun, he had to shorten it from its length in Paris (see on this (Jammer 1961, 73-74) and (Sarlemijn 1993». What do the coefficients Ol and g have in common?…”