Re: Entire article fails to mention the other factor... @Nick Ryan
" I'll be buggered if I know how to use a slide rule either." Poor chap! I got my first one at age 11 - celluloid glued to paper glued to wood. Necessary for School Certificate Physics and Chemistry.
Plastic eventually took over, and I've still got a Faber Castell I used much later.: folded dual scale (so 10" was effectvely 20") with reciprocal scale in the centre of the slide, sin, cos, tan scales on the back (not to mention the bibulous shin, cosh, and tanh), and a little KW to HP coversion offset on he cursor..
Who needs a calclator?
Yes, I know, some Japanese whizz-kid with a soroban (abacus) can do it faster!