zoser, on 08 December 2012 - 08:55 AM, said:
On the other hand there is this:
Now look how perfect it is and tell me in all honesty if that could have been done by spinning a copper tube back and forth with a bow using sand while some poor soul holds it erect while applying weight. I tell you know way.
I think you are envisioning something similar to a Boy Scout starting a fire with a bow and stick.
There may not have been a poor soul holding a large stone on top of the pipe. I picture more of a scaffold with a stone which can traverse vertically as the drill deepens the hole.
Also, two large bows, one of each side of the pipe, each with a man on either end. Four men, lots of sweat, equals lots of power in that configuration.
Another possibility is a pump drill, scaled up for the task, which is described about half-way down this page. This could be modified to include being bow powered:
http://en.wikipedia.org/wiki/Bow_drill
Edited by synchronomy, 08 December 2012 - 04:55 PM.
At the heart of science is an essential balance between two seemingly contradictory attitudes--an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new.
This is how deep truths are winnowed from deep nonsense. -- Carl Sagan