As he proceeded with his computation, it became more and more certain that this time the result was to harmonize with the observed facts.

As the story goes, he was so completely overwhelmed with emotion that he was forced to ask a friend to complete the simple calculation.

That story may well be true, for, simple though the computation was, its result was perhaps the most wonderful demonstration hitherto achieved in the entire field of science.

Now at last it was known that the force of gravitation operates at the distance of the moon, and holds that body in its elliptical orbit, and it required but a slight effort of the imagination to assume that the force which operates through such a reach of space extends its influence yet more widely.

That such is really the case was demonstrated presently through calculations as to the moons of Jupiter and by similar computations regarding the orbital motions of the various planets.