According to the U.S. Corps of Engineers, the shoreline of Beaver Lake is 487 miles long. The word mile, according to tradition, comes from the Latin word “millia” (thousand). Millia passuum, or one thousand paces, was a unit of length used by the Roman Legion . Every 1,000 paces the legion would push a stake into the ground to mark the distance marched. A pace is the distance from where your left foot leaves the ground to where it lands again when you are walking at a normal cadence. It takes two steps to make a pace. The Romans standardized the pace at 2 gradus. Each gradus was determined to be 2 ½ pedes. A pede was just under a foot long . Thus a passuum, or pace, was 2 ½ pedes of roughly 1 foot each times two pedes per passuum or roughly 5 feet. One millia passuum was then 1000 times 5 feet or 5,000 feet.
An illustration from Jules Verne’s novel “Twenty Thousand Leagues Under the Sea” (1866-69) drawn by George Roux.
Today’s statute mile is 5,280 feet, slightly longer than the Roman mile for several reasons. But, at 5’ 9 1/2”, the average American is slightly taller than the average Roman Legionnaire (approximately 5’ 7” ) so a mile is still close to 1000 paces. A walk around Beaver Lake’s shoreline then, if it could actually be walked, would be 487,000 paces or 974,000 steps. Currently, there is a fitness fad that sets a personal goal of taking at least 10,000 steps per day. If a person started walking around Beaver Lake’s shoreline taking the prescribed 10,000 steps per day, then they would finish the walk in approximately 3 ¼ months.
Infoplease.com claims the length of the Atlantic Coastline from Florida to Maine is 2,069 miles. That means walking 4 ¼ laps around the shoreline of Beaver Lake is the same distance as walking the eastern seaboard of the United States. But it really isn’t that simple. As it turns out, when measuring the distance of something like the shoreline of a lake, the distance is highly dependent on the length of your ruler . A shorter ruler measures more nooks and crannies than a longer one. Therefore, the length measured with a short ruler is longer than that which is measured with a long one. The length of the eastern seaboard was measured using a unit of 30 minutes of latitude, roughly 30 miles. The length of Beaver’s shoreline was measured using a much shorter ruler. Nevertheless, it is a long way around Beaver Lake.
Photo courtesy of Clifton Eoff.
When Beaver Lake is full to the brim, elevation 1130 msl (mean sea level), the surface area of the lake is 31,700 acres (Wikipedia). Frequently, you will hear or even read a reference to a “square acre.” The term “square acre” makes little sense. First of all, an acre is a unit of area itself, not one of length. An acre is an area consisting of 43,560 square feet. If you were to square an acre, then you would have 43,560 square feet times 43,560 square feet or 1,897,473,600 feet raised to the fourth power (when you square a square you get the fourth power). Feet to the fourth power are difficult to visualize, much less to lay out on the ground. Moreover, acres were never intended to be square to begin with.
Back in the Middle Ages in what is now England, the Anglo Saxons measured distance in rods, furlongs and miles. In our modern day system of measurement, a rod is equal to 16 ½ feet. To the Anglo Saxons, it was likely equal to the length of the pole used to control a team of 8 oxen . Or it may have been equal to the length of 20 “natural feet” or possibly 30 “shaftments” or hand-widths. A mile has already been described. A furlong referred to the distance that a man with an ox could pull a wooden plow (plow a furrow) before the ox had to rest. A furlong as it turns out was 40 rods.
Oxen are hard workers, but they apparently keep banker’s hours as it was considered bad form to work your ox both morning and afternoon. The Anglo Saxons determined that during a normal morning of plowing in good soil, an ox could plow an area one furlong long by four rods wide. That area that could be worked in a morning was referred to as an “acre” .
Thus, an acre is a long thin area one furlong long and four rods wide. Since the Middle Ages, the length of a furlong has been standardized at 660 feet and a rod at 16 ½ feet. Four rods are 16 ½ times 4 equals 66 feet long. So the area of an acre is 660 feet long times 66 feet wide equals 43,560 square feet. Today we refer to any parcel of land with an area of 43,560 square feet as being one acre in size regardless of the shape of the land.
Now getting back to the mile. A mile, as stated earlier, was a millia passuum or 1,000 paces of the Roman Legion. In 1592, the English Parliament standardized the mile at 8 furlongs, 5,280 feet (Russ Rowlett). Since the length of the mile was established by statute (law), we now have a “statute” mile.
While the units of furlong and rod are not frequently used these days, they are still around. Canoeists traveling in the Boundary Waters Canoe Area in Northern Minnesota quickly become familiar with rods. The Boundary Waters are hundreds, possibly thousands of lakes in the wilderness. When canoeists come to the end of one lake, they pick up their canoe and equipment and carry it all to the next lake. These carries are called “portages” and they are measured in rods. So you will see on the maps a portage of 80 rods or 320 rods etc. A portage of 320 rods is a mile long. Furlongs appear most frequently in horse racing. The Kentucky Derby for instance is run over a distance of one mile and two furlongs. Also, the home stretch is usually the last furlong of the race.
Furrows and rods show up other places as well. Those of us who took surveying in college were introduced to the “Gunter Chain.” The surveyors of the Louisiana Purchase used Gunter’s chain as they mapped out the land. The chain consisted of 100 links with each link being 7.92 inches in length making the total length of the chain 66 feet, or four rods. Now that might be handy for laying out 1-acre fields as the field would be 10 chains long by 1 chain wide. Every 10 links on the chain were marked with a ring. That means that each ring was 1/100 furlong and each link was 1/1000 furlong.
When cities were being laid out for the first time, they were typically divided up into standard city blocks with 16 blocks to a mile. So each block is ½ furlong long or maybe you prefer 5 chains.
So getting back to Beaver Lake. Our lake of 31,700 acres is equal to the area that a man with an ox could furrow in 31,700 mornings or roughly 87 years. That is more than a lifetime of plowing. The length of the shoreline is 487 miles. That could be expressed as 3,896 furlongs.
The length of Beaver from the headwaters down to the dam along the submerged river channel is 50 miles. But wait, that distance is measured over the water so it should be measured in “nautical miles” (6,076.12 feet) not statute miles. To save the pain of conversion, 50 statute miles is 43.45 nautical miles. Jules Verne’s Captain Nemo measured distance traveled under the sea by the Nautilus in “leagues.” A league is three nautical miles. That makes our lake 14.5 leagues long.