Abstract: The specification discloses a mill including a track having separable sections clamped to ground bearing cross members to which a log to be ripped is dogged. A carriage has deeply flanged rollers engaging opposite track members and supporting a post. A crossarm support is adjustable up and down the post and a horizontal crossarm is adjustable horizontally on the support by a rack and pinion drive. A saw bar of a chain saw is bolted to a quadrant which is quickly adjustable between a vertical position and a horizontal position of the saw bar. A handle on the carriage is adapted to be pushed by an operator to move the carriage along the track, and a bowden-wire control to the throttle of the chain saw is mounted on the handle.