In recognition of the importance of preservation efforts, this
periodic series features historic buildings on the UI campus. A
little more than a decade after it was built 100 years ago, the
UI Observatory became the site of a scientific development
considered revolutionary in its day. Joel Stebbins, a professor
at the UI, helped to develop a system to measure the brightness
of stars at the UI Observatory. He worked with an instructor,
F.C. Brown, to create a selenium cell to use in a photometer.
While it took time to perfect the selenium photometer, they used
their innovation to discover three double stars, construct a
light curve for the moon, determine the time of mid-eclipse
during the July 24, 1907, lunar eclipse and measure the
magnitude of Halley's Comet in May 1910. It was Stebbins who
convinced the UI Board of Trustees to establish an astronomy
department in 1905, just nine years after the observatory was
built. In the spring of 1895, the UI was given $15,000 by the
legislature - at the request of th