The whole establishment was to have been placed under the supeiintcndence of the eminent Professor Ormsby M. Mitchel, of Ohio. The Civil War broke out, and Mr. Mitchel, animated by patriotic zeal for the salvation of his country, entered the military service, for which he had been educated at West Point, and was made a general officer. While in command of the "Department of the South" at Beaufort, South Carolina, he died from the effects of yellow fever.

The Dudley Observatory is upon the highest summit of the grounds, and commands an extensive view of the Hudson and the adjacent country. It is cruciform, with a front of about eighty feet, and a depth of seventyfive feet. Its massive walls are of brick, faced with brown freestone. All the arrangements within, for the use of instruments, are very perfect. In a large niche opposite the entrance door is a marble bust of Mr. Dudley, by Palmer, the eminent sculptor, on the pedestal of which is the following inscription : --

CHARLES ¥. UUDLEV,

liX BLANDINA, HIS WIFE.

DEDICATED TO THE ADVANCEMENT OF

ASTEONOMT.

In the Clock-room of the Observatory is the apparatus by which a "timeball" on the top of the State Capitol, a mile distant, is dropped at precisely twelve o'clock each day, and bells are also rung at the same instant in the senate and assembly chambers. The ball is seen in our sketch of the Capitol. It is f jiir and a half feet in diameter, is mounted on the flag-staff, and is raised each day at ten minutes before twelve. The force of the fall is broken by spiral springs at the foot of the flag-staff. Another but smaller time-ball is dropped at the same instant in Broadway, in front of the telegraph-office, and hundreds of persons may be seen daily holding their watches at the approach of the meridian moment, to regulate them by this unerring indicator.