The story I remember about the state of Physics back 110 years ago (or a bit before), was a belief that pretty much everything had been discovered, and all that was left was a narrowing of error margins (more precise measurements). What we got a bit later was some fairly large conceptual leaps...
Backwards?
Both "ether" and "dark matter" were offered as - in some respects - similar explanations. In the end the purposed theory for "ether" was rejected when what we knew advanced enough that the equations did not work out. We are not yet that far along with "dark matter". Both "ether"...