Under the auspices of the Bond Astronomical Club, a series of four "Open Nights" will be held at the Harvard Observatory, with the first meeting scheduled for this evening at 7.45 o'clock, when Professor E. S. King will deliver a short, non-technical talk on "The Moon." After his address there will be, weather permitting, telescopic observations of celestial objects. Exhibits showing the work of the Observatory will be explained by members of the club.

On Monday evening Dr. A. J. Cannon will continue the series with a lecture on "The Stars." Miss H. B. Sawyer, speaking next Thursday, will have "The Planets" as her topic; while as the conclusion of the "Open Nights," on April 30, C. B. Andrews '25 will discuss "The Sun."

Tickets for these meetings must be obtained in advance by sending a self-addressed, stamped envelope to the observatory, stating for which night the tickets are desired. Applicants will be assigned tickets for one night only.