Just fyi, the most recent issue of Bicycle Quarterly has a nice set of articles on brake design, history, and performance: http://www.vintagebicyclepress.com/currentissue.html

Here's the table of contents:
BRAKE SPECIAL
• History: from wooden blocks to disc brakes
• Popular designs and oddballs
• Why they worked or didn't
• Which brakes to choose for your bike
• How to set them up correctly
• How to use them properly
• Tests of medium-reach dual-pivot brakes from Shimano, IRD/Tektro and Cane Creek

Note: I have no relationship with BQ outside of being a subscriber.