Anyone who watches Poldark for a treatise on Cornish industrial history is clearly barking up the wrong tree – or, maybe, peering down the wrong shaft. The second BBC adaptation of Winston Graham's novels has already secured a sweating, straining place in prime-time costume-drama folklore that promises to eclipse even the spiky courtship of Jennifer Ehle and Colin Firth in Pride and Prejudice – almost 20 years ago. Ask fans to divert their gaze from the unfastened gowns and naked torsos to th...