The 40-inch refracting telescope at Yerkes Observatory in Williams Bay, Wisconsin, contains the world’s largest refracting lenses. Built in 1895, the telescope contains two lenses, one made of crown glass, and one made of flint glass. The lenses are each 40 inches in diameter, weigh 500 pounds, and have a 62-foot focal length. The telescope and observatory…
science
OBJECT HISTORY: X-Ray Shoe Fitting Machine
Intended to help customers get the perfect pair of shoes, X-Ray shoe fitting machines like this one from Sturgeon Bay were popular in the 1930s, 1940s and 1950s.
OBJECT HISTORY: Employers Mutual Audiometer
This Maico Audiometer was one of many devices used by health and safety consultants of the Employers Mutual Liability Insurance Company of Wisconsin throughout the mid-to-late 1960s. Employers Mutual was the very first workers compensation insurance company in the United States. The company was founded in Wausau, Wisconsin, in 1911 shortly after the nation’s first workers compensation law was…