https://archive.org/details/researchinchina01walcgoog/page/n175
(I don't think it's out of copyright everywhere in the world, actually. It is in the US, just like anything published before 1923; it is, also, in any country applying the 'rule of the shorter term' (that includes most of the EU), because it is out of copyright in the country where it was originally published. But the main author of this volume (the US geologist
Eliot Blackwelder) died in 1969, i.e., 'only' 49 year ago, thus the work should still be copyrighted in countries that do not apply the 'rule of shorter term' and have copyright extending to 50 years
post mortem auctoris or more.)