Clark Telescopes 
If you wanted to buy a top-of-the-line telescope in the late 19th century, there was only one place to go: Alvan Clark & Sons of Cambridgeport, Massachusetts. The small family company made hundreds of refracting telescopes — the kind that use lenses to gather and focus starlight. The optics were second to none, providing especially sharp views of the heavens.
Many of those telescopes were made for university observatories, including the largest refracting telescope in the world, at the University of Chicago’s Yerkes Observatory. Its primary lens spanned 40 inches.
The Clarks stopped making telescopes almost a century ago. Yet many of their instruments are still in use today, including the 40-incher. Not many are still doing research, although they’ve found new life in education and public outreach. And they’re considered such treasures that they’re often celebrated with public events and commemorations.
Over the last year, for example, Albion College in Michigan has been celebrating the 130th anniversary of its Clark telescope — an eight-incher completed in 1884. It operated into the early 20th century, when it was abandoned for a while. It was returned to service a bit later, and was fully restored early in this century. Today, the telescope is prime teaching tool for Albion students — continuing the work it began 130 years ago.
We’ll talk about another Clark telescope tomorrow. And you can find out where you can see and even look through some Clark telescopes on our website at stardate.org/nightsky.
Script by Damond Benningfield, Copyright 2014