The Bowring Treaty seems to have given little immediate stimulus to the volume of exports from Bangkok,but the period from the 1870s saw a fundamental change in both the composition and level of Siam's foreign trade.As a proportion of total exports,rice rose from 44 per cent in 1861-5 to 62 per cent by the mid-1870s, reaching over 70 per cent by the time of the world rice boom at the turn of the twentieth century. Other key export commodities in demand in world markets included teak and tin. Together, these three items comprised over 90 per cent of Siam's export by the early twentieth century. Bangkok was the destination of the great proportion of exported goods. In the newly liberalised economy,Bangkok played a key role and experienced considerable change in the process. Tpgether with new western mercantile establishments engaged in exporting and importing came investment in new wharves,warehouses,steam-driven rice mills and saw-milling businesses.