This map of Eastern Turkestan can be found in appendix to Through Jade Gate and Central Asia: an account of journeys in Kansu, Turkestan and the Gobi Desert (1927) written by the British missionaries Mildred Cable, Francesca French and Evangeline French. Upon orders from His Majesty’s Service, the missionaries leave their long-term post in the Shansi province in China where they have worked for 21 years to return home to England. This map is a complementary document to their journey through Central Asia.
This map illustrates the main trade route as well as the route followed by the authors, across the Gobi Desert from the Kansu region located north of Tibet and marked to the southeast of the map, stretching northwest through Mongolia and Sinkiang. Most geographical information is concentrated along this strip, marking cities such as Kanchow, Suchow, Hami and Urumchi, as well as smaller towns and villages along the route. Rivers and lakes are noted and parts of the Great Wall of China are illustrated to the southeast of the map.
Note that this is the same map as “Map of Sinkiang (Chinese Turkestan) marking each oasis on the main trade route across the Gobi Desert” from the book A Desert Journal: Letters from Central Asia (1934) written by the same authors. However, the travel routes followed by the authors differ in the two maps.