Although Watson-Watt's Chain Home was important, it would have been useless without the Dowding System, an astonishingly efficient system for getting radar information to fighters in a matter of minutes. We've all seen it, possibly without knowing what was going on. Those young women were pushing around models showing enemy radar contacts. Meanwhile, other young women in a gallery were passing the information on to RAF bases. Of course both the Dowding System and Chain Home depended on each other, but it's arguable that the Dowding System was more truly innovative.