Cambridge sketches
Estelle M. H. Merrill, Ed.

On our way out of this building we must step into the library for a moment. Here are between seven and eight thousand bound volumes and nearly ten thousand pamphlets. A considerable proportion of these books and pamphlets contain records of observations made at different times all over the world. The Harvard Annals alone fill a long row of thick quarto volumes. Those dry looking pages of statistics contain many interesting secrets for future discovery.

Now let us see what are the other buildings. A good sized wooden house at a little distance, serves as a shop, and there are a number of small buildings scattered about, most of them domed. Most of these contain photographic instruments. Off to the right, a little way down the slope, is a brick building used for the storage and examination of photographic plates.

Within a few years, photography of the heavens has come to have a leading place as a means of astronomical research. At Harvard, several telescopes are kept busy with photographic work. The advantages of this method are obvious. Unlike the human eye, so soon wearied, the photographic plate sees the more, the longer it is exposed. There is reason to believe that if a telescope could be kept pointed night and day, with perfect accuracy, upon any source of light anywhere in the universe, it would finally record it on the sensitive plate.

Nearly all kinds of astronomical work usually accomplished by visual observations can be done more or less admirably, or can be assented greatly, by the photographic telescope. For instance, the