Now trick films were the sort of first visual magic that the cinema could produce and erm these, these films you would see for example a motor car disintegrate and then reassemble itself, this kind of thing, people's clothes change, drop off and a new set of garments would come on, all this sort of thing, people's faces would change, their environment would change, their chairs would collapse under them and rebuild themselves, this sort of thing which could be done relatively easily once you knew how to do it.