A, Chart Showing by Months the Average Total Daily Water Consumption In Boston, and by Months the Average Daily Per Capita Water Consunnption. Also the Yearly Average of Daily Consunnption Stated in Total and Per Capita.

1. In this illustration, the curves may be read from either of two different sets of coordinate rulings. Using the horizontal ruled lines, we may read from the curves the average total consumption per day. By reading from the slanting lines, the same curves may be interpreted as the average consumption per capita per day.

2. The scheme of using two sets of coordinate rulings is a valuable one. The scale for

"million gallons per day" should, however, have been shown only at the left, with the slanting line scale for "gallons per capita" placed in the right-hand margin for the sake of clearness.

3. The scale for "gallons per capita" is shown in the second vertical zone of the grid.

Exhibit of thf Metropolitan Life Iniurance Company at the New York Worlds Fair, 103<)

B. Curve in Neon Lights on a Glass Grid Placed in Front of Three Related Curves Painted on a Wall Surface.

1. Tubular form of the neon light lends itself particularly well to the making of illuminated

curve charts without limit in size. Colors are available to give contrast in superimposed curves. Consideration should be given to glare as lights may be too brilliant for easy reading.

2. On the glass-ruled grid for the neon lights above it is unfortunate that the zero line of