These days horse power is a term frequently used for measuring automotive engine performance or the power capacity of motors. However a century ago, horse power or more often in underground coal mines, mule power was a very real and tangible measure of work. A mule is an offspring of a male donkey (jack) and a female horse (mare). Mules were often preferred over horses because of their superior intelligence.
According to research by British scientists, mules have a faster capacity to learn about spatial relations (figuring out and navigating around objects) than horses or donkeys. This was particularly important in the tight quarters of an underground coal mine. In popular imagination mules are characterized as stubborn, mean, and vindictive.
However, these traits usually result from poor training or a bad handler. Coal mining was tough and back-breaking work. Mule or horse power was an important labor-saving device due to their mobility. One primary job for mules was pulling coal cars along rails from the mining area to the portal or bottom of the slope.
Some mules and horses spent most of their lives underground, rarely seeing the light of day except for a couple of weeks during summer. Here, two miners and a mule stand deep underground at a Wilkeson coal mine, circa 1920.
The post card photo was given to John H. Morris, founder of Palmer Coking Coal Company by his boyhood friend, Dave Cox on December 21, 1967.
