A fascinating one GB. Whether designed by Saulnier (the Frenchman), or implemented by Fokker on the legendary Monoplane ('Scourge of . . ' and all that), or patented by Schneider the Swiss, or by Euler before then, whether a deflector device (dodgy!) or a truly synchronised mechanical, hydraulic or (later) a solenoid-operated electrical device, it was a great leap forward and as ever, done by stages, in different places, by similarly smart people.
The sort of thing that young Biggles used to talk about, when he was winning WW1 above the western front in the Royal Flying Corps with a Sopwith Camel, in the first stages of his 50 year career as a man of action. Sort of thing that had me hooked as a child - and still does to some extent. It's very sad . . .
