From 1908 to 1968, an American sociologists and economist named Sidney David Gamble came to China and devoted himself to research of Chinese rural socio-economic problems. During his four visits to China, Gamble took over 5,000 black and white pictures, colored slides, and 39 rolls of filmstrips.
In 1917, Gamble and his group came to Sichuan for research and took over 500 precious photos of Santai, a county in Sichuan. Some of these photos were published once in black and white. This is the first time they came in colors. They recorded the change of Sichuan over a century.