His early interest in botanical studies and glaciers soon led Saussure to undertake other journeys across the Alps. In 1767, he completed his first tour of Mont-Blanc, a trip that did much to reveal the topography of the snowy portions of the Alps of Savoy. He also carried out experiments on heat and cold, on the weight of the atmosphere and on electricity and magnetism. For this, he devised what became one of the first electrometers. Other trips led him to Italy, where he studied Mt. Etna and other volcanoes (1772-73), and to the extinct volcanoes of the Auvergne, in France.