Poet's Corner

[Slipstick Libby]

Mr. Heinlein's Slipstick Libby - get this - did astrogation (that's navigation of a rocket ship) with a slipstick.

They were a pain, particularly the nasty complicated beasties with about 40 scales that engineers had to use. The only reason they were used was because they beat doing the math by hand.

Calculators and computers are a blessing.