Penmarik.

I read some other Howatch that's more intellectual than this, so I was a bit disappointed to find it's not much more than a well written family saga. The Cornish setting and class/gender conflicts were interesting though--dated views of women's and gay men's sexuality but a lot of underlying sympathy for both the terrible and predatory heirs, and the people they trample on. Page-turning certainly.

Poldark fans may be interested in the lengthy mining subplot.