Wikipedia on the Cutter Expansive Classification system and its creator Charles Ammi Cutter.

Google Books:

Rules for a Dictionary Catalog
How to Get Books, with an explanation of the new way of marking books (1882)

The schedules aren't scanned yet, I think. More later, after coffee.

Letter: Cutter on changing the letters in his classification to numbers.

You might also try:

http://www.bostonathenaeum.org/cuttergui...

and

http://www.forbeslibrary.org/books/cutte...

For very quick outlines of Cutter Classification as used by these two libraries

You have to be careful what you mean when you talk about "Cutter Classification." The system used at the Boston Athenaeum is a classification system designed by Cutter, but it is not the Cutter Expansive Classification system. It is little more than a prototype where he worked out his ideas long before the first schedules of the Expansive Classification were published.

And as for the wikipedia article, it has its problems as well. Until it is corrected I'd recommend looking elsewhere.

Yeah, I know. That's really the whole problem with Cutter. Even among the libraries that used it, there was no central organization, so there's basically one system per library now.

I recently wrote a paper for a class on this very topic. I've put up an html version:

http://web.simmons.edu/~kalish2/cutter/o...

I read the Conrad paper, and had a long talk with him about it.