Tolkowsky also developed a geometric model of the crown, on pages 80-94 of Diamond Design . To keep his model simple, Tolkowsky used a knife-edge girdle. This geometric model let him take a given pavilion angle and calculate the best crown angle and table size for that pavilion angle. Tolkowsky gave only one example: He calculated that a diamond with a pavilion angle of 40° 45' looks best with a crown angle of 34° 30', and a table size of 53%. This example includes some rounding errors. This point is starred (*) in Figure 3.