Found out a new word today – an orrery. With some time to ‘waste’ in Leeuwarden while we wait for the Drachsterbrug to re-open, Anne and I decided to take the train across to Franeker. Franeker is close to Harlingen and on the Van Harinxma canal between Harlingen and Leeuwarden. The main reason for going there though was the Eisa Eisinga Planetarium. Eisa Eisinga was actually a wool carder, but his father also taught him astronomy and Euclidian maths and he was clearly gifted as he published his first Maths book at the age of 15. He went on to build a planetarium in his bedroom! The orrery (a mechanical model of the solar system) shows the planets as they were in his day and is operated by a single pendulum turning a series of cogs in the attic. The planets turn in real time showing their relative positions across the sky. The system even shows the time the moon rises and sets each day, the star signs, the time and date and the relative position of the earth and the moon at any given time. It has apparently been running constantly for 235 years. The one thing he didn’t manage to model apparently is a leap year and so, every four years, they have to manually adjust the model by one day.
As well as the planetarium Franeker is lovely town and between 1585 and 1811 was a university town – a factor that helped Eise Eisinga significantly in his amateur astronomy. Franeker is also apparently the most important centre for the sport of Frisian Handball – a traditional Frisian sport that is like a cross between handball and fives. Players wear a hardened leather glove and hit a solid leather ball at each other!