Conditions in China ensured there was a ready supply of cheap labour.The southern provinces were overpopulated and subject to invasions, rebellions, severe floods and famines between 1849 and 1887.

• 从1849到1887，中国南部省份的人口过剩、连年受到侵略、百姓造反以及严重的水灾与饥荒使中国能够大量提供廉价劳工。