LA BOULE

Somewhere between history and science, this venue opens its doors exclusively to visitors: how did the electron beam make it possible to observe the infinitely small? Why does this architecture seem straight out of the best science fiction novels?

In Rangueil, this tour features two speakers: a guide and a researcher from the CEMES laboratory (Centre for Materials Development and Structural Studies). Their commentary offers an insight into the impressive scientific heritage of the 1950s...

Toulouse was then at a crossroads in its history: it was both a rural town AND a hub for researchers in the post-war race for scientific discovery! A hub for aeronautics and physics, it attracted an ever-increasing number of students, who would soon see campuses springing up alongside the fields and meadows. Indeed, it was Charles de Gaulle who inaugurated the Laboratory of Electronic Optics here in 1959 – now known as CEMES.

In practical terms, it was Gaston Dupouy who designed the most efficient of microscopes there. He created an electron gun capable of reaching 95 per cent of the speed of light. Its beam enabled him to magnify images a million times over to observe bacteria: a remarkable feat!

To achieve such high voltage (1.5 million volts), the microscope’s column (which has since been dismantled) was powered by a Cockcroft–Walton-type accelerator. Back then, the instruments were monumental in size: this was ‘Big Science’! This is where your eyes will pop: the ‘Boule’, a 26-metre-diameter structure designed by architect Camille Montagné, still houses this accelerator. It consists of tubes topped with 9-metre-high polished steel ‘mushrooms’, but shhh… you have to see it to believe it…