Long live the Qing!

In 1793, the British emissary Lord Macartney arrives in Beijing, presenting Britain's newest technological achievements. Macartney himself should achieve a trading agreement with China- and he convinced the Chinese. Unlike OTL's emperor Qianlong, the Son of Heaven agreed, but also demanded the British to support China with the most modern technologies, for the emperor was not yet corrupted by Heshan and lacked imperial arrogance. The trade relations between Britain and China improved (though China was rather interested in technology than commerce ), and Chinese scholars should travel abroad and study the ways of the West, despite the protests of the old Confucian gentry. On the other hand, the spreading of Christianity was prohibited. By the 6th year of Jiajing (Qianlong's successor), most of these scholars returned- indeed, their mission was a success. The Chinese still regarded the British as an inferior, barbaric race but their technological advance was held in high esteem. Army and navy were thoroughly reformed and (given that corruption would have been not that widespread) the administration's efficiency increased. Further delegations were sent to the West, especially after the Napoleonic Wars. Now other countries than Britain were interested in the Chinese market, and the technological transfer went on. By the late 1820s the Chinese government exploited Manchuria's hills, rich in iron ore and coal. A railroad network was introduced, and the army further modernised (due to China's exports, there were enough funds to do so), but the old division in Eight Banners and Green Standard Army remained. Ironclads, heavy artillery, etc. were now no longer imported but produced by China herself, while military experts from Britain, France and the German states were invited to improve the army's military strength. Although China's economic policy was very tolerant (compared to OTL), the British income was still too low. China was still the world's most prosperous Empire and endowed with a considerable miliraey power.