A bluecap is a brownie or spirit who worked in the mines of Northern England as a putter, a man or boy employed to push wagons out of the mines. They were usually unseen, appearing only as a blue light;[1] miners would sometimes see the flickering light settle on a full tub of coal, transporting it as though “impelled by the sturdiest sinews”.[2] If treated with respect, bluecaps might even lead miners to rich deposits of minerals.[3]

The blucaps were said to be hard workers, but unlike other brownies they expected to be paid a working-man’s wage. Their payment was left in a solitary corner of the mine, and they would accept no more or less than they were owed, the same as any other putter was paid.[2]