The Ideal 65 is a coal-fired sidearm heater, made of cast iron. You flip up the door on top and dump in coal. Water enters at the bottom, is heated, and rises into a storage tank.
There is a grate designed to flip and dump the ashes into the bottom of the device. The open door permits removal of those ashes.
A damper, seen in the center of the ash door, provided temperature control. There is a hole in it. A pull-chain hooked into that and to the flue, so that when the flue started to heat up, it would damp the fire.