The first train on European territory ran from Brussels to Mechelen. Frontrunners for the expansion of the rail network We were frontrunners in Belgium for the expansion of the rail network. But the train passengers soon encountered a problem: time. Until that first train, the time indication could differ from city to city. That difference could be up to 25 minutes. How could the travelers catch the train on time? At what time occur for this? But also: what about the risk of collisions? The solution came from the well-known statistician Adolphe Quetelet.

Before the scientist came up with an idea for uniform timekeeping, clocks were set using sundials. Because not every city is on the same longitude, the sun does not reach its highest position at the same time everywhere. This difference in time only became a problem with the expansion of the rail network.

The Belgian government commissioned Quetelet in 1836 to find a solution for this. The Brussels scientist – of Ghent origin – had already proven his skills in various areas. He was director of the Royal Observatory and thanks to him Belgium was one of the first countries in the world with very accurate temperature measurements. His research pioneered later weather forecasts. He was also a scientist who placed great importance on the social influence of his inventions. So this assignment was a perfect fit for zoom.

He came up with the idea of ​​using the technique of a meridian line: a line that runs exactly from the north to the south. The sunlight, radiating in from an opening, crosses that line at the moment of ‘true noon’, at twelve o’clock solar time: the moment of time to sunrise and the time to sunset, are of equal length. The moment that the beam crosses the line takes only six seconds.

Quetelet ordered the placement of 41 meridian lines across the country. The locations do have some conditions for this. The building had to be well oriented. Furthermore, the space had to be long enough, because of the position of the sun in winter and in summer. The beam during true noon therefore does not fall in the same place on the line for a whole year. He also wanted the meridian line to be visible to everyone so that the general public could access the correct timestamp. Because of those criteria, the first locations he chose were often cathedral churches. Later he also placed meridian lines in squares, because he horizontal that a church usually closed at noon. In a square he worked with the shadow of a sphere, which came to stand on the meridian line right at noon.

Brussels time

He drew the first meridian line in the cathedral of St. Michael and St. Gudula. That line became the prime meridian. Quetelet calculated how much longitude the meridian lines in other cities deviated from those in Brussels. For example, he was able to calculate using a table how much the true afternoon differed from Brussels in those places. The time during the rest of the country was adjusted to the measurement in Brussels: our national time was therefore Brussels.

Unfortunately for Quetelet – who put a lot of influence on the development of this project – the time measurements with meridian lines were quickly outdated. A few years later – in 1840 – Brussels time was transmitted directly from Brussels via telegraph. Only 11 of the 41 planned meridian lines have actually been constructed.

Some of those meridian lines can still be admired today. For example in the Cathedral of Our Lady in Antwerp from the Grote Markt in Bruges. And the prime meridian, which is still shining in the cathedral of Saint Michael and Saint Gudula in Brussels

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