To set the scale, PROC CHART uses the maximum value from the AXIS ... specifies the variable for which either values or means (depending on the value of TYPE=) PROC CHART displays in the chart.

Starting at an everyday scale, we travel by powers of 100 down into the shadowy world of strings. That is, we begin 10 meters away from an apple, then zoom 100 times closer to 10 centimeters away ...