Hadley Boxes and coffee
Working in the tower on an East Anglian fighter field one day (before my days in Caravans), staff had been read the riot act about coffee constantly being spilt on the Hadley Box, you know the one with switches labelled from left to right such as "Stn. Cdr, Wg. Cdr Ops, OC xxSqn OC xxxSqn,OCEng" etc etc, and which required constant cleaning/repair by the guys down in Ground Radio, when Baseball comes up to local to chat with local controller and sets coffee cup down right next to said Hadley box and... yes, you guessed it , with a sweep of his right arm, gesturing to something or somewhere on the airfield the contents of an almost full cup disappears into the device. It went very quiet for a few seconds before I was instructed to call Ground Radio and get the box changed before a very red faced SATCO quietly got up and departed downstairs to his office. Oops
The following day a missive was promulgated which forbade all staff and visitors from placing drinks on the pedestal containing the Hadley Box, and a large sign screwed next thereto.