Mont Blanc massif led to calls to limit access to the most popular summits and for the mountains to be treated with greater respect. The Mont Blanc massif has provided numerous opportunities for academic research, dating back to the very first ascent of Mont Blanc in 1786 during which Michel Paccard carried scientific equipment to confirm it as the highest summit. In 1820, an ill-fated expedition led by Dr Hamel included pigeons intended for release at varying altitudes to measure the impact of reduced air density on their ability to fly. In 1890, Joseph Vallot built a small meteorological observatory at approximately between
1996 Mount Everest disaster supplemental oxygen, guide Boukreev from the Mountain Madness team reached the summit (8,848 m/29,029 ft) first at 13:07. Many of the climbers had not yet reached the summit by 14:00, the last safe time to turn around to reach Camp IV before nightfall. Boukreev began his descent to Camp IV at 14:30, having spent nearly 1.5 hours at or near the summit helping others complete their climb. By that time, Hall, Krakauer, Harris, Beidleman, Namba and Mountain Madness clients Martin Adams and Klev Schoening had reached the summit, and the remaining four Mountain Madness clients had arrived. After this time,