I got kind of desperate in the firewood department a yesterday. I ran through all of my stash of firewood and was scrounging around burning everything flammable to heat the house. (i won't admit to what I burned) I had a few osage logs laying about and decided to sacrifice a couple of twisted pieces. They weren't really suitable for longbows anyway. Put them burning around 3 p.m. and went back out about 9 p.m. to throw in some more junk wood which was soaking wet and found that the outdoor boiler was up to temp and the osage only half burned. Still had a bed of coals @ 9 a.m. the next morning. Wish I had a barn full of that stuff. By the way it got down to 18 degrees last night and I usually have to load the stove up before going to bed to last till morning.