Xerox machines and Brownies

Cecil's Columns/Staff Reports
1

In the 1977 Cecil Adams article prominently displayed today, http://www.straightdope.com/classics/a1_235a.html, ol’ Unca Cece quips:

I assume the kind of “Brownie” being referenced here is not:[list=A][li]the fudge-based cakelike treat baked in a square pan,[/li][li]the mythical fairy-like forest creature, or[/li]some kind of slang for the Browning automatic rifle.[/list]If so, what kind of a “Brownie” is it?

2

Drat. It looks like someone else already started up a thread here on this very topic:

http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=212809.