We installed this piece (many cranes and rigging operations) in the bitter cold in January 2004. I'm grateful to Tallix (a foundry in Beacon, New York) and to United Concrete (Yalesville, Connecticut) for all their help.

It is called "Larkin's Twig" because several years before the installation Graham Larkin, then a graduate student in Art History at Harvard, worked as my intellectual assistant, teaching me some art history and providing materials to read and think about in a kind of correspondence course and tutorial. When Graham came to visit, he would bring a little something each time, such as a book or, once, a beautiful twig about 12 inches high with a very nice natural geometry and graceful, but not mechanically graceful, curves. For years, Larkin's twig sat in an honored place in our library and then in our kitchen.

Why not make the twig 32 times bigger? How will it scale up? Should X, Y, and Z scale up differently? (Yes) What should the material be? How will the steel rust? What parts should be revised, extended, modified, reshaped? How is it to hit the land? How will it belong in the natural environment of the landscape? In relation to trees, land contours, and other pieces in the field? What is the proper orientation of the piece and the resulting cast shadows? How will shadows vary in different seasons of the year? How can mock-ups be built to test ideas out? What about structural engineering issues? A Cooper's Hawk perched on a two-thirds scale wooden mockup, will that happen on the steel and do we add a bird-perch? What does it all mean? And so on.

For more on Larkin's Twig and other artwork by Edward Tufte visit edwardtufte.com