The coefficients in the series were known as ' Laplace coefficients' but the drawback of the method was that it only worked for circular orbits. Newcomb showed how to extend Laplace 's series to give a perturbing function in the case of elliptical orbits by introducing differential operators which act on the Laplace coefficients.
Ang coefficients sa serye ay kilala bilang 'Laplace coefficients' ngunit ang mga sagabal ng mga paraan na ito lamang ay nagtrabaho para sa pabilog orbits. Newcomb ay nagpakita kung paano mag-extend Laplace 's serye na magbigay ng isang perturbing function sa kaso ng tambilugin orbits nagpapakilala sa pamamagitan ng kaugalian operator na kumilos sa mga Laplace coefficients.