In the Footsteps of the Original Surveyor

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In the Footsteps of the Original Surveyor

When I first started working in the survey profession there were many new things I quickly learned. The two I heard the most were: dig the hole wider and deeper, and hold the dumb end of the chain. The LSI worked with was an excellent trainer and he made sure I became extremely skilled by having me look over his shoulder and always asking me a lot of questions.

My background had been a Manufacturing Engineer. One day we were in the field and he was doing some calculations before we started to search for the next corner. The math he was doing was very familiar to me so I asked what he was trying to figure out. He said he was computing the ?nverse?to next corner. To which I replied, ?ou mean the angle and the distance.? He looked up and said, ?o, the inverse. You?e a surveyor not an engineer.?r

At first I couldn? understand how he was finding these corners in middle of a fields and in the woods. Some of them, he told me had not been recovered for years. At first, I would tell myself, why don? we just walk around the swamp, it would be a lot easier. But all that time, in the office, he spent reading old notes soon started to make sense to me.

Original SurvSeveral years later I was working with a summer employee doing my own corner search. The two of us had walked about a mile into the woods to GPS a corner. He asked if I had ever been to this corner before and I said no. I lucked out and saw the plate on one of the trees as we got close. While we were checking the RP?, the summer worker asked if I smelled out the corner. I told him it was a great trainer that got us here.

Sometimes, when retracing an old survey, you need to find a way to correct your bearings to the original lines that were run. What I always did was find two original points that had a bearing recorded between them. I would take a new bearing and the difference found by subtracting one from the other. This difference can then be applied to the other lines, for which you have no original points, to reconstruct the direction and find more points.

Remember when retracing a survey: ALWAYS WALK IN THE FOOTSTEPS OF THE ORIGINAL SURVEYOR! This means that you must correct your chain and compass to his or her chain and compass, not theirs to yours. If the original surveyor did not record the declination that was used, it is possible to recreate it by using the annual change from the isogonic chart. Try to locate the chart that was in use at the time of the original survey and use the declination given.

If no trace of the original survey remains, use your best judgment to decide, but be sure to record in the notes what you used and the reason for doing so. Because if you don?, we both know it will come back and kick you in the rear.

Jim McLefresh

Jim McLefresh

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