"Toller" wrote in message
...

Black locust. Best wood there is; only one I use. I sure wouldn't bother
splitting soft woods or many of the lesser hardwoods. I suppose oak, hard
maple, hickory, and a few others are okay if black locust isn't available,
but "most wood isn't worth the effort".

Can't prove it here
http://www.chimneysweeponline.com/howood.htm

There is a correlation between density (weight to be hauled into the house)
and Btu, but that correlation also means greater physical effort to split
the harder woods compared to the softer. There are plenty of good woods
that produce a lot of heat. More volume to carry, but not so much weight.
There are tradeoffs that many of us are willing to make. Especially since
there are not that many black locust trees around here.