I never gave it a thought that anyone might not know what a clinker was...
A little more here than meets the eye. It also occurred to me that people might not know what "coke" is.... We grew up with it, and here's the story.
We lived in Pawtucket RI, and our kitchen "gas stoves" and some furnaces were powered by manufactured gas. Here's a page that explains manufactured gas, with some pictures of the "Blackstone Valley Gas and Electric Company"... which we could see from the 4th floor of our High School.
MANUFACTURED GAS PLANTS - Tidewater Site, Pawtucket, RI
The gas that came to our homes was extracted in a heat process, from coal. After the gas was extracted from the coal, the chunks of coal became porous. These "rocks" were called coke, and still could be burned in home furnaces.
The coke was hard to burn, and required periodic stoking to keep it burning. When the coke "rocks" didn't burn through,and turn into ashes, the pieces that were left, were called clinkers... The furnaces had moveable grates that had to be shaken with a large handle. The ashes went into the bottom of the furnace, to be taken out with a shovel, and spread out in the dirt driveway alongside the house. When the solid "rock" that didn't burn, bounced around in the grates, it would "clink".
Something more that you didn't need to know: We had a choice of what to burn in our coal furnaces. The best coal was called "Blue Coal" The most expensive and hottest burning coal. Next was Anthracite, which was regular coal, and the people like us, who couldn't afford either, bought "Coke"... the least expensive.
My dad worked nights, before he left for work, he would "bank" the furnace... meaning he would fill the burner with fresh coal... In the early AM when he came home from the mill, he would empty the ashes... If there was a clinker, it had to be removed by shaking, breaking or hammering with a poker. Not easy, resulting in the kind of language seen in "A Christmas Story"... My dad never swore at all. The only bad word he ever used was "little bugger" and I'm quite sure he never knew what it meant.
Fond memories...