It was to be nearly 50 years later that Sir Charles Trevelyan, Governor of Madras, instructed Col. Douglas Hamilton to explore the hill country in the western part of the Madras Presidency, requesting special advice on the feasibility of establishing sanatoria for the British in the South and of developing revenue- earning projects without endangering the environment, as had happened in Ceylon where coffee had destroyed not only the rain forest but also paddy cultivation in the north-central rice bowl of ancient Ceylon. Hamilton climbed throughout the Ghats in Munnar region. 15 years later, John Daniel Munro noted that much of Munnar's land was suitable for coffee plantations. Munro, Henry Turn and his half-brother AW Turner obtained ownership of the Cardamom Hills from the Raja of Travancore and began clearing forest around Devikulam in 1879. Soon many other Europeans began establishing tea plantations in the area throughout the 1880s. Early plantations had few facilities and were mainly huts of straw. Most labourers on the tea estates were Dalits from present-day Tamil Nadu.