196 Part III — Google Map Hacks
The result can be seen in Figure 10-6. You can see how the information is overlaid, one circle
on top of the other to show the population growth. Of course, the dramatic contrast of shade
and color can be better seen on the book’s web site (http://maps.mcslp.com).FIGURE10-6: Showing the multiple population data using a polyline to simulate circles.The circle example is available at http://maps.mcslp.com/examples/ch10-03.html.