The flight took place on April 26, 1873, and Polar Star reached an altitude of 4,600 metres (15,100 ft) before successfully landing near Paris.

[4] During the flight, the scientists conducted a series of meteorological and aeronautical experiments, for which Alphonse Penaud specially developed the instruments.

In this flight, for the first time, on the advice of physiologist Paul Bert, the scientists took small soft balloons with oxygen supplies.

This experiment allowed checking the aeronauts' behavior at altitudes with extreme atmospheric pressure and lack of oxygen in the air.

[7] This unusual way of breathing freely even where there was practically no oxygen allowed the scientists to conduct meteorological research and control the balloon.

[9] The flight on March 22, 1874, received widespread media coverage, making Joseph Crocé-Spinelli and Théodore Sivel famous in France and Europe.

[10] Joseph Crocé-Spinelli made his third flight on March 23-24, 1875, when the balloon Zénith flew from Paris to Arcachon over 22 hours and 40 minutes.

[11] The record of the Zenith was only broken eleven years later, in September 1886, when the Frenchman Henri Hervé made a 24-hour flight from France to England in the balloon Le National.

Gaston Tissandier later described the first hours of the flight: We are rising into the air, crossing Paris, where thousands of lights twinkle like the stars in the sky.

We slowly pass over the Tuileries Garden, the dome of the Invalides, and soon the spectacle of the great metropolis disappears from the horizon, giving way to no less grandiose rural landscapes... Tidying up the basket, methodically arranging the ballast bags, we begin to conduct our experiments.

Jobert throws printed leaflets overboard, intended to be collected by local residents on the ground and returned to Paris.

Gaston Tissandier described this event as follows: This crossing of the great river, performed at 10 am, with a view of the Cordouan Lighthouse, is undoubtedly one of the most touching moments of our journey.

In response to this sympathetic greeting, we wave our handkerchiefs...[12]After crossing the Gironde, Zenith flew another 6 hours along the ocean coast, and only around 5 pm did the aeronauts successfully land on a clearing in a pine forest near Arcachon.

[14] Inspired by the success of the record flight from Paris to Arcachon, Crocé-Spinelli, Sivel, and Gaston Tissandier immediately began preparing for a new expedition.

Sivel attached a thick mattress stuffed with straw to the basket's bottom to cushion the impact when the balloon landed.

Gaston Tissandier later recalled that at an altitude of 300 metres (980 ft), Théodore Sivel suddenly exclaimed with joy: Well, we are off, friends!

[15]At an altitude of 3,300 metres (10,800 ft), a large volume of hydrogen suddenly escaped from the "appendix" of the balloon, which was directly above the aeronauts' heads.

However, at an altitude of 5,300 metres (17,400 ft), the severely rarefied air had already taken its toll, and Tissandier, checking his friends' condition, recorded the following note in his notebook: Crocé - pulse 120 beats per minute, Sivel - 150 beats[15]Around 1 pm, Zenith reached an altitude of 7,000 metres (23,000 ft) and drifted over cirrus clouds, consisting of fine dispersed ice particles.

Joseph Crocé-Spinelli and Théodore Sivel died during the flight from asphyxia, while Gaston Tissandier miraculously survived but partially lost his hearing.

After the crash of Zenith near the town of Ciron (Indre), Gaston Tissandier, still in shock, realized that his friends had died during the flight.

To avoid undue curiosity from the crowd, Tissandier decided to move Crocé-Spinelli and Sivel's bodies to the nearest barn and locked them there.

In the morning, he wrote a long letter to the president of the French Society of Aerial Navigation Hervé Mangon and sent it to Paris.

The families of the deceased scientists were informed only 18 hours after the crash, and on April 16, the evening newspapers of Paris reported the sad news on their pages.

Practically all the major French newspapers immediately sent their reporters to the crash site, and by the morning of April 17, Gaston Tissandier was meeting them and his brother Albert at the local train station.

On April 18, the bodies of Crocé-Spinelli and Sivel were placed in metal coffins, loaded onto a cart, and taken to the local train station for transport to Paris.

[18] On April 19, a meeting of the French Academy of Sciences was held, at which its president Edmond Frémy gave a special speech.

[20] After the funeral of Crocé-Spinelli and Sivel, the French Society of Aerial Navigation and several major newspapers announced a public fundraising campaign to help the families of the deceased and to install a memorial at the crash site of the balloon.

This unique sculpture on the scientists' tomb attracts thousands of tourists who visit the Père Lachaise Cemetery every year.

[23][24] In 1983, the French politician and then Minister of Culture Jack Lang decided to design and build a large concert and exhibition hall outside of Paris.

Later, this name was registered as a trademark, and the concept of building large concert and exhibition halls called Le Zénith was expanded throughout France.