Trojans: Traced

I printed a grayscale version of the final image on a transparency sheet and put it on a transparency projector and blew it up on the gymnasium wall. In an earlier experiment I found that using pencils to draw on this type of masonry is not efficient. I needed to sharpen the pencil every 10 seconds. So I thought charcoal sticks or oil pastels might be too messy. It was then I happened to have discovered Korn's Lithographic Crayons hidden in one of my cabinets. They look like they could be 100 years old. Who knows how long they were in there.I had the students trace the projected image with the crayons and it went pretty well.