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Dan Koehler (left), director of tours and special programs at Yerkes, chats
with the author about the history of the facility. In the background looms
the famous 40-inch refractor — the world’s largest lens-type telescope.
The telescope weighs 82 tons with a tube 64 feet long (19.5 meters).
The entire assembly rises above the basement level by 65 feet (19.8 m).
MICHAEL E. BAKICH
Astronomer Wayne Osborn explains some of the records of observations
made by American astronomer Edward Emerson Barnard during the time
he spent at Yerkes Observatory. MICHAEL E. BAKICH
Another of the telescopes at Yerkes with a high usage curve is the 24-inch
reflector. Groups use it, as well as the 40-inch refractor, most clear nights
of the year. COURTESY OF YERKES OBSERVATORY
Among the many historical settings at Yerkes is the office of Subrahmanyan
Chandrasekhar, who began working at the University of Chicago in 1937. It
is currently occupied by Jim Gee, the observatory’s director of operations.
DAVID J. EICHER
This blink comparator dates to 1905. Astronomers at Yerkes used it to
discover high proper motion stars, variable stars, and other changing
celestial phenomena. DAVID J. EICHER