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 black. Wide bars would give a striking visual effect and yet they would vary in one dimension only, so that relative proportions could be easily judged. Wide bars would probably have all the advantages and none of the disadvantages of the methods of either Fig. 19 or Fig. 20. Instead of showing the data of Fig. 19 by either bars or squares, another method would show pictures of bales in rows of different lengths, on the general scheme of Fig. 41. The rows would be the same as the broad horizontal bars, but their numerical interpretation would be less abstract.

Fig. 20 gives a diagram taken from another geography book. This is a much better form of presentation than used in Fig. 19. It could, however, be improved by giving the figures for each country in connection with its own bar.

Fig. 21 shows the horizontal-bar method applied to a larger number of items and proves the great utility of this method when several different items must be shown in their proper rank. In this case, however, the figures should have been given for the convenient use of any one who might wish to make ratios or to quote the actual value of products for any one of the cities. It is exasperating to run across a diagram of this kind which contains valuable information in such form that it cannot be carried away or quoted for use elsewhere.

Department of Surveys and Exhibits, Russell Sage Foundation

Fig. 22. Comparison of School Cost per Pupil in Cities of 25,000 to 35,000 People in New York State

This illustration was photographed down from a wall exhibit to adapt it to a printed report. The use of the figures at the right-hand end of the bars is bad practice. The eye is apt to make the comparison from the last figures rather than from the ends of the bars

In Fig. 22 an attempt has been made to show in the graphic presentation the figures from which each horizontal bar was drawn. The method of placing the figures at the right of the bar is, however, unsafe. The eye is likely to make a comparison, not from the ends of the bars themselves, but from the right-hand end of the figures. Since the figures are of about constant length, visual ratios are inaccurate when made by comparing a short bar plus the constant length of figures with a long bar plus the constant length of figures. If the shortest bar in Fig. 22 were about the same length as the space