For two decades, Alvan Clark made a living as an artist, painting portraits from his studio near Boston. But his most lasting works -- and to many, his most artistic -- came later. Beginning in the 1840s, Clark built refracting telescopes -- glass lenses mounted in long tubes. Within a couple of decades, Clark and his sons were making telescopes for observatories around the world.
Today, many of their creations have vanished -- the victims of war, neglect, or simply changing times. Others are stored in vaults and basements, awaiting possible resurrection.
But many are still in use, including a few that still conduct scientific research. The U.S. Naval Observatory, for example, uses a 26-inch telescope to study binary stars. And Lick Observatory uses a 36-inch telescope for similar purposes.
But even the largest of the Clark telescopes are fairly small by modern standards. And refractors have some limitations that reflectors do not.
So several observatories have found new roles for their Clark telescopes -- as teaching tools, and as centerpieces for public programs. So students and the public can view the heavens through the 36-inch Lick telescope. They can also look through a 26-inch telescope at the Leander McCormick Observatory in Virginia, and a 16-incher at the Cincinnati Observatory. These telescopes preserve the work of a great artistic family: Alvan Clark & Sons.
We'll talk about the largest Clark telescope tomorrow.
Script by Damond Benningfield, Copyright 2011