Jennings Follows a Clue

The second story in this series came out in 1951 where Jennings feels inspired to take up the career as a detective with Darbishire as his assistant, trouble needless to say is just around the corner.

The twosome first of all detect the lights being on in the sanitarium when nobody is supposed to be in there which is the catalyst for them investigating it and the laundry room before noticing the school sports cups, to which competitions are due have disappeared!
They see a main of that they believe to be a piano tuner leave the building with them and follow him, breaking school rules into the village going into a silvermith and jewellers oblivious to this being his occupation and that he was to engrave them for the school by permission!
Meanwhile all this detective stuff is becoming something of a distraction  not just to Jennings and Darbishire but within their form leading to a number of mishaps not least being caught having defaced a textbook and not paying proper attention in class which results as did for many of our generation in a lecture and a caning from the Head.
While exploring the sanitarium they get caught by a mysterious person who locks them in a room and after escaping, investigate laundry as they lose a clue to only end up being driven  away as the school sports is taking place. In the end they found out who really stole the cups in time for presenting them.
It's a hilarious account of schoolboy life that could only exist pre internet and cellphone.
The edition I own is the 1967 Collins hardback which keeps this dust jacket.