Worked on a farm that had a gravity coal furnace. It burned rice size coal (3/16″ to5/16″). An auger fed the coal from a hopper into the center of the furnace. The coal was push up a tube where it would mushroom up onto a round plate to burn. The ash would drop off the side of the plate to the bottom of the furnace where another auger would take it out to a small conveyor. The conveyor would carry the ash up high enough for it to drop into a 5 gallon pail. The pail would need to be changed 2 or 3 times a day depending on how fast you were feeding the coal. The hopper held enough coal for a couple days, again depending on how fast you were feeding the coal. You could slow it down enough to last several days if you needed to be gone before the hopper would run out. You would have to pick the ash up off the floor. The ash was spread on the drive where needed. Next job was
working at the coal yard that delivered that coal.
Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.