What is a gravity baseboard register?

Christine,
Here in the U.S. before WWII a lot of our houses were heated with coal, big furnace in the basement. If you were lucky it was feed by an auger, if not you had to go down to shovel it in. There was no blower on the furnace, hence the gravity part. The hot air just floated up naturally. In the beginning there was just a big central grate in the floor, ours was in a hallway and the rooms were heated by that. Later the furnace was updated and ducts (large pipes, 6 to 8 inches in diameter) from the furnace to the rooms were installed and these baseboard registers were installed. Some of them were very pretty, they had Gothic style grilles. I wish I could find something I could use to imitate that. The furnace was converted over to gas, but still no blower. So these registers are where the heat came up out into the rooms from the furnace. My in-laws had a new furnace and air conditioning put in, but kept the old registers. Their house was built in 1946. My house was built in 1924, it was a bungalow style, 1 1/2 stories, big front porch across the front. I now live out in the country and cut, load, and carry wood to our house for our wood burning furnace. I am going to be 55 years old in December and I am tired of doing that, been doing that for about 35 years. We bought the donkeys to haul for us, they are looking really good and I am looking forward to not having to haul wood anymore!! Kris