MADISON, Wis. (WMTV) - On this day- October 21, 1949- the Yerkes Observatory in Williams Bay officially opened.

The observatory housed the world’s largest refracting optical telescope at the time, along with laboratories, workshops and libraries.

The 40-inch telescope was first put on display at the 1893 Columbian Exposition in Chicago.

Two years later, construction on Yerkes Observatory began.

The Observatory was founded by astronomer George Ellery Hale, with funding from Chicago transportation tycoon Charles Tyson Yerkes.

Through history, famous astronomers have made stops in Williams Bay to see the stars, including Albert Einstein.

Today, Yerkes Observatory is considered the birthplace of modern astrophysics.

While the observatory title for world’s largest telescope was taken ove

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