atory of Philadelphia was furnished in 1840.
The West Point Observatory about 1841.
The Tuscaloosa Observatory in 1843.
The Washington Observatory about 1844.
The Georgetown, D. C., Observatory in 1844.
The Cincinnati Observatory in 1845.
The Cambridge Observatory in 1847.
The Amherst Observatory in 1847.
Dartmouth, Newark, Shelbyville, Ky., Buffalo, Michigan University, Albany, and Hamilton College, have also observatories.
A good article on the astronomical observatories of the United States may be found in Harper's Magazine, June, 1856.
See also Observations at the Washington Observatory, volume for 1845.
For more full details than in the articles named, see Chambers's Astronomy; Dr. Pearson's Practical Astronomy; Loomis's Practical Astronomy; Simm's Treatise on Instruments; Heather on Mathematical Instruments.
One with panes or slides having perforations whose relative size and position represent stars in a given field