Today I read, "The Myth of the Eight-Hour Sleep" - a BBC article published in 2012. This will be an incredibly short response, because the article is essentially a regurgitation of what I have already read. It offers nothing new - it cites Ekirch, and Wehr, just like everyone else. This is so familiar, I am not completely certain that I haven't already read this article.
The one thing it does have to offer is a handy breakdown of the stages of sleep. I leave that for you here: