The observatory was built in 1854 for Ira Young, Professor of Natural Philosophy, to designs drawn up by his brother Ammi B. Young, then supervising architect of the United States Treasury Department. It is a small building with three wings and a two-story dome (20 foot diameter). Its foundations are granite blocks; the building itself is brick. It is notable as the oldest scientific building on campus. Its construction and equipment costs were covered by a gift of $7,000 by Dr. George C. Shattuck, Dartmouth class of 1803, who stipulated that the Trustees match the gift with an additional $4,000. In 1955 the building was renovated and its original dome replaced, but otherwise the building remains substantially unaltered since its first construction.