Yuan Yi’s talk examines the mechanization of cotton spinning in turn-of-the-twentieth-century China with emphasis on the Sino-American exchange of spinning technologies, cotton varieties, and technical experts. Drawing upon a variety of technical writings such as machine manuals, engineering journals, factory regulations, and correspondence between American machine firms and Chinese cotton mills, it discusses how the Chinese strove to solve technological problems through continued modification and maintenance of foreign machines that failed to process short-staple Chinese cotton. By reconstructing the specific jobs performed by engineers, machinists, and female machine operators on the Chinese shop floor, she argues that what enabled mechanization was their multiple layers of knowledge, rather than the machines per se, obtained through hands-on experience of machines as well as formal engineering education. New sets of knowledge were generated in this process, and some of them traveled back to the headquarters of machine builders, culminating in customized machines and updated manuals. In an era of imperialism, she contends, the Chinese workers were not passive recipients of Western machinery and knowledge but active participants in global technology transfer.