Bulgarisches Frauenlos stand schlicht und in stummer Natürlichkeit an manchem der neuen sauberen Bahnhöfe; ein Eisenbahnunfall lehrte vier Stunden in der Nacht auf einsamer Strecke das Warten in Gesellschaft jener unzertrennlichen Begleiter südlicher und östlicher Heere, die sich in den fetten Polstern der Wagen eingenistet hatten.
In the first clause, I am unsure how to translate
Bulgarisches Frauenlos stand schlicht und in stummer Natürlichkeit
and I am not totally sure how to parse the second, but I think it simplifies down to:
ein Eisenbahnunfall lehrte das Warten
(a railway accident taught waiting) but I am not sure how to translate this sensibly into English. Perhaps the sense of it is something like
The lot of Bulgaria's women was revealed simply and silently at several of the clean new stations; a railway accident had forced us to wait patiently on a lonely stretch of track at four in the morning, in the company of these inseparable companions of the southern and eastern armies, who had settled themselves into the plump cushions of the wagons.
but I am unclear on several points. For example, is it clear whether it is the armies or the companions who have sich eingenistet haben? (I am assuming it is the companions.)