Speakers for the Harvard College Observatory "Astronomical Fair" were announced last night by Dr. Harlow Shapley, director of the Observatory. The "Fair" will swing into action at 7 o'clock tonight, and will be continued for three successive evenings at the Observatory on Garden Street. All proceeds are to go to unemployment relief in Cambridge.

Tonight's lecture will be given at 7.30 o'clock and repeated at 9.30 o'clock by Dr. D. H. Menzel, noted authority on the atmosphere of the sun. Taking as his topic "The Puzzle of the Planets," he will expound, among other things, the secret of the canals on Mars and the possibility of life there, the frozen clouds of Jupiter, and the rings of Saturn. He will also discuss the discovery of Pluto, and the speculations it has incited as to the number of planets and the boundary of the sun's domain

Tomorrow evening the lecture will be given by Dr. B. J. Bok, Willson Teaching Fellow, on "Our Changing Universe."

Dr. Shapley will speak on the last night of the affair about "The Metagalaxy and the Expanding Universe."