Meridian

[]The Leiden prime meridian is a line going from north to south through the exact spot of where the meridian telescope once stood. While this meridian is not as special as the Greenwich prime meridian, it served exactly the same function, namely time measurement.

With a meridian telescope one can only look across the meridian of that telescope, this makes sure that the observations are always very precise, as only one axis has to be managed. Any star that crosses the meridian does so in a very precise manner, namely every 23 hours and 57 minutes. This makes stars very accurate clocks and meridian telescopes very accurate measuring devices. And this is exactly what we have done with this device. From 1861 to 1911? the Dutch time was measured in Leiden. This time was called the New Amsterdam time and was officially based off of the meridian of the Westertower in Amsterdam. Besides that we also measured the time for the three big harbors of the Netherlands. Den Helder, Hellevoetssluis and Vlissingen.

We sold this time and made significant profit from the time service, although astronomers had differing opinions about its importance. Some were happy to do it, while others saw it as a waste of time. Either Way the service stopped in 1911 when Paris Observatory started to transmit the time via radio using the Eiffel tower as an antenna.

In 1884 the prime meridian conference was held and there it was decided that the Greenwich meridian would be the official prime meridian of the world. The Amsterdam (and this the Leiden) meridian was a competitor in this race, but we dropped the idea very quickly after seeing the verocity of the UK and France.

Currently there are plans to mark the Leiden meridia, just like the Greenwich one. []