Monday, July 09, 2012

Topography

Somewhere at Stonehill College (I hope) are stored dozens of plastic relief maps of the United States. These are the maps originally produced (as I recall) by the U. S. Army and subsequently manufactured and sold by Hubbard Scientific. Each sheet is about 24x18 inches (100x70 miles), with vertical relief exaggerated three times. By trimming off two margins, they can be mosaicked together into spectacular room-sized, three-dimensional displays.

Which is what I used to do when I was teaching a general studies course in earth science.

I chose my classroom carefully so that the early morning sun would cast shadows that accentuated the relief. Pushed back the desks against the walls. First the eastern United States, filling the floor. Then, a few days latter, the west. (The middle of the country is too flat to warrant topographical relief.)

And we talked, applying what we had learned to the shape of the land. Plate tectonics. Ice ages. Human history. Lordy, those maps were great. We could have spent a whole semester with them on the floor. (Whence Cape Cod? Why does driving across Pennsylvania take you back and forth in geological time? What's with the Great Salt Lake? Where shall we breach the Appalachians with a canal? A transcontinental railroad; where's it gonna go?)

If they haven't been thrown out, the maps should still be in a big cabinet in the college observatory, where I had them moved when I vacated my office. I haven't heard that anyone has used them, which is a shame. They are a fabulous teaching resource.

And here's the thing: I learned more than the students. In fact, I think it's fair to say that I never understood much of anything until I had to explain it to someone else.