For the Cornish miners of the American West, the dangers of their work led them to believe wholeheartedly in the existence of underground elves known as Tommy-knockers.

Life in the mines was dirty, dangerous, and often unproductive.  The Cornish miner approached the task with irony and good cheer.  The difficult and often mysterious nature of mining led the Cornish to develop their belief in the Tommyknockers -- a superstition that helped explain the unexplainable.

Originating in legend, Tommyknockers were said to be direct descendants of ancient elves known as Vugs and Piskies.  After emigrating to the American West, the elves became Americanized and grew to be as important to the miner as his tin lunchbox, hard hat, carbide lamp, and double jack.  Many Cornish miners refused to enter a mine until assured that    Tommyknockers were on duty.

According to stories handed down from one generation of miners to the next, two kinds of Tommyknockers inhabited the mines -- the friendly, helpful elf and the mischievous nuisance elf.  Both are described as 'little men about two feet high” dressed in miniature mining attire complete with tiny picks, hard hats, and lunch buckets.  The elves who befriended the miners were said to watch over the miners' children; and, more importantly, to work alongside the miners deep in the mines, leading them to rich ore veins, testing shaft conditions, prying down loose rocks, and issuing life-saving warnings of cave-ins, water leaks, and runaway carts by tapping on air pipes or timber supports.

In a 1957 interview, retired miner Fred Nettell, a member of a pioneer Grass Valley, California, Cornish family, described the miners' attitude toward Tommyknockers:  “When a Cornish miner of the old school tells you how his life was saved by a Tommy-knocker's warning, he is not being facetious.  His respect and feeling toward these underground elves is almost religious.”

As a token of gratitude to the helpful Tommyknockers, the miners often left behind pieces of their traditional lunch of Cornish meat pasties, a meat pie comprised of beef, onions, parsnips, and potatoes covered by a flaky crust.

But the activities of the nuisance Tommyknockers were meant to bedevil. These Tommy-knockers would blow out candles, upset lunch buckets, and hide tools.  Some miners told of reaching around rock ledges and encountering the handshake of tiny hands.  Mischievous Tommyknockers, miners believed, sometimes held all-night jamborees in the mine's mule barns.  Thus, on days of low productivity, miners could report to critical shift bosses that their tired mules had been kept up all night by reveling Tommyknockers.

Some unromantic engineers and geologists explained the manifestations of Tommyknockers as natural phenomena.  Sounds in the tunnel depths, they said, can be greatly magnified, and what could be interpreted as the distant tapping of an elf was simply a creaking timber or the metallic drip of water onto ore.  These literal-minded souls found, however, that trying to persuade Cornish miners to their view was like trying to push back an ocean wave.