I see that I Married Adventure is still in print, even though it was first published in 1940.
I have a 1940 edition, and the 1941 (first printing) of Four Years in Paradise; they had belonged to my father and apparently were purchased right when they first came out.
One wonders if the current edition has been, uh, bowdlerized somewhat, because the first edition used politically-incorrect language that wouldn't pass today. Especially when dealing with the primitives.
I've read the first one several times in my life; the second one only maybe perhaps twice. The first one's about people, the second one's about nature, and people are more interesting than nature.
But neither Johnson was a scientist; they were first and foremost photographers, and whatever science they learned, they learned by accident.