For those who may be interested here's free a book with a lot of
detail about the safe design and building of fireplaces and chimneys.
The title indicates 1889, but if you look at the diagrams and photos
in the book, that date is obviously wrong. The latest photos look
like the early 1960s to me.
Farmers' Bulletin 1889 - Fireplaces and Chimneys
You can download it in several different formats.
Web based forums are like subscribing to 10 different newspapers
and having to visit 10 different news stands to pickup each one.
Click to see the full signature.