What about the archaic language? He doesn't go full 'thee and thou,' but he does use period-appropriate vocabulary and phrasing. It's never impenetrable, but it demands a bit more attention than modern prose. Sentences can be long and complex, mirroring 19th-century speech patterns. I actually find it adds to the immersion. After a few chapters, you adjust to the rhythm. It's like listening to a piece of music in a different time signature—confusing at first, then natural. If you're coming from fast-paced, minimalist modern fiction, give yourself a grace period to get used to the cadence. Don't fight it; let the prose wash over you. The payoff in atmosphere is worth the initial effort.