On 11/07/2020 08:02, Harry Bloomfield wrote:
BBC News article claiming a 13 year olds intricate calculations
persuaded them to fit 8 browning guns rather than the four planned.
Obviously chances are improved of bringing down an enemy aircraft, the
more guns are being fired, but what is the intricate calculation needed
to prove that?

It seems the guns were aimed to coincide at a range of 250 yards. 250
yards seems awfully distant to me, what they show of the films of the
time, it seems much less than 250 yards, maybe as little as 50 yards,
unless the used telephoto lens?

Article was OK but finally watched the broadcast on iPlayer: don't
bother, no real information in it.

You get a glimpse of one plot with two curves on it (for different
"spreads", I think). No insight at all into the calculations.

A few standard bits of archive footage and girly presenter got a ride in
the two seater Spitfire.

They did suggest they were doing multiplications and divisions with a
hand-powered "Facit" type calculator which you still sometimes saw when
I first went into research labs in the late 60's.