Graham, A.; New Planet, Monthly Notices of the Royal Astronomical Society, Vol. 8, No. 6 (dated April 14, 1848!), p. 146 (signed April 29, 1848; the discovery was first announced on April 27)
Graham, A.; Metis, Monthly Notices of the Royal Astronomical Society, Vol. 8, No. 7 (dated May 12, 1848), pp. 147 – 150)