Three employees stand by a large log in a lumber mill. This appears to describe what is happening here: ""Most early mills produced boards by means of large circular saws. Logs were secured on a movable platform (�carriage�) and fed into the rotating saw. The first pass removed a slice of bark and wood (�slab�) from the side of the log; the log was then turned a quarter-turn on the carriage and another slice was taken. Four trips through the saw would yield a square-sided cant which could then be sawed into boards."" (http://www.state.sc.us/forest/scindust.htm)