Book cover of Memories of a Heavenly City. [Photo provided to China Daily]

After studying at Princeton University and the University of California in Berkeley, Sidney Gamble visited China several times between 1917 and 1932 to conduct surveys that later resulted in his studies of Chinese society and culture. He used some photos in his academic publications and lectures, but the majority of the images was never exhibited in public.

Sidney Gamble worked as a research secretary for the Beijing YMCA, conducting social-economic surveys, helping establish community service programs and teaching sociology in China.

The negatives of his photos were found by his daughter, Catherine Curran, after his death in 1968. They were carefully placed in paper sheaths, annotated with captions and stored in rosewood boxes in the family's home in New York. They've been digitized and are in a Duke University library since 2006.

In 2008, Shen contacted Duke University as he was then writing a seminar paper on Sidney Gamble's Hangzhou photos. That led to the publication of the photo book in 2010.