Chris injects enthusiasm and layman understanding into various machines and their history, ranging from rockets to trains. Very enjoyable, as complex engineering feats are explained by Chris in a non patronising, entertaining and clear manner. And you can get away with watching it without feeling too much of an anorak... His use of props to explain and demonstrate is amusing. The only episode I didn't particularly enjoy was the one about tanks, mainly because despite blowing stuff up it hardly showed the best of human ingenuity. Still, rough with the smooth I suppose and one dodgy episode shouldn't tarnish the whole series.