 Complete the following phrase:  Timber trade with Afghanistan had begun in the 19th century. Since the Mehtar enjoyed de facto rights over all forests of Chitral, the revenue generated accrued to the treasury. During the reign of Aman ul-Mulk the trade was at its flourishing best and sometimes earned the state up to 40,000 Kabulis annually. Aware of the value of timber, Shuja ul-Mulk established a Forestry Department in 1908. The department regulated not only the timber trade but also introduced measures to control the use of timber locally, including the imposition of a tax on firewood. Trade in timber continued under Shuja ul-Mulk. However it came to a complete halt following the 