In 1857 the post of first assistant at the Royal Greenwich Observatory became vacant and Routh was invited by Airy, the Astronomer Royal, to visit the Observatory so that he might be offered the post.
Sa 1857 ang mga post ng unang assistant sa Royal Greenwich obserbatoryo ay naging laman at Routh ay inimbitahan ng Airy, ang Astronomer Royal, upang bisitahin ang obserbatoryo na kaya siya maaaring inaalok ang mga post.