| Rating | Solver | Clue |
|---|---|---|
| KEROSENE | Fuel substance | |
| COAL | ...bstance, dug from beds or veins in the earth to be used for fuel, and consisting, like charcoal, mainly of carbon, but more compact, and often a... | |
| PEAT | ...urated with water. It is often dried and used for fuel. ... | |
| SOOT | A black substance formed by combustion, or disengaged from fuel in the process of combustion, which rises in fine particles, and adheres to the... |