The following article was written expressly for the Crimson by Dr. Annie J. Cannon, Curator of Astronomical Photographs at the Harvard Observatory, where there is the largest and most valuable collection of astronomical photographs in the world. Dr. Cannon is recognized as the most eminent woman astronomer, and is the author of the Henry Draper Catalogue of Stellar Spectra, in which a quarter of a million stars are classified.

The Harvard Observatory

Some years ago, a Lehigh, University Professor told me this story concerning a Harvard graduate who was living in his home at that time and attending to the furnace. One day the Professor broached the subject of the Astronomical Observatory at Harvard. The young man looked puzzled and said, "Observatory? I don't know anything about such a place in Cambridge".

"What", exclaimed the Professor, "you never saw the famous Harvard Observatory, only a few blocks away from the College yard? You never heard of Professor Pickering, its distinguished Director these many years"?

"No", said the Harvard man, "in all my four years there, I never saw such a place nor ever heard of any name connected with it".

The Professor, wishing to mitigate a possible shock to my pride, said to me, "Never mind, I have just received a letter from my Harvard graduate, in which he writes,

"Please order a chord of wood for the furnice".

Nights Open to Students

With open nights now available to Harvard students, there can be no reason for lack of knowledge concerning your Observatory, or for failure to take advantage of the opportunity to look through one of its telescopes, or to see the great and unique collection of celestial photographs.

Nearly all astronomical investigations are now made by means of stellar photographs, of which there are 300,000 filed away in the stacks of the Harvard Observatory. Beginning as an experiment in 1850, when the first photograph of a star ever obtained was taken with the "incomparable" 15-inch telescope, starting anew in 1885 after the invention of the dry plate, the Harvard Collection of celestial photographs is the most complete in the whole world. Southern stars not visible in Cambridge were photographed in Arequipa, Peru, from 1891 to 1926, when the station was removed to Bloemfontein, South Africa.

Find New Galaxies

These photographs are mines of information concerning all portions of the sky, mines which have been only partially worked, and which still have rich veins awaiting the explorer. For instance a search is being made on Harvard plates for other galaxies than ours. These galaxies, far away from our own Milky Way system, are frequently of spiral shape, and can be readily detected by the careful observer. On photographs taken at Arequipa twenty-five years ago with the Bruce telescope, Miss Ames has found two thousand new galaxies.

By means of the Harvard photographs, certain comprehensive investigations have been undertaken here, which cannot at present be duplicated at any other Observatory. There is space to speak of two such problems; a survey of the whole sky for the discovery and study of variable stars, and for the classification of stars by means of their spectra.

Stars Are Inconstant

The Harvard photographs have proved to be the most prolific source for the discovery of variable stars, and also of the spectacular objects known as new stars or novae. Thus, 70 percent of the 7000 stars known to vary in brightness, and 67 percent of the 52 new stars which have flashed out since 1885, have been discovered at Harvard from observations of these photographs. And before 1885 few objects of either kind were known.