I READ with some interest your report concerning the introduction into Scotland of Control Emission Toilet equipment (CET) to our railway carriages (“Train toilet overhaul ends on-track flushes”, The Herald October 16).

I suppose that foretells the demise of the old joke, which relates that it is not allowed to use the toilets when the train is stationary, except when the train is stopped in town A (which is a place of the teller’s choosing, not being high on his list of locations in receipt of his admiration).

Ian W Thomson,

38 Kirkintilloch Road, Lenzie.