Miles Gemini G-AMGF

This shows the Gemini that he had first, from “Reach for the Sky” by Paul Brickhill, 1954 Edition, facing page 353.

Scrapped in November 1963, according to the British Civil Aircraft Registers by Dave Peel.

Is this associated with such factors as fuel consumption, emissions control and noise abatement, so the engines don’t need to be so tremendously powerful? After all, as long as the aircraft eventually gets off the ground, who cares how much runway it needs (within reasonable limits, of course)?
I hasten to add that I know nothing about these matters! It just seems common sense that you only use as much power as you need, and no more, especially when the bean counters are watching every penny.

The definitive answer (as far as the period up to 1932 is concerned) is probably contained in the Williams/Gustin book advertised on this web site:
http://users.skynet.be/Emmanuel.Gustin/volume2/
Please note that I have no connection with the authors and publishers, so I hope this is not deemed advertising!

Surely a cannon fires shells that explode on impact, whereas a gun fires lumps of lead!