My story is about the headmaster who eventually replaced Mr Holmes (after, as I recall a some what disastrous decline in discipline during the 'gap' between headmasters).

I cannot remember his name but the new headmaster was very fond of thumping the lectern during assembly, to emphasise the point he was making.

A few boys, who shall remain nameless, had 'acquired' some railway detonators.

Detonators used to be placed on railway tracks during fog, to warn train drivers of red signals. They made a very loud bang when a train went over them. They were round, thin and about an inch and a half in diameter. Just the right size to be hidden under a leg on a piece of furniture...

It was decided that prior to assembly, four detonators would be placed under the lectern, one under each leg. The aim obviously being to create a somewhat dramatic effect when the lectern was thumped.

That morning, attendance at assembly must have been a record high!

There was an expectant air as those in the know, i.e. most pupils, waited for the lectern to be thumped. Fortunately (although that is not what we thought at the time) the thump never came.

I assume the detonators were found later because after that assembly, the headmaster never thumped the lectern again.