This showcase is dedicated to the slightly less relevant object in our collection.

This is a board full of plugs which connected the clocks in various places of the old observatory with the mother clock. In this time, clock mechanics were too large to fit in the back of clocks and had to be sent around with cables.

At first glance, this clock may not seem anything out of the ordinary. However instead of the regular 12 hours, this clock goes up to 24. Astronomers use this 24-hour clock to keep track of startime. This is unrelated to our normal time, so looking outside won’t tell you if it is morning or evening in startime. The 24 hour display has become common in digital clocks, but it never caught on in analog ones.

Meteorites Left: This is a part of a meteorite that comes from the asteroid belt, an area between Mars and Jupiter that is occupied by a lot of asteroids. Middle: This is a piece of moonrock and comes from an asteroid that was originally part of the Moon (NWA4881). Right: This piece of meteorite comes from Mars. It is part of the Tissint meteorite that landed in Morocco in 2011. (Property of Alex)

Plague epidemic in Leiden Just like in most places in Europe, there have been numerous outbreaks of the plague in Leiden throughout the Middle Ages. The outbreaks in the 17th century were especially deadly; between 1624 and 1625 almost 10,000 people died - twenty percent of the population at the time. A graveyard for the poor was opened just outside the city walls, where the observatory is currently located. Many of the plague victims were buried here. It was closed again in 1816. During the renovation in 2009 many bones emerged, like the bones that are displayed here.