Was at a classic car rally once, just pottering round, came across a guy with some huge Cadillac or something, bonnet up, engine ticking over, so we, along with a few other people, stopped to look, have a listen. Then we heard another engine start up, sounded a bit different. Tom said "That almost sounds like a Merlin!" and we looked over to where the sound was coming from and.. it was. In fact there were two, each bolted to a trailer, which was very securely pegged to the ground, and with a 'sawn of' stub of propeller on the front. Result: whole crowd legged it over to see, leaving cadillac man all alone...
Amazing. We were kept behind a rope, of course, but the sound was incredible and when the operator revved up (they had a sort of control board bolted on the back) all those in front ducked, thinking it was about to take off!
And let's have a word for the Hurricane, who suffers from being the slightly less curvy cousin, but nonetheless did a better job in some respects I understand...