I think you missed my point, Thomas. I wasn't saying it just about a foot or any of the other English units. The same could be said about the metric system. How did the first person KNOW it was a gram? milligram? meter? millimeter? And the cubit....how did we figure out how long a cubit is? I mean, Noah was to build the ark so many cubits high, etc. I'm guessing he used his arm as the basis for the measurement. So, if a cubit was the length of Noah's forearm back then, and then someone else had to build something else using the cubit measurement, how did they do it? They didn't have Noah's bone to measure against, so they had to use their own arms. So, the measurememt would actually change as time went on......Where can I find out how this was all figured out? Now I am confused as well..... See what happens when I think about math stuff? My brain hurts!