Where did the false "equal transit-time" explanation of lift originate from?

Summary

This explanation has probably been independently 'rediscovered' many times, and it is unlikely to be able to point to a particular origin. Ackroyd says in 'Babinsky's Demonstration: The Theory of Flight and Its Historical Background' (Journal of Aeronautical History, 2015): Imagine that two adjacent air elements ... A and B ... are about to reach the aerofoil’s nose. Element A passes above the aerofoil whilst element B passes beneath. Eventually element A reaches the aerofoil’s tail or trailing edge and element B, according to this argument, must reach the tail at the same time so as to regain its position adjacent to element A ... this flawed explanation of flight has survived and still enjoys wide belief, probably because it has the appeal of simplicity. Its origin now seems to be lost in the mists of time although it may be that its use in aircrew training manuals gained for it a popularity which extended to school textbooks and even the occasional British A Level examination paper. Some sources say this explanation is sometimes used in flight training manuals. The above explanation is extremely wide-spread. It can be found in many textbooks and, to my knowledge, it is also used in the RAF's instruction manuals. Source: Holger Babinsky (2003). How do wings work?. Phys. Educ. Vol. 38. p.498. Accessed: http://www3.eng.cam.ac.uk/outreach/Project-resources/Wind-turbine/howwingswork.pdf Ballow speaking about his experience when learning from Air Force training manuals while a member of the Nevada Air National Guard: The training covered the theory of flight as outlined and explained in the Air Force Training Manual [...] Lift is generated by the air passing over the wing. since the upper surface of the wing is curved and the lower surface is straight, the air passing over the upper surface of the wing has farther to travel, and so it is thinned out. Source: Tom Ballow (2005). The New Science of Flight and Movement. p.13. Accessed: https://books.google.com.au/books?id=...