Electric car disturbances at the magnetic observatory of the United States Naval Observatory

Abstract

The magnetic instruments at the Naval Observatory in the city of Washington consist of a Kew vertical‐force needle, Kew declination needle, Kew horizontal‐force needle, and Mascart vertical‐force needle. These instruments are mounted underground, in a vault specially designed for the purpose, and are self‐registering by means of photography.The Observatory itself is situated on Georgetown Heights in the suburbs of the city of Washington, on a spot selected by a commission appointed for the purpose. The purchase of this site, which is irregular in shape, and contains nearly seventy acres, was made in 1882. One of the principal requirements of the commission was to choose a site which should probably remain free from disturbances due to the proximity of a city and the effects of traffic. The electric railway had not then been perfected, and no more desirable site could have been selected. The construction of the new buildings, laying out and grading the grounds, and preparing for the removal of the instruments extended over a period of ten years, and the old site of the Observatory on the bank of the Potomac was finally abandoned in 1893.