[1] The Custer Institute is Long Island's oldest public observatory, and was founded in 1927 by Charles Wesley Elmer (co-founder of the Perkin-Elmer Optical Company) and fellow amateur astronomers.

The name was adopted to honor the hospitality of Mrs. Elmer, the grand-niece of General George Armstrong Custer.

The telescope's dialyte lenses make it apochromatic, providing enhanced views of the solar system and deep space objects.

The telescope is attached to a computer-controlled Fornax 152 equatorial mount, permitting easy aiming and object tracking.

It contains National Geographic, Sky & Telescope, Astronomy, and Scientific American magazines dating back numerous decades.