Figure from 'Aerial Flight - Volume 1 - Aerodynamics'
<bdi><a href="https://en.wikipedia.org/wiki/en:Frederick_W._Lanchester" class="extiw" title="w:en:Frederick W. Lanchester"><span title="British polymath">Frederick W. Lanchester</span></a>
</bdi>
<a rel="nofollow" class="external free" href="https://www.thermiksense.de/wp-content/uploads/2018/06/lancast.pdf">https://www.thermiksense.de/wp-content/uploads/2018/06/lancast.pdf</a>