Studies of the percentage of clerical work and percentage of revenue from orders of various sizes. Pin boards to record costs of doing work on orders of different size. Theoretical curves for percentage of clerical work and percentage of revenue from orders of different size. The Lorenz curve. Correlation curves. "Shotgun" diagrams. Plotting curves to represent numerous points. Shaded areas to represent numerous dots. Correlation charts for two independent variables. Isometrically ruled paper for chart work.

Chapter XI. Map Presentations 208

Map presentation of prime importance. Shading of different areas. The Ben Day method of mechanical shading. Lines of equality. Profiles. Maps with circles or dots representing quantities. Shaded areas with a key to represent quantity. Miscellaneous methods. Map charts showing traffic. Map models with built up strips to show quantities.

Chapter XII. Maps and Pins 227

Map tacks projecting above the map. Map pins pushed in till the heads touch the map. Photographing pin maps. Mounting maps for use with map pins. Wall maps for use with pins. Map cabinet systems. Pin maps for advertising work. Pins bearing identifying numbers. Spot maps to a scale with each dot representing some large quantity. Routing systems. Various types of pins and beads available. Bead maps and their great advantages.

Chapter XIII. Curves for the Executive 254

Peak-top curves versus flat tops. Methods for combining curves with figure^ recording the data. Cards for plotting curves for operating records. Advantages of the card method for instantaneous comparison of different curves. Typical operating curves for a manufacturing business. Typical records for a selling organization. Arrangement of the card system for extension with increase of business. Moving average curves for operating records. Record cards for preserving all information regarding each curve.