Who taught the self-taught surveyors?
Blog by Emily Pierce, PLS, CFedS
It’s well-known that a number of our presidents were surveyors – Washington, Jefferson, Lincoln and even Roosevelt (kind of).
Did you ever wonder how the early surveyors learned how to survey? Many biographies say these men were “self-taught” . . . for Washington and Jefferson, this means they got a copy of “Geodaesia,” the first surveying book created for the New World surveyor.
Who wrote Geodaesia?
The map of the Carolinas created by John Love and Maurice Matthews published in London in 1711.
This essential reference was created by a surveyor, John Love. Love was born in England in about 1680, became a surveyor, then traveled to the New World to survey land grants in Jamaica and the Carolinas. He and his colleague Maurice Matthews created one of the early maps of the Carolinas.
While working in the Carolinas, Love observed the alarming lack of knowledge demonstrated by local surveyors and decided to create a practical reference book for field use to help those who didn’t have a background in mathematics and astronomy.
The first edition
In 1688, the first edition of “The Whole Art of Surveying and Measuring of Land Made Easie” was published in England. It became extremely popular because it took information from various disciplines arranged it in a way that was particularly useful to surveyors. It included geometrical definitions and problems, descriptions of instruments and their uses, various ways to take the plot of lands as well as how to use trigonometry in surveying. Instructions on how to use Gunter’s chain and measuring angles using the circumferentor (surveyor’s compass), plane table and semicircle were also included, along with many illustrations and useful tables.
John Love’s book was likely a part of every surveyor’s pack who left England for the Americas, and soon became the guide used throughout the New World.
This book was essential to laying out the boundaries in the United States. Each new edition included additional information and refinements, but it wasn’t until 1793, when the 12th edition “Geodaesia: or the Art of Surveying and Measuring Land Made Easy” was finally published in the United States.
George Washington learned the craft of surveying from the Eighth Edition published in 1768 in London. This book was in continual publication for more than a century which speaks to its practicality and usefulness.
Below are a few brief take-aways from the book.
Click the image to download the scanned copy from Google books.
A circumferentor circa 1770 - 1800, with excerpts from Geodaesia.
How to use the circumferentor
By sighting two different points from the same spot, such as the corner of a property, a surveyor could easily determine the intervening horizontal angle by addition or subtraction of the two recorded compass readings.
Gunter’s chain
This measurement tool is actually still being used today in rare instances. A full chain of 100 links is 66 English feet and also 20 European meters, so it was useful no matter what measurement system was being used.
Ideally, each link should measure 7.92 inches. Divisions along the chain are marked by the claw-shaped tallies (one to four toes), with notches indicating the number of ten-link sections; a round tally indicates the halfway point.
In the field, the chain is stretched out by chain bearers along a path or compass bearing specified by the surveyor, until it is straight. Then, the chain is pulled tight, and plumbed horizontal using a hand level and plumb bobs, and pins are set in the ground. The measurement is recorded, and the process is repeated again and again until the endpoint is reached.
When I was in college, I had the opportunity to pull steel tape along a small traverse of about five acres or so. It’s hard to imagine how challenging it must have been using the Gunter’s Chain and the other colonial tools in large, rugged, uninhabited tracts of land, like Washington and Jefferson and later, Lincoln did. I’m grateful for my total station!
The United States definitely owes a debt to John Love. We don’t know much about his life, but the book he wrote played a large part in laying the foundations of the system we still use today. Our early presidents relied on this book, so today’s a great day to remember John Love and Geodaesia.
Gunter's Chain, Library of Congress