One edge of each overlay is then taped to the front of the frame. During projection, overlays may then be selected and folded over the base film. Cullather thinks the map of the Ap Bac battle has been especially effective. In this encounter, the American troops mistakenly assumed that the Viet Cong would be defending the village, rather than the century-old system of dikes that they used for transportation and irrigation. The map allowed us to do that in a sophisticated way, and I found that it really raised the intellectual level of the course.
Students frequently refer back to that battle now.
The Ap Bac transparency series was made up of five films which he overlays sequentially to describe the battle. The base map contains geographical features such as villages, canals, and tree lines, together with an inset map locating the territory in Vietnam. With the help of the Teaching and Learning Technologies Lab, Cullather is putting the maps on his A300 World Wide Web site. In fact, once the complete image has been created, the components for each layer can be separated and printed with perfect registration. These pages are best viewed with Netscape 2.0 or greater.