As I See It: Surveying is probably the most accurate of our technologies

We have controversies in Kona when a house seems to be too close to the property line. Once upon a time, I was a surveyor, everything from the location of a dog house to a big piece of land you may have heard of called it’s called Arizona. We helped make Google Earth possible.

Surveying is probably the most accurate of our technologies. Coast and Geodetic puts in control that is accurate to a fraction of an inch over hundreds of miles, about plus or minus one in a billion. Angles can be measured in degrees minutes, seconds and if necessary, fractions of a second. Accurate enough to enable NASA to aim a rocket confidently at targets a billion miles away. The vast distances do require mid-course corrections after thousands of miles.

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It wasn’t always like that. Old-time boundaries were based on landmarks. Property corners were usually something readily identified like a large oak tree or prominent boulder. Many boundaries were, and still are rivers. After all who can dispute a river, unless it meanders like the Mississippi-Missouri system. A boulder sounds specific, but did they mean the high point, or physical center? If land has eroded away unevenly the apparent physical center may have changed. Sometimes, bounds were even more vague “All that certain piece of land bounded on the North by Sister Susie, on the west by cousin Jake etc…” Distances were measured with a stick and angles by the sun at certain times of the year. When population was low and land sold for a dollar or a chicken an acre great precision was not needed. Needless to say, a lot of battles and even wars were fought over the interpretation of who owned what. Many boundary disputes were often settled in blood. More accurate techniques became needed.

Surveying in the city of Philadelphia was maddening because William Penn bought several surveyor’s chains (the 17th century 66-foot equivalent of a steel tape-measure) that were not accurate. They did not even match one another. To survey a property in Philly, the surveyor needs to learn a correction factor that depends on the neighborhood and which of the chains was used in 1690. George Washington used a transit with a magnetic compass to measure angles in rural Virginia plus or minus a degree, maybe.

In 1785, a methodical survey of western lands was begun to divide the land into uniform sections to aid settling and development without boundary disputes. It predated the Constitution. Boundaries had to be adjusted to fit square parcels on a spherical planet. This is why rural roads, jog left or right 50 feet occasionally for no apparent reason they follow the property lines. Urban land can be worth a million dollars a square meter, no wonder we go up 100 stories. At those prices, extreme accuracy is prized and the measurements have gone electronic to take out any human error.

The Hawaiians did not have access to precision instruments. But they had their own ways of preserving boundaries. Obviously, building a wall was one. One unique method was to roll a boulder downhill. No matter who did it the boulder would probably roll the same way and the border reestablished, unless, lava flow erased the channel the boulder would follow.

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Our surveyors today have access to incredibly accurate means. Locating a point to within a centimeter from one year to the next is quite practical. One problem remains; much of our beloved island is active volcano. It is a living thing, constantly changing often minutely sometimes grossly. Kilauea buries square miles, and creates new acres. Modern accurate survey can repeat the previous in terms of the map grids, but corners may not stay in the same relationship to buildings or other improvements. The distance between two points a mile apart can change a foot in a year. In the old days, the landmark ruled and measurements were to confirm, or help find it. Even then landmarks can be lost. In 1785, on the prairie with no landmarks a corner could be marked by burying a quart of charcoal. Imagine finding that a hundred years later.

Ken Obenski is a forensic engineer, now safety and freedom advocate in South Kona. Send feedback to obenskik@gmail.com