Sir – Your arrogant columnist has excelled himself yet again (Gray Matter, February 18). He finds the caricature cartoon of Adolf the Tank Engine incomprehensible, and cannot understand why some people might find it offensive.

Maybe it is just too subtle for him. Perhaps the cartoonist should have been more blatant — say in writing ‘cattle truck’ on the side of the wagon (it clearly is not a carriage), or perhaps showing the ‘Arbeit Macht Frei’ sign in the background.

How about a name-plate on the engine, such as Auschwitz Express? Maybe then Mr Gray would understand.

Simon and Rhona Walker, Charlbury