In addition to working with my wonderful friends and Indium Corp and teaching statistics and manufacturing process courses at Dartmouth, I have recently taught a course on the impact of materials on civilization. This course is intended for non engineering majors and fulfills a technology requirement at Dartmouth. One of the resoruces for the course is a book written by my friend, Professor Steve Sass of Cornell. The book is entitled: Materials: The Substance of Civilization.
For part of the course we study the invention of the bow and arrow and how the development of the English Longbow in the 14th century affected warfare for 200 years. Around the time of Robin Hood (the 12th century), the pull strengh of bows was 50 to 60 pounds. With these types of bows, arrows did not have enough energy to penetrate a knight's armor. The English longbow require 80 to 120 pounds to pull it back. Arrows shot from one of these bows could kill a knight in armor. These bows were first used by the English in the battle of Crecy (France) on August 24, 1346. The English were greatly out numbered, but they slaughtered the French. The 11,000 English archers filled the sky with arrows before the French could get within range with their crossbows.
The 80 to 120 pounds of pull strength was so great that it typically took 3 years to make an archer strong enough to pull the bows back. As a teenager, I was an archer of modest competency. I was curious to see if I could pull back one of these strong bows. I found a Bowyer (bow maker) in British Columbia that made a 90-100 pound longbow for me. Here is a photo of me pulling it back with ease! This has really been great for my morale as some of my football player students cannot do as well. (Some people think the best part of this photo is that you can't see my face!)