The Sidney D. Gamble Photographs collection at Duke University Libraries provides a wealth of historical images. Gamble travelled in China several times and also took photos in Japan, Korea, and Russia. Currently available on this site are his images from 1917-1932. One can browse the collection by place and subject. Since the bulk of the images are from China, there is an interactive map that shows where and when he photographed. The images are available in a medium size that is appropriate for PowerPoint and a larger size that could be used to make details for teaching.