After Hagop Pasha's appointment as the Ottoman Minister of Finance in 1887, he had Calouste prepare an oil survey of Mesopotamia. To develop the oil survey, Calouste merely read travel books and interviewed railroad engineers that were surveying and building the Baghdad Railway. Gulbenkian's oil survey led Hagop Pasha to believe that vast oil deposits lay in Mesopotamia (modern Syria and Iraq), to acquire tracts of land for the Sultan's oil reserves, and to establish the Ottoman oil industry in Mesopotamia.