[1] Teisserenc de Bort pioneered the use of unmanned instrumented balloons and was the first to identify the region in the atmosphere around 8-17 kilometers of height where the lapse rate reaches zero, known today as the tropopause.

In 1883, 1885 and 1887 he made journeys to North Africa to study geology and terrestrial magnetism, and during this period published some important charts of the distribution of pressure at a height of 4,000 metres.

[2][3] In 1898, Teisserenc de Bort published an important paper in Comptes Rendus detailing his researches by means of balloons into the constitution of the atmosphere.

That is why Teisserenc de Bort carried out 200+ more balloon experiments (with a substantial part of them being held during the night to eliminate radiative heating) until 1902, when he suggested that the atmosphere was divided into two layers.

He also carried out investigations near Viborg in Denmark 1902-1903,[4] in Sweden and over the Zuider Zee, the Mediterranean and the tropical region of the Atlantic, and fitted out a special vessel in order to study the currents above the trade winds.