Brussels center

This route goes from the Yser metro station to the Louiza metro station. Along the way we come across

- In 2005, a sundial was installed in a new office building at Boudewijnlaan 12. A metal sphere suspended by a tension cable is used as a shadow caster. This is the largest vertical sundial in our country. In addition to vertical hour lines, horizontal date lines have also been installed. At the top, there is a line for astronomical winter and at the bottom, a line indicates the start of astronomical summer, and in between lies the date line for the spring and autumn equinox. At the request of architects Clernaux and Pinon, the sundial was adjusted to the geographical time difference. The hour digits at the bottom indicate summer time. Jan de Graeve designed the sundial and Willy Leenders calculated the hour and date pattern.

- On the De Brouckèreplein we find the 19th century Hotel Métropole. This hotel is associated with the Solvay congresses. These were prestigious meetings on physics and chemistry. The first was organised in 1911 by Ernest Solvay. This was also the first international meeting ever on physics. The first Solvay congress focusing on astronomy was held in 1958.

- In the St. Michael and St. Gudula Cathedral, you can see a brass line running on the black tiled floor, almost 34 meters long. This noon line can be used to determine when it is exactly noon.

The midday line was built in 1836 by Adolphe Quetelet and was part of a large project of the new Belgian government to eliminate the time differences in the different cities. This had become necessary because a train network was being built in Belgium and it was of great importance that the trains ran according to the same time indication. The midday line in the Brussels cathedral was the first to be built and Quetelet would later build 9 others and in total 41 midday lines were built in Belgium. Quetelet chose the church because of its ideal north-south orientation and because he thought it was important that the people would have access to this new time indication.

The noon line works thanks to a small opening or oculus in the thick stone central post of the stained glass window of the southern transept. When the sun is exactly in the south, the sun falls through the opening on the noon line in the church. The best period to observe the noon line is in the summer with a blue sky. Due to a high-rise building on the Sint-Gudulaplein, the sun is obstructed from mid-October to early March.

The noon line that can be admired in the church is not the original one that was created by Adolphe Quetelet and that was made of copper. Between 1982 and 1996, the church was restored and the floor was also re-laid. This caused the original noon line to disappear. However, thanks to the efforts of Paul Pâquet (then director of the Observatory) and the many gnomics enthusiasts, a new noon line made of brass was created and inaugurated in 2001, after new renovation works. The new noon line was created with the help of the research office of Walter Lavrauw who, together with André Koeckelenbergh, carried out the necessary measurements (now with modern instruments).

- We pass by the Koudenberg where we see a sundial on a building in neo-renaissance style with gothic features between the Palace of Fine Arts and the music museum 'Old England'. This is the former 'Pharmacie Delacre' from 1895. The building was designed by architect Paul Saintenoy. The mosaic of the sundial was made by the Italian Silvio Tolomei. The hour numerals are shown in Arabic characters.

- Just in front of the building of the Palace of the Academies stands a marble statue of Adolphe Quetelet. The palace itself is a neoclassical building from 1823-1828. Sculptor Charles-Auguste Fraikin was commissioned to make a statue in honour of Adolphe Quetelet who, in addition to being the founder of the Royal Observatory, was also secretary of the Royal Academy of Belgium (which he joined at the age of 24) and founder of the natural sciences of Society. The statue was inaugurated on 11 May 1880.

The International Astronomical Union (IAU) was also founded in this palace in the summer of 1919. This union would, among other things, realise the Carte du ciel project.

- After the walk you can take metro 2 or 6 at Troon back to the starting point of the walk.