People that know very little of arts or sciences or of the powers of Nature...will laugh at us Cardiganshire miners that maintain the being of knockers in mines a kind of good natured impalpable people but to be seen and heard, and who seem to us to work in the mines however this is, I must speak well of these knockers for they have actually stood my very good friends.
    whether they are aerial beings called spirits, or whether they are people made of matter, not to be felt by our gross bodies, as air and fire the like.
    Before the discovery of Esgair y Mwyn mine, these Little people (as we call them here) worked hard there day and night, and there are abundance of honest sober people that have heard them; (although there are some people amongst us who have no notion of them or of mines either), but after the discovery of the great ore, they were heard no more.
    When I began to work at Liwynliwyd they worked so fresh there for a considerable time that they even frightened some young workmen out of the work. This was when we were driving levels and before we had got any ore, but when we came to the ore then they gave over and I heard no more talk of them.
    Our old miners are no more concerned at hearing them blasting, boring holes, landing leads, than if they were some of their own people, and a single miner will stay in the work in the dead of the night without any man near him and never think of any fear or harm that they will do him, for they have a notion the knockers are of their own tribe and profession and are a harmless people who mean well. Three or four miners together shall hear them sometimes, but if the miners stop to take notice of them the knockers will also stop; but let the miners go on at their own work, suppose it is boring the knockers will also go on as brisk as can be in landing, blasting or beating down the loose. And they are always heard at a little distance from them, before they come to ore.
    These are odd assertions, but they are certainly facts, though we cannot and do not pretend to account for them.

LEWIS MORRIS ( 1700-1765 )