in 1935, and the Rhodes lectures at Oxford in 1936. In 1948 he was elected an honorary fellow of Queen’s College, Oxford, in recognition of his notable contributions to astronomy.

Hubble’s work was characterized not only by his acuity as an observer but also by boldness of imagination and the ability to select the essential elements in an investigation. In his careful assessment of evidence he was no doubt influenced by his early legal training. He was universally respected by astromers, and on his death N. U. Mayall expressed their feelings when he wrote: “It is tempting to think that Hubble may have been to the observable region of the universe what the Herschels were to the Milky Way and what Galileo was to the solar system.”

BIBLIOGRAPHY

I. Original Works.Hubble’s Halley lecture, delivered at Oxford in 1934, was published as Red Shifts in the Spectra of Nebulae (Oxford, 1934). His Silliman lectures, delivered at Yale University in 1935, appeared as The Realm of the Nebulae (Oxford, 1936). His Rhodes memorial lectures, delivered at Oxford University in 1936, were published as The Observational Approach to Cosmology (Oxford, 1937). His Penrose memorial lecture was published as “Explorations in Space: The Cosmological Program for the Palomar Telescopes,” in Proceedings of the American Philosophical Society, 95 (1951), 461–470; and his George Darwin lecture as “The Law of Red-Shifts,” in Monthly Notices of the Royal Astronomical Society, 113 (1953), 658–666.

At the time of his death Hubble was preparing an atlas of photographs to illustrate his revised classification of the galaxies based on