I worked as a survey crewman back in the mid 70's and often found that I had to amuse myself at times when the crewchief spread out the project plans on the pickup hood for thirty minutes to an hour.

One time I decided to make a "David and Goliath" sling shot.... the real deal with the leather pocket strung between two leather thongs. Twirl it around your head and cut it loose. I was pretty excited about it and got the chief to let me try it out, next time we were where I could get some nice round river stones.

Anyway he and the other guy on the crew stood behind me about 20' and I wound it up and cut 'er loose. They said the stone had a nice "hummm" on it... as it went right between them - about head height.

R&D pretty much stopped on that project at that point.