The Royal Eise Eisinga Planetarium is an 18th-century orrery in Franeker. It is currently a museum and open to the public. The orrery has been on the top 100 Dutch heritage sites list since 1990 and nominated as a UNESCO World Heritage Site candidate based on its long history as a working planetarium open to the public and its continued efforts to preserve its heritage.
The orrery was built from 1774 to 1781 by Eise Eisinga. An orrery is a planetarium, a working model of the solar system. The 'face' of the model looks down from the ceiling of what used to be his living room, with most of the mechanical works in the space above the ceiling. It is driven by a pendulum clock, which has 9 weights or ponds. The planets move around the model in real time, automatically. The planetarium includes a display for the current time and date. The plank that has the year numbers written on it has to be replaced every 22 years.
The Eise Eisinga Planetarium is the oldest still working planetarium in the world. To create the gears for the model, 10,000 handmade nails were used. In addition to the basic orrery, there are displays of the phase of the moon and other astronomical phenomena. The orrery was constructed to a scale of 1:1,000,000,000,000 (1 millimetre: 1 million kilometres).References:
The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.