Having wandered into the first exhibition encountered on walking over from the ticket office, my first impression of the Royal Gunpowder Mills in Enfield was poised to be this interesting-looking display of missiles connected to post-war work here, but of a sudden, the air was rent by an enormous voice, volume turned up to maximum, and the continual squeals and squeaks of surprise of small children.
  Curiosity? You bet! (But I hadn't brought the earmuffs I use on the rifle range!) In a - I suppose you would have to call it a lecture - um - shed - was Professor Nitrate: rather well-named, I thought, in view of the explosive delivery of his lecture.

  Gavioli fairground organ.