W.M. Keck Foundation Central Rotunda

At the nexus of the original building, the restored W. M. Keck Foundation Central Rotunda celebrates the intersection of science and mythology, earth and sky, and the man whose vision brought the Observatory into being.

Foucault Pendulum

The gently swaying Foucault Pendulum in the W.M. Keck Foundation Central Rotunda has long been a visitor favorite since the building opened in 1935. One of the largest such devices in the world, the fully restored pendulum is actually an elegant scientific instrument which demonstrates the Earth's rotation.

The 240-pound brass ball, suspended by a cable 40 feet long, swings in a constant direction while the Earth turns beneath it. The pendulum is mounted to a bearing in the rotunda ceiling that does not turn with the building as it rotates with the Earth. A ring magnet at the bearing gives a little tug on each swing of the pendulum to keep the pendulum in motion. As the day passes, the pendulum knocks over pegs set up in the pendulum pit and indicates the progress of rotation.


Hugo Ballin Murals

On the vaulted ceiling and upper walls of the W. M. Keck Foundation Central Rotunda are Griffith Observatory's greatest artistic treasure: the Hugo Ballin Murals. Workers have carefully and completely restored the murals so that they appear as they did when first painted by muralist, film producer, and author Hugo Ballin (1879-1956) in 1934-35.

Medieval cathedrals told stories in stone. The Ballin ceiling mural celebrates classical celestial mythology, with images of Atlas, the four winds, the planets as gods, and the twelve constellations of the zodiac. The eight rectangular Ballin wall murals depict the "Advancement of Science" with panels on astronomy, aeronautics, navigation, civil engineering, metallurgy and electricity, time, geology and biology, and mathematics and physics.

In addition to Griffith Observatory, Hugo Ballin's murals also appear throughout Los Angeles in such noted buildings as the Wilshire Boulevard Temple, the Los Angeles Times Building, and Los Angeles City Hall Council Chambers.


Griffith J. Griffith Exhibit

Griffith Observatory is the product of one man's singular vision for public astronomy: Griffith J. Griffith (1850-1919). A new exhibit celebrating his contributions to Los Angeles resides in the former ticket alcove in the W.M. Keck Foundation Central Rotunda. The exhibit features the signed 1896 Los Angeles City Council resolution accepting Griffith's donation of the land for Griffith Park as well as the official portrait of Griffith. This was painted after his death and so includes the completed Observatory over his shoulder.

Anchoring the exhibit are the words Griffith was reported to have uttered after looking through the largest telescope in the world at Mount Wilson Observatory: "Man's sense of values ought to be revised. If all mankind could look through that telescope, it would change the world." Griffith envisioned a major public observatory in Griffith Park where the people of Los Angeles could be transformed by experiencing the marvels of the night sky. Though he did not live to see the Observatory built, Griffith's will ensured that his vision was realized. The building opened May 14, 1935, and has become a beloved icon of the city Griffith loved.

The W. M. Keck Foundation Central Rotunda also includes an information desk, a ticket window, and nearby bathrooms.