The Planetarium of 1781

The Eisenga store and home, now simply labeled, "Planetarium."

The Eisenga store and home, now simply labeled, “Planetarium.”

Twelve miles into Friesland, we came to the town of Franeker, site of the world’s oldest working planetarium.  Eise Eisenga left school early, married and developed a wool carding business.  As a boy, he was a precocious mathematics student and, self-taught, he continued his interest in math and physics into adulthood.

In response to a unique planetary alignment in 1774 that certain religious types touted as forecasting the apocalypse, Eisenga designed and built a working planetarium in the ceiling of his living room with accurate, continuously-moving relationships between the sun and all known planets.  His living room, by the way, happened to be his bedroom, dining room and kitchen as well.  It took him until 1781.  No wonder he and his first wife only had one child!

The ceiling of Eisenga's living room--the planets trace accurate orbits around the sun

The ceiling of Eisenga’s living room–the planets trace accurate orbits around the sun

He designed and meticulously made the gear works, located in the attic above the living room ceiling, from wood disks and 10,000 steel nails that became the gear teeth.  The assemblage looks like the works of an over-scaled Swiss watch.  To those of us who still find astronomy and orbits an insolvable brain-teaser, how Eise could have pulled this off at the time of Thomas Jefferson is a confounding mystery!

Eisenga's gear works--in the 3' tall attic above the living quarters.

Eisenga’s gear works–in the 3′ tall attic above the living quarters.


When the Dutch king heard of Eisenga’s feat and visited remote Franeker to see the planetarium in the early 1800’s, Eisenga’s fame and future were assured, and in 2011, the Dutch government nominated the planetarium to be a UNESCO World Heritage site.

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