Re: Happy 40th Birthday, HP35 Message #8 Posted by Nick R on 5 Jan 2012, 11:52 a.m., in response to message #7 by db (martinez, ca.)
Your comments on surveying field work took me back to when I was working as a chainman in the 1970s. The minimum closing accuracy required legally on traverses was one in 5000, but our employers expected one in 10,000. Anything less than this meant we'd be sent back out to find the error. Distances were measured with a 200 foot steel tape pulled taught against the string of a suspended plumb bob. By today's standards, we chainman would be considered unskilled laborers, as most of the day's work consisted of cutting line with axes, but we very rarely failed to achieve the company's goal of accuracy. I'd like to think this was due to us taking pride in our work, but the reality was none of us wanted to go back and re-run an unsatisfactory traverse. Everything is now electronic, and the reflectng prism has replaced the plumb bob held by a scruffy individual standing in a swamp surrounded by mosquitoes as his boots fill with water. Measuring a distance across a river is done in a fraction of a second with a laser beam. We did the same thing a lot slower by tying the end of the steel tape to a dog and persuading him to swim across for a biscuit. Steel tapes did have one advantage, however. While working near an electric fence I was able to throw my end of it onto the wire and shock the instrument man who was holding the other end.
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