Mayhew (plaintiff) was hired by Sullivan Mining Co. (Sullivan) (defendant) to find new lines of ore deep within mines. Mayhew worked on a wooden platform almost three hundred feet below ground. Near the corner of this platform was a “bucket hole” that Mayhew used in his work. One day, Sullivan allegedly cut a large ladder hole in the platform. Sullivan did not place a fence or barrier around the new hole, and did not inform Mayhew of its existence. Mayhew fell through the hole and was severely injured. Mayhew sued Sullivan for negligence. At trial, Sullivan requested it be permitted to ask questions of expert witnesses as to the “custom” of building barriers and fences around ladder holes that deep underground. The trial court refused to permit these questions. The jury found Sullivan was negligent and awarded Mayhew $2,500 in damages. Sullivan appealed.