Army officer, botanist, and geographer. Served in the Bengal engineers; lieutenant, 1841; major-general, 1871; lieutenant-general, 1875. Studied botany, physical geography, and geology in India. Carried out scientific expeditions in the Himalayas. Collected plants in Tibet, 1848. Consulting engineer in the railway department, 1858; secretary and head of the public works department, 1862. Member of the Council of India, 1875–89. President of the Royal Geographical Society, 1888–90. FRS 1854.