Met Techs Course at Shinfield Park c. 1980 [an ex-RAF HQ near Reading]
Mercury Barometer Servicing lesson.
Teacher: "Bloggs, what the bloody hell are you scrabbling around on the floor for?"
Bloggs "all the little ball-bearings have fallen out and are all over the place!"
NB. In these H&S awareness days,
1. mercury baro. not used and
2. if they were, incredible precautions would be taken.
Difficult to legislate against an outbreak of Bloggs, though.