On a map of the kind seen in Fig. 177 there may be any number of different shadings, from one to a dozen or more. In order to simplify matters for the reader it seems best to assign the smaller numbers to represent those conditions which are considered most desirable or commendable. The reader may then see instantly which areas are first, second, third, etc., in rank simply by observing the figures inside the small circles.

In Fig. 178, if it be assumed that there is a likelihood of corn crops going up to 60 bushels per acre, the scale intervals are shown as uniform. Fig. 178 is of interest chiefly because it shows what can be done by hand ruling when it is necessary to produce an illustration for a report in which an expensive cut by the Ben Day method cannot be justified.

Fig. 179 does not do justice to the possibiUties of the Ben Day method of shading. The cut was made by photographing a page of the Census Abstract which was printed on rather rough paper. With an original cut made directly by the Ben Day process the distinction

GRAPHIC METHODS

between the different shades would be considerably clearer than it is in Fig. 179. A cut of this size and complexity is rather expensive when the Ben Day shading is used. Anyone wishing a cut made with Ben Day work would do well to get a rough cost-estimate from his engraver before actually giving the order.