The compound rest (or top slide) (2) is usually where the tool post is mounted. It provides a smaller amount of movement (less than the cross-slide) along its axis via another feedscrew. The compound rest axis can be adjusted independently of the carriage or cross-slide. It is used for turning tapers, to control depth of cut when screwcutting or precision facing, or to obtain finer feeds (under manual control) than the feed shaft permits. Usually, the compound rest has a protractor marked in its base (2b), enabling the operator to adjust its axis to precise angles.