Flute acoustics: an introduction to how a flute works(newt.phys.unsw.edu.au)
newt.phys.unsw.edu.au
Flute acoustics: an introduction to how a flute works
https://newt.phys.unsw.edu.au/jw/fluteacoustics.html#words
https://newt.phys.unsw.edu.au/jw/fluteacoustics.html#words
It contains detailed explanations of his development process, including a complete schema for determining optimal tonehole positions - developed after he first created a flute in which he could move them!
It helped me to more deeply appreciate the engineering marvel that is the modern western concert ‘Boehm’ flute. It’s an exceptionally pure instrument.