The Difference Engine - Possible Spoilers

Just finished and loved the book but can someone please explain what the mathematical McGuffin was that Lady Ada wrote and which buggered up the Napoleon and why that lead to the last two pages - especially since Oliphant seemed to have prevented the triumph of the Bad Party?

The world building was lovely but the McGuffin defeated me.

It's been a very long while since I read it, so I couldn't tell you from personal reading/experience, but this might be of help (spoilers btw):
http://ask.metafilter.com/10737/What-is-going-on-in-the-last-chapter-of-Gibson-S...

thank you, that was exactly what I wanted to know.