I think T.O.M. Sopwith's comments on examining a Wright ( a "B"?) aeroplane in the USA in 1911 are interesting:
"Speaking from a mechanical standpoint, I think the Wright machine is a monstrosity. I don't see how it could be any worse and still it seems to fly reliably. As you say in this country it seems to get there, but that chain from the motor to the propellers is a very bad arrangement. The chain is the worse feature of the Wright machine, but the slow motion of the propeller makes up for it at least partially.
If you can get the power from a propeller making 500 revolutions per minute you will get about 75 per cent efficiency out of your machine. If the propeller makes 1,200 revolutions per minute you can only get about 50 per cent efficiency. That is what gives the Wright machine an advantage. With its two propellers it gets power without making as many revolutions as where a single propeller is used, and I think the advantage in efficiency more than makes up for what it loses by having that horrid looking chain"
Quote from "Sopwith - The Man and the Aircraft" by Bruce Robertson 1970