An old engraving showing a refracting telescope, Washington DC, USA It is from a Victorian mechanical engineering book of the 1880s. In 1870 the federal government gave the head of the United States Naval Observatory $50,000 to build it. Alvan Clark and his son, Alvan Graham Clark, built the Naval Observatory an achromatic refractor with a 26-inch (66-centimetre) lens doublet in 1873. It was located on a hill north of the Lincoln Memorial, along the Potomac River, in Washington, DC. This 40-foot-long telescope was the biggest refracting telescope in the world in its day.
An old engraving showing a refracting telescope, Washington DC, USA It is from a Victorian mechanical engineering book of the 1880s. In 1870 the federal government gave the head of the United States Naval Observatory $50,000 to build itself the best telescope it could. Alvan Clark and his son, Alvan Graham Clark, of Massachusetts built the Naval Observatory an achromatic refractor with a 26-inch (66-centimetre) lens doublet in 1873. It was located on a hill north of the Lincoln Memorial, along the Potomac River, in Washington, DC. This 40-foot-long telescope was the biggest refracting telescope in the world in its day. The observatory was eventually moved to a new location with a new dome. It is still used today, mainly for observing double stars and planetary satellites.
Size: 2807px × 4252px
Location: Washington DC, USA
Photo credit: © M&N / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1800s, 40, 1873, 19th, achromatic, alvan, american, astronomy, black, century, clark, dc, design, device, dome, early, engineering, engraving, f00t, glass, historical, history, hundreds, illustration, industrial, industry, machinery, magnifying, mechanical, naval, night, nineteenth, observation, observatory, observe, planetarium, refracting, refractor, revolution, sky, stars, telescope, usa, victorian, view, viewing, washington, watch, white
