In the same spirit I would recommend that you try section 2.2.4[1] of the SICP textbook using The SICP Picture Language [2] which can be found here [3].
That section is based on the same original paper, and it is very nice to check on the book's explanation using a modern environment such as DrScheme.
Thank you so much! I first encountered this article back in 2004 or 2005. I just remembered it again about a month ago, and have been fruitlessly Googling for it off and on since then. You've really made my day!
http://docs.plt-scheme.org/quick/
http://docs.plt-scheme.org/teachpack/image.html