In February of 1998, the department commissioned a design for an ``official departmental coffee mug''. The mug has the University Crest on one side, and on the other side, this picture.
Here is an explanation of how the picture was generated from the Lambert W function.
HTML version (generated by TeX2HTML)
compressed postscript version
The explanation is only two pages long, but the postscript version of the picture takes almost two megabytes, and so you wouldn't want to download it. The compressed version, above, takes only about 280K. You can use uncompress (on Unix) or WinZip (on Windows NT or whatever) to decompress it.