The volume contains an account of the foundation of the Institution; a description of the Observatory and Instruments, by G. W. Hough, A.M., the Director; and an Appendix. The establishment of the Institution was first proposed, in 1851, by Dr. J. H. Armsby; a subscription was raised, a large part of which was contributed by Mrs. Blandina Dudley, widow of the Honourable C. E. Dudley, and it was thereupon resolved to give to the institution the name of the Dudley Observatory. The Act of Incorporation was granted by the Legislature of the State of New York, in March, 1852. The building completed in 1854, on a site selected by Professor Mitchell, and from plans furnished by him. The Institution was inaugurated on the 28th of August, 1856, at the meeting of the American Association for the Advancement of Science. About 100,000 dollars was expended on the building, instruments, grounds, and other objects; and 50,000 dollars invested as a fund for the support of the Institution. The Observatory is situated in the north-western portion of the city of Albany, on an elevation about 150 feet above the mean tide in the Hudson River -- the site being, probably, one of the best that could have been chosen in the vicinity of the city; easy of access, and at the same time remote enough to be free from every disturbing influence. The horizon is clear and unobstructed in every direction; and the position is such as to preclude all possibility of interference if in future years the adjoining lands should be occupied for building purposes. In the plane of the meridian there is an uninterrupted view to the south for more than twelve miles. Advantage has been taken of this for the establishment of two meridian marks, distant six and twelve miles respectively. The grounds comprise about eight acres, and include the whole of the more elevated portion of the hill, which slopes off gradually in every direction. Two lithographic views are given, a distant and a near one; and there is also a plan of the grounds, and a ground-plan of the Observatory.

The principal instruments are, --

Equatoreal Refractor, by Mr. Fitz of New York; the object-glass 13 inches clear aperture; the focal length 15 feet 2 inches;

Olcot Meridian Circle, by Pistor and Martins;

Transit Instrument, by same makers;

Comet Seeker, by Alvin Clark; of 3 feet 6 inches focal length. and 4 inches clear aperture;

Chronograph, invented by Professor Mitchell, made by Messrs. Foster and Twitchet, Cincinnati;

Declinometer, invented by Professor Mitchell, by the same makers;

Charting Machine, made by Mr. Fasoldt, of Albany;

Automatic Registering and Printing Barometer, invented by Mr. Hough;

Swedish Calculating Machine of G. and E. Scheutz, purchased for the Observatory in the year 1856;

all elaborately described in the volume, with perspective views and drawings of the various details.

The Appendix comprises the Act of Incorporation, Board of Trustees, List of Donors, Catalogue of the Library, the Directors' Reports for the years 1862-63-64, and 65 : and observations of the Planets Mars and Neptune, of several of the Minor Planets, and of Comets.