Cogs and belts... I wonder if anyone has ever counted how many wheels there are in the museum? There must be hundreds on all the various machines. What a great invention the cog wheel is, with all those interlocking teeth that transfer the drive power. Many of the machines in the museum are protected by sheets of perspex - to prevent people poking their fingers in, I suppose. It is rather annoying if you want a clear photo but I actually quite like the muted 'underwater' effect that it gives.