一大约是在清末的某一天,一位到兰州游历的外国人面对黄河水道上五辆一组庞大的水车群,摁下了照相机的快门。他把这幅照片做成了一帧明信片又寄回了他的国家。有意思的是,时隔一个世纪,有个叫王佳楠的中国人,又从国外的街边小摊上把它买了回来,并出版了一部《明信片清末中国》, One day, about one day in the late Qing dynasty, a foreigner who traveled to Lanzhou faced five large groups of water tankers on the Yellow River, and shut down the camera. He made the picture a postcard and sent it back to his country. What is interesting is that after a century, a Chinese named Wang Jia-nan bought it back from a street stall outside the country and published a postcard “Late Qing Dynasty China”