In the spring of 1934,Mr.T.F.Hou and the writer were instructed bythe Geological Survey of China to explore the provinces of Kansu~1 and Ninghsiawith a view to
1. Combeau, De la houille ses productions dans le monde entier, son emploi ses particularites 1921. $ 3.70
1. Combeau, De la houille ses productions dans le m