1. Broad Flat Mandrels marked F 1. in Plate 15. with three or more little Iron Pegs, or Points, near the Verge of its Flat: And these are used for the Turning Flat Boards upon. For the backside of a Board placed Flat upon it, will when screwed up tight between the Pikes, by help of the Iron Pegs, remain in its place and position, whilst the Flat side of the Work is working upon.
Behind the Backside of this Mandrel (and indeed all other Mandrels) is fitted a long Shank, or Rowler, for the String to be wound about while the Work is Turning. This Rowler must be so large in Diame∣ter, that the String wound about it may command the Work about. If the Work be large and heavy, the Rowler must be bigger than if the Work be light; for else the String will not command it about: But if the Diameter of the Rowler be smaller, the Work comes so much swifter about. The Rowler must also be so long between its Shoulers, that it may conveniently contain so many Diameters of the String as shall be necessary to wind about it.
This whole Mandrel is marked F 1. in Plate 15. •• The Round Flat, or Face, of the Mandrel. b The Row∣ler. cc The Shoulders of the Rowler. ddd The Pegs.