 His services to geology were based on his attentive study of the volcanoes of the Andes and Mexico, which he observed and sketched, climbed, and measured with a variety of instruments.By climbing Chimborazo, he established an altitude record which became the basis for measurement of other volcanoes in the Andes and the Himalayas.As with other aspects of his investigations, he developed methods to show his synthesized results visually, using the graphic method of geologic-cross sections.