Clinkers and ash

I'm very blessed. I know this. There is an abundance of good things in my life. Now I shall add my modest stove to the list, because nowhere in my current cookbooks are there instructions like this:

"QUALITY OF COAL.--In addition to knowing the names, prices, and uses of the different kinds of coal, the housewife should be able to distinguish poor coal from good coal. In fact, proper care should be exercised in all purchasing, for the person who understands the quality of the thing to be purchased will be more likely to get full value for the money paid than the one who does not. About coal, it should be understood that good hard coal has a glossy black color and a bright surface, whereas poor coal contains slaty pieces. The quality of coal can also be determined from the ash that remains after it is burned. Large chunks or great quantities of ash indicate a poor quality of coal, and fine, powdery ash a good quality. Of course, even if the coal is of the right kind, poor results are often brought about by the bad management of a fire, whether in a furnace or a stove. Large manufacturing companies, whose business depends considerably on the proper kind of fuel, buy coal by the heat units--that is, according to the quantity of heat it will give off--and at some future time this plan may have to be followed in the private home, unless some other fuel is provided in the meantime.

Mixed with poor coal are certain unburnable materials that melt and stick together as it burns and form what are known as _clinkers_. Clinkers are very troublesome because they often adhere to the stove grate or the lining of the firebox. They generally form during the burning of an extremely hot fire, but the usual temperature of a kitchen fire does not produce clinkers unless the coal is of a very poor quality. Mixing oyster shells with coal of this kind often helps to prevent their formation."

The Woman's Institute Library of Cookery, Vol. 1, by The Woman's Institute of Domestic Arts and Sciences, 1918.

Let me note that there is a buried structure in my back yard. I originally thought that the squarish bulge in the grass was the remains of an old outhouse. It is an old neighborhood after all. But when I was digging a flower bed I kept hitting chunks of brick along a line parallel to the hump and decided it was a wall from an old foundation. And the dirt is full of clinkers, so now I believe the hump is the remains of a chimney and that the house/barn/shed/smithy/mad scientist's lab was fueled by coal. Or it really was a steampunk outhouse after all.