I saw a show about steam engine enthusiast Fred Dibnah on the telly today. A couple of things struck me in the commentary:
1) Someone being interviewed talked about Victorian times being the era of 'well-built buildings.' Maybe that's true -- but you're sure can't determine it by just looking around you at the buildings built now and those built then. That's because your samples aren't the same. For today's buildings your sample is essentially 'all buildings,' while for Victorian buildings your sample is 'the best constructed victorian buildings.' A little Welsh miner's shack built in 1850 just ain't around anymore!
2) These folks were waxing all nostalgic about the beauty of steam presses, etc. Of course, for the sentimentalists of the 19th century, those were the dark Satanic mills! (The site linked to capitalizes 'Mills', perhaps thinking that Blake meant James and John Stuart.)