Bonjour Pierre-Michel,
I agree. This is not a French made prop. It carries entirely English markings. And I'm sure from your posts that it is of French design, in this instance given a British & Colonial Co drawing number of P23, where the designator letter P indicates B & C. The British could not import sufficient French aircraft, engines and props during WW1 so they were made in Britain under licence.
There are no batch numbers ( G & N numbers) because the prop (and Nieu 17) pre-dated September 1917 when the newly formed Air Board started allocating them.
As the French were the world-leading designers of aero-engines and props at the start of WW1, it became the convention to use their nomenclature, in this case mm for millimetres; hence 2570mm. There was a short period in WW1 when the British used Imperial measurements; hence 8ft 5inches. Not only was it done for a short time but only a few makers did it. As you, the French, and us British had been enemies for at least a thousand years of invasion and warfare, perhaps it was a momentary reversion to type!
Avec le Respect,
Bob
|