(Excerpts from an article by Alanna Mitchell in The New York Times)
Did you know that America has two feet? And did you know that we’re about to lose one of them? The first foot is the U.S Survey Foot that was established in 1893. The second foot is the newer, and slightly shorter, International Foot. The difference between these two competing feet equates to about 1/10 of an inch (0.12672 inches) per mile. If you expand that difference over one million feet, it will add up to about 2 feet.
“So what’s the big deal? My property is only 300 feet long. Why should it matter which foot I use?” you ask. True, for most people, it doesn’t matter which unit of measure you use. But for land surveyors, it’s a big deal! The reason is that thanks to Global Positioning Systems (GPS), much of our work is done in the State Plane Coordinate System. An example of a State Plane Coordinate in Delaware County is:
(North 224,620.1652, East 2,636,763.4972)
If we don’t use the correct foot unit at this distance, we could find ourselves 5 feet from our intended position!
Many states, like Pennsylvania, use the U.S Survey Foot for their measurements. Other states, like Arizona, use the International Foot. Julianna P. Blackwell of the National Geodetic Survey recognizes this conundrum, especially now that geodesists are in the process of recalibrating the National Spatial Reference System. The decision has been made to do away with the old U.S Survey Foot and have all states convert to the International Foot by January 1, 2023.
Fun Facts:
The colonization of America brought a plethora of units of measurement, as settlers brought their measurements from their own countries. These included the English ell for cloth but also the far shorter Dutch ell, the Rhineland rod and the British chain and the Spanish vara for measuring land, the English flitch of bacon and hattock of grain, plus the German quentchen for gold. By the time we declared our independence, America had 100,000 units of measure.
George Washington (one of my favorite land surveyors) in his very first message to Congress in 1790, suggested establishing a standard of weights and measurements. He proposed using elements of the British Imperial System, including the yard.
“So how long is a yard?” That’s simple: Four grains of barley make a finger, four fingers a hand, four hands a foot, 16 fingers per foot became 12 inches and were tripled to make the yard.
Rest assured that, regardless of where your project lies, if you come to Howell Kline Surveying & D.L. Howell Engineering, we will get you started on the right foot!
