Why are pitching mounds 60 feet 6 inches away from batter?

The "feet" or "foot" sign was confusing to the first guy who first read and measured it. The (60ft) was read (606"). The pitching mound was moved back from 50' to 60'6" in 1893 (the last change in the dimensions of the field) in response to the practice of "fast pitching" in the league at the time. Pitchers had been pushing the envelope of the rules governing how a pitch could be delivered to the plate for years and the great Giant's pitcher Amos Rusie was probably the fastest pitcher of his day.The distance was adopted to level the playing field between hitters and pitchers. It should be noted that it took pitchers years to catch up at the new distance and the 1890's were an era of very high team and individual batting averages, the all time highs in these categories were set then and have never been surpassed. Hugh Duffy of the Boston Nationals set the all time record for a single season BA in 1894, alternately recorded as .438 or .440 and it was common for team BA's to be well over the .300 mark.