Glass positive of Hubble�s classification of �nebulae�
Glass positive of :- Hubble's classification of Nebulae (extra-galactic spirals). Shows: Sa.N.G.C.4594; SBa.N.G.C.2859; Sb.N.G.C.2841; Sc. N.G.C.5459; SBb.N.G.C.5850; SBc.N.G.C. 7479. Plate XV Mount Wilson Contribution No.324. 12"x15". Prepared from celluloid positive lent by Sir James Jeans