Le Verrier had been following the Uranus perturbations with great interest, while also compiling a painstaking record of the orbit of Mercury⁠—the innermost known planet. Le Verrier contacted observatories throughout France, but all of them rejected his request for telescope time. Undeterred, Le Verrier dispatched a detailed letter to a colleague outside of France⁠—Johann Galle, the director of the Berlin Observatory. Yet there was still the matter of the innermost planet, Mercury, that seemed to defy universal gravitation. Le Verrier amassed and organized over 40 years’ worth of records on Mercury’s orbit to fully characterize the nature of its perturbation.