The “mop and pail” in the computer room were a constant theme for mainframes in the late 1950s and 1960s. In this cartoon the “it” is unclear, which is part of the humor. Is the “it” referencing computing in general, the fixation of people with computers, or an attempt to converse with the machine, or other possibilities?1

Mop and pail computer cartoon - The New Yorker 1957.
"I've had it explained to me, but I still don't understand it."

  1. Cartoon by Alan Dunn, The New Yorker, October 5, 1957. Listed in The Complete Cartoons of The New Yorker, by Robert Mankoff and David Remnick, 2004. ↩︎