When the Buhl Planetarium opened in 1939, it was the fifth major planetarium in the United States and helped pave the way for people to celebrate the sciences.

Photo: The Buhl Plantarium circa 1939, the year it first opened in Pittsburgh’s Northside. Courtesy of Carnegie Science Center

By Haley McMonagle

The Foucault Pendulum was one of the highlights of the Buhl Planetarium when it first opened in 1939 in Pittsburgh’s Northside.

Invented by the French physicist Jean-Bernard-Léon Foucault in 1851, the pendulum was originally built to demonstrate that the earth rotates on an axis. The pendulum is a large mass, usually a sphere, suspended from a long line. The way it is mounted allows the mass to swing in any direction; the way it rotates shows how it relates to the surface of the earth. The pendulum also shows the true cardinal points of the compass. The Foucault Pendulum was one of the Buhl Planetarium’s original “talking exhibits.” There was an audio room a short distance away from the brass and marble “pendulum pit,” and with the push of a button, turntables would activate in the room and play a special record explaining the exhibit. This was considered state-of-the-art in its time.

When the Buhl Planetarium opened on Tuesday, Oct. 24, 1939, it was the fifth major planetarium in the United States, joining ones like those in Chicago, New York, Los Angeles, and Philadelphia. The growth of planetariums in the U.S. at this time shows the expansive impact of astronomy in the late 1930s. Astronomy is a scientific field that interacts with society directly. Copernicus, as early as the 1500s, claimed that the earth was not the center of the universe. Hans Lippershey, a German-Dutch lensmaker, is often credited with inventing the first telescope in 1608. A year later, Italian astronomer, Galileo Galilei created an improved version, which could magnify objects 20 times. Humans, often captivated by space, look to astronomy to answer questions about our planet like “How old is it?” and “What will become of it?” The American astronomer Carl Sagan describes how astronomy contributes to society in his book, “The Pale Blue Dot.”

“It has been said that astronomy is a humbling and character-building experience,” writes Sagan. “There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”

The Buhl Foundation, which was created after the death of Henry Buhl, Jr. in 1927, funded the building of the Buhl Planetarium. The foundation funds four specific types of programs with a focus on those in Allegheny County and the city of Pittsburgh; education, youth development, human services, and economic and community development. The primary focus has always been sustaining the vitality of the communities they support. While a lot of cities had natural history museums in the early 1900s, few had an emphasis on physical science as the Buhl Planetarium did: It pioneered what would later be known as a “science museum” or “science center.”

Dewitt Peart worked at the Buhl Planetarium for a year after graduating from high school in 1950.

Dewitt Peart, right, explains how the Foucault Pendulum works to a tour group of Cub Scouts. Peart worked as an aide at Buhl Planetarium. Courtesy of Friends of the Zeiss

“I was an aide, some referred to as a docent, but we went by the term aide,” said Peart. “You had a coat to wear. You were identifiable to the public and you would demonstrate different exhibits… Navy blue jackets with a shirt and a tie and lady aides had a white blouse and skirts, I think. Quite a few female aides at the time, maybe six, eight, or 10.”

According to Peart, the job involved being self-motivated. Other than their allotted lecture times in the afternoon and evening, he said, the aides would either go from exhibit to exhibit to demonstrate to the groups they saw passing through or form their own groups.

The newly built planetarium housed the “Theater of the Stars,” which seated 492 visitors and featured a massive 65-foot diameter dome as its centerpiece. Images of the night sky were cast onto the dome through a Zeiss Model II projector, and in 1940, 200,000 guests visited the planetarium and witnessed the projector’s capabilities.This projector was one of the last of its kind, produced in 1938 at Zeiss Optical Works in Jena, Germany before World War II, when the factory that built it began manufacturing bombsights for German aircraft.

Peart described how the aides learned about the exhibits featured at the Buhl Planetarium:

“They had a manual. You had to be prepared enough that you would answer questions from an audience. You didn’t have the book with you, so you had to wing it,” he said. “I mean, I just kind of took to it, which was amazing because I was the shyest boy in the world. I didn’t like to make eye contact on the streetcar, that’s just the way it was. Whatever drew me there, I have no idea.”

But the draw was clear: It was Peart’s love of astronomy, which began at a young age. He joined the Amateur Astronomers Association of Pittsburgh (AAAP) as a child; the group would periodically visit the Buhl Planetarium. When he applied to work at the planetarium, the staff already knew who he was.

The planetarium had an immense amount of historical equipment and artifacts. A large world map originally created by the U.S. Maritime Commission for the 1939 World’s Fair in New York City was on display in its Grand Hall. Works of art were on view, like a U.S. Steel mural that depicted the rise of technology and a painting of Halley’s Comet from Great Britain. Rooms included a beautiful wood-paneled library, lighted picture displays, and a rainbow wallpaper walkway that refracted light. Aides guided guests through these exhibits of equipment and artifacts.

“[The aides] were all college students actually,” said Peart. “I was out of high school, so I was the youngest one there. The other ones would have been freshmen, sophomores, juniors, or seniors in college. They worked there part-time. You would have to learn the exhibits and demonstrate them. It was very informal, you could have, depending on the exhibit, something like the electric coil which would give off sparks. You might demonstrate that or give a lecture up to 25 minutes on biology… with an audience of five to 10 to 200, depending on the time of day.” Peart went on to work at the Allegheny Observatory for 45 years.

The Buhl Planetarium also featured the Astronomical Observatory, which was housed on the third floor. Completed in 1941, its focus was on general public observation rather than astronomy research. It was originally known as “The People’s Observatory,” but that name eventually died out with the rise of Communist “People’s Republics” following World War II. The Astronomical Observatory was dedicated on Nov. 19, 1941, with an address given by Harlow Shapley, a renowned astronomer of the 20th century and then Director of the Harvard College Observatory. A Siderostat-type refractor telescope inside the Observatory allowed visitors to view the stars and planets. “First light,” or first use of this telescope, was a view of Saturn. Siderostat-type refractor telescopes use a mirror to project views of the night sky to members of the audience while they are comfortably in their seats. When typical research telescopes, on the other hand, were adjusted, the viewers would have to move along with it to observe the sights it captured.

Buhl Planetarium, circa 1962. It functioned in what is now known as Allegheny Commons from the 1940s to the 1980s, before plans were discussed to move it to the North Shore. Courtesy of the Carnegie Science Center

The Buhl Planetarium functioned from the 1940s to the 1980s. Then in 1982, it became the Buhl Science Center, with plans to relocate to the North Shore. Glenn A. Walsh worked at the Buhl Science Center from 1982 until 1991. He was a planetarium lecturer and guided guests on tours of the exhibits.

“I had been visiting [the] Buhl Planetarium since I was a child,” said Walsh. “So when I got out of college, [the] Buhl Planetarium is one of the places I applied to for a job.”

He primarily enjoyed his work with astronomy. At that time, the Siderostat-type telescope was still in use there.

“I have been studying astronomy for years,” said Walsh. “But mainly the training I need to use the telescope, I got on-site.”

The Buhl Science Center merged with Carnegie Museums of Pittsburgh and in October of 1991, 52 years since the opening of the Buhl Planetarium, The Henry Buhl, Jr. Planetarium & Observatory opened in what is now the Carnegie Science Center.

“The big changes came when it transitioned to the Carnegie Science Center,” said Walsh.
The building that was the Buhl Planterium’s home for so many years now remains as part of the Children’s Museum of Pittsburgh. The Children’s Museum moved into their first home, the old Allegheny Post Office, in 1983. After the Buhl Planetarium was vacated, the Children’s Museum took on the space right next door and the two buildings were joined together.

While there have been many changes, the Children’s Museum has kept some of the old exhibits, such as the Buhl Planetarium’s historic Foucault Pendulum. Reinstalled in 2005 with an extra structure added to the roof of the building in its original spot to support its 150-pound weight, it wowed a whole new generation. People believed they were witnessing the pendulum shift on its own, but in fact they were seeing the earth move. Guests can view the pendulum free of charge anytime the Children’s Museum is open. It is located in what the Buhl Planetarium referred to as the first floor Grand Hall but what now functions as a cafe.

Though the city of Pittsburgh and the world itself have modernized, there is no doubt that the Buhl Planetarium paved the way for how people celebrate the sciences. The Carnegie Science Center sets out to welcome everyone into a community of lifelong learners who dare to ask questions; the Children’s Museum of Pittsburgh still manages to capture peoples’ sense of wonder, regardless of age. It was the Buhl Planetarium, though, that began to show an audience who had never before experienced science and astronomy an accessible form of learning that inspired generations.