Signedon case's face: "B Martin London
FunctionThe planetarium, a simpler kind of orrery, was designed as a representation of the solar system. Usually unmechanized, it showed the relative motion of the planets around the sun. It was a pedagogical tool, not a research instrument. The lunarium and tellurian attachments helped an instructor to explain why the seasons and the phases of the Moon occur, as well as more complex concepts such as why the eclipses of the satellites of Jupiter were used to find longitude on land and to determine the finite velocity of light. At the time that this example was made, Saturn was still the most distant planet known.
Historical AttributesAfter the 1764 fire of Harvard Hall, the College took steps to replace the lost orrery that had been given in 1732 by Thomas Hollis, nephew and heir of the man who established the Hollis professorships and who had donated much of Harvard's early apparatus. When the ship John and Sukey left London in late August 1766, on board, destined to Harvard's new apparatus chamber, was this instrument, described in the bill of lading as "a Planetarium with wheel work mounted on a Brass Pillar," and valued at £9.9.0. The bill of lading also inventoried the lunarium and tellurian, which cost £3.13.6 and £2.12.6 respectively.
Published ReferencesDavid P. Wheatland, The Apparatus of Science at Harvard, 1765-1800 (Cambridge: Harvard University Press, 1968), 49-51.