- She was in the street just outside of the bakery, so the postman handed over the letter directly, saving him the trouble of going inside.
- In answer to the second question: Pretty much. Chesterton wasn't a "hard" sci-fi writer, he simply postulated something that seemed not impossible because he needed it for his story. Though it wouldn't have seemed quite as implausible at the time, there were a lot of such things wandering around the sci-fi and speculative fiction of the era.
Headscratchers / Father Brown