Slide showing two line charts; fig. 6.1 illustrating the 'frequency-polygon for Head-breadths of 1000 Cambridge Students', and fig. 6.2- a 'histogram for the same data as fig. 6.1.' Slide shows two line charts; fig. 6.1 illustrating the 'frequency-polygon for Head-breadths of 1000 Cambridge Students', and fig. 6.2- a 'histogram for the same data as fig. 6.1.' Fig. 6.1: The Y axis is labelled 'Frequency per 1/10th inch interval of head breadth', and ranges from 0 to 250. The X axis is labelled 'Head breadth in inches', and ranges from 0 to -8. Fig 6.2 has identical ranges and labels to fig 6.1. Late 19th to early 20th century