"Swingman" wrote in message
...
On 11/23/2013 7:24 AM, Jim Wilkins wrote:

If you can visualize the part you want to make, a pencil is all you
need to capture it. The designers of this didn't need no stinkin
CAD:
http://www.paradoxplace.com/Photo%20...0Cathedral.htm

Obviously not, but with CAD it might not have taken 56 years to
build either.


Their problem wasn't just drafting, they didn't know how to combine
lateral thrust vectors on the columns.
http://en.wikipedia.org/wiki/Simon_Stevin
http://www.britannica.com/EBchecked/...4/Simon-Stevin

jsw