Zenith balloon ascent. Coloured historical artwork of the 1875 Zenith flight. Journalist Joseph Eustache Croce-Spinelli (1845-1875), naval officer Henri Theodore Sivel (1834-1875), and French author and scientist Gaston Tissandier (1843-1899) are seen in the basket of the balloon Zenith after losing consciousness due to lack of oxygen. They reached an altitude of 8,600 metres (28,000 feet) near Paris, France, on 15th April 1875. Croce- Spinelli and Sivel never regained consciousness and died during this ascent. Tissandier survived, but the ordeal left him deaf. This illustration was published in The Atmosphere by Camille Flammarion, in 1873.