From the first chapter of 猫城记 by 老舍, we see examples where 的 is used where I would expect to use 地 (to indicate an adverb):
I'm not sure what's going on here. I have some speculations (e.g., maybe it's a historical or geographical difference) but I'm just guessing. I don't think it's a typographical error (I bought the book, and it's the same in the print version).
Question: In 猫城记, why does 老舍 use 的 (instead of 地) for adverbs?