Mindful of schools where every teacher had a laptop or an interactive whiteboard, he toured the backstreets of Birmingham trawling for kit. Then he spotted the ultimate must-have object: a pocket-sized, almost unbreakable device capable of gaining any child's attention.
"It is called the ACME Thunderer," he says proudly before conceding that the awesome equipment, which he bought half price, was a whistle.
"It's not just any whistle. It is the classic, shiny, silver one with the pea in it, the one Football Association referees are equipped with," he says .
The Thunderer is indeed a prince among its peers. Invented in 1884, it is, according to its makers, "the first and still the world's leading pea whistle, offering total reliability, control and power."
Features include "a waterproof speed pea that works in rainstorms".
The Diary does not wish to make readers too covetous, but every member of staff at St Giles now has a Thunderer around their neck. Mr Jelley insists the equipment is proving invaluable: "A whistle is a wonderful thing. It is excellent at getting children's attention. It says 'stop, listen to me'."
Or, as the poet Roger McGough said in a poem about the Thunderer: "He who owns the whistle, rules the world."
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