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46 History and Science of Knots

          of the ancient Egyptians are difficult to retrieve, but they certainly will have
          been different from those of twentieth century England. Therefore, the com-
          position of rope and string is indicated by a descriptive formula, rather than
          implementing present-day English terminology. The same hesitation should
          be felt in applying English names for knots to those found in Egypt. Since
          the complexity of knotting formulas will entangle most readers, the knots are
          recorded by two drawings: one conveying the appearance, the other showing
          the construction. An exception is made for the five most commonly occurring
          knots: the half knot, overhand knot, reef knot, granny knot and mesh knot.
          For practical purposes the names of these well known knots are used below.
          The orientation of these knots is indicated in the same manner as that of rope.
              The rope formula indicates the direction of twist and the number of
          strands used. The direction of twist is indicated by a letter S, Z or I, the mid-
          dle stroke of the letter indicating the three variations (Fig. 2). The direction of
          twist varies at the different levels: usually spinning, plying and cabling are ori-
          entated in opposite directions. Thus zS2Z3 rope consists of fibres spun in the
          z-direction(z). Two of those strands are plied in the S-direction (S2). Three
          of those S-plied, z-spun strings are cabled in the Z-direction (Z3 see also:
          Wendrich 1991: 32). Throughout the entire Egyptian history, the ropemaking
          orientation encountered by far the most is zS2.
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             Fig. 2. The direction of twist for spinning, plying or cabling is indicated with a
             capital letter S, Z or I, the middle strokes of the letters indicating the orientation
              The same indications, S and Z, are used to indicate crossings and orien-
          tations of knots. Crossing strands can be orientated overS or under S; overZ
          or underZ (Fig. 3). Overhand knots (Fig. 4) or mesh knots (Fig. 5) are S- or
          Z-orientated. Reef knots are made of two half knots in opposite orientation:
          they are either SZ or ZS orientated. Granny knots are made of two half knots
          in the same orientation: SS or ZZ (Wendrich 1991: 42-3).
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