5241 Broad Branch Rd NW
Washington, DC 20015, USA

Carnegie Institution of Washington, Department of Terrestrial Magnetism, Standardizing Magnetic Observatory, 5241 Broad Branch Dr NorthweSt Washington, District of Columbia, DC

The Carnegie Institution of Washington, with funds provided by industrialist and philanthropist Andrew Carnegie, established the Department of Terrestrial Magnetism 9 DTM) in 1904 to survey and measure the earth`s magnetic fields. The Standardizing Magnetic Observatory (SMO) building, used for testing measuring instruments (galvanometers, earth inductors, and magnetometers, for example), was designed by the well-known Washington, DC, architect Waddy Wood who also designed the DTM`s adjacent headquarters and laboratory building.

Carnegie Institution of Washington, Department of Terrestrial Magnetism, Brass Foundry, 5241 Broad Branch Dr NorthweSt Washington, District of Columbia, DC

This building originally served as a foundry to cast nonferrous materials for tools, measuring instruments, and various fasteners and fittings used in magnetic observations undertaken the Carnegie Institution of Washington`s Department of Terrestrial Magnetism.

Carnegie Institution of Washington, Department of Terrestrial Magnetism, Atomic Physics Observatory, 5241 Broad Branch Dr NorthweSt Washington, District of Columbia, DC

The Atomic Physics Observatory (APO) was completed in 1938 to improve the capability of measuring the earth`s magnetic fields which was undertaken by the Carnegie Institution of Washington`s Department of Terrestrial Magnetism, beginning in the early 1900s. The APO contained an electrostatic generator and tube that operated at electrical potentials of more than five million volts.