THE HARVARD OBSERVATORY.

In a recent issue of the well-known English astronomical periodical, the Observatory, Mr. A. M. W. Downing of Greenwich reviews a paper lately published in the memoirs of the American academy by Prof. W. A. Rogers of Cambridge, upon the "Harvard College Observatory Catalogue of Stars for 1875." The article by Prof. Rogers is a comparison of the catalogue with the fundamental systems of Anwers, Safford, Boss and Newcomb. This comparison, according to Mr. Downing, shows the excellence of the Harvard College Observatory star places, and goes far to justify the great relative weight which is assigned to them by American and German astronomers when combining them with places of stars determined at other observatories. The fundamental systems referred to comprise catalogues of the principal stars which have been independently formed, for the most part from complete discussions of all the data available previous to the year 1872, and are therefore well adapted to test severely the accuracy of any series of observations, and Prof. Rogers is to be congratulated on the manner in which the observations made by him and his assistants stand the test.