My paper examines in detail the mechanism of how Western railroad and mining technology arrived in China via foreign engineers from the late Qing into the Republican period. Empire offered German engineers trained in the leading European technical colleges the opportunity for lucrative careers overseas. The careers of these men spanned not only continents but also British, Dutch, and German colonial holdings, as well as paid service to the Qing / Chinese government. Two of these engineers, Gustav Behaghel and Friedrich Solger, also served as the first foreign faculty members in the Department of Geology at Peking University. Their contribution to the science of geology in China was based in fieldwork and their experiences as engineers in colonial mining ventures. The careers of these engineers transcended national boundaries and reflected the political and economic conditions in the late nineteenth and early twentieth centuries. Including engineers in the narrative of science transmission in China expands our understanding of science and of the scope of late Qing efforts to modernize. Not only capital flowed internationally, but also the men who built railroads and mined for the treasures of the earth.