jet engines

how do you explain the jet engine to a nearly 4 year old? its difficult enough trying to explain why coal is useful to a steam engine, and why Dr Beechings destroyed so much of our legacy though the current thinking is that he probably saved the railways from complete banruptcy. I remember the tram station outside the Harris Bacon factory in Totnes from nearly 40 years ago - it has the corrollaric thrill that the Science Museum's marine section gives me in terms of strange deep water phobia....

,,, Gal is crying... give me a mo