The two failures
Full pastiche tries to counterfeit a period novel sentence by sentence: inversions, thees, a fog of archaic connectives. Almost no one can keep it up for ninety thousand words, and readers tire of it in twenty pages. It draws attention to the costume. The story becomes a demonstration of dialect.
Full modernity fails the other way. The narrator winks, the syntax belongs to a group chat, the metaphors are airports and batteries and bandwidth. Each one is a small tear in the agreement that we are not here. A few tears and the century is a backdrop again. The reader starts correcting you instead of following you.
A clean sentence, seasoned
Write a sentence a contemporary reader can say without stumbling. Then season it. Diction: the words they would have reached for — portion, credit, melancholy, a living, a place — rather than the analysis we would reach for. Rhythm: the length of a thought before a person of that rank and education would stop. Metaphor: drawn from their work and their weather, not from ours. A sailor does not think in railways he has never seen. A clerk might.
Seasoning is light on purpose. One period turn in a paragraph does more than a paragraph written in fancy dress. The narrative voice can be a little clearer than any single character’s speech. Characters may be knotty, dialectal, formal. The narration has to travel the whole book without exhausting the ear.
Read it aloud
The aloud test is blunt and reliable. If you stumble, the reader will. If you hear yourself performing — a put-on accent, a teacher’s voice, a joke you would only make to your own century — rewrite the line until you could imagine saying it to someone who shares the room. “If you would not say it, neither would they” applies to narration as well as to dialogue.
Aloud also catches the lecture. A sentence that exists to inform has a different music from a sentence that exists because someone is in trouble. Prefer the second music. Information can ride inside it.
One voice, held
Choose the distance and keep it. A close third that suddenly knows the future of the nation, or a cool narrator that suddenly kneels inside a fever, throws the reader out. Historical fiction already asks for a great deal of trust. Do not also ask the reader to renegotiate the contract every chapter.
Collect a short list of banned words — the ones that drag 2020 into the sentence — and a short list of allowed flavours, taken from your primary reading. You are not imitating a dead stylist. You are building a dialect of your own that can walk through their streets without looking at its phone.
Try this
Read one page of your draft aloud. Circle every word you would not have said in that year, and every sentence you performed rather than spoke. Replace the words from your source notes. Rewrite the performances as plain lines with one period seasoning each.