Religion is at the forefront of the founding documents of many nations. Some, like Iran, Saudi Arabia and Costa Rica, are unapologetically theocratic. They explicitly announce the role of religion as a co-equal to secular sovereignty. Others, like Canada and Poland, acknowledge the role of God in their preambles but then eschew religion later in …
Continue reading “America is not and shall never be a Christian Nation!”
Surveyors’ range poles have been used for millennia to mark station positions, align straight lines, and provide visible targets for sight lines. Range poles are painted with alternating, high-contrast bands (such as red and white, red and yellow, or black and white) to ensure proper visibility across long distances or during inclement weather. These bands …
A theodolite is a precision optical instrument for measuring angles between designated visible points. Unlike the circumferentor which can only take measurements in the plane, the theodolite can take bearings in both the horizontal and vertical planes. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide …
A circumferentor, or surveyor’s compass, is used to measure horizontal or magnetic bearings for lines laid out in a survey. It consists of a box containing a magnetic needle, which moves freely over compass rose divided into 360 degrees and a pair of sights located on the North-South axis of the compass. Circumferentors were typically …
Continue reading “Tools of the Surveyor — The Surveyors’ Compass or Circumferentor”
Before we had sextants and octants, celestial navigation was accomplished using the astrolabe. Originating in Greece and perfected by medieval Islamic scholars, this astronomical “multi-tool” and rudimentary analog computer revolutionized navigation, timekeeping, and astronomy before being replaced by the sextant and pendulum clock. Want to have the Regimental Brewmeister at your site or event? You …
The sector is a hinged calculating tool used by navigators, draftsmen, and woodworkers to solve problems using proportions and the rules of similar triangles. It consists of two rulers joined by a hinge. By opening the hinge at different widths, the user can use dividers to solve proportions, scale dimensions up or down, and compute …
Continue reading “Tools of the Surveyor — The Sextant and the Octant”
In 1730 Thomas Godfrey of Philadelphia invented what was referred to as a double reflecting sextant. At the same time, entirely independent of Godfrey, John Hadley, an English mathematician and astronomer, invented the Hadley’s Quadrant which was also a double reflecting. Both instruments were equipped with half mirrors and sights. Latitude measurements were taken by …
Continue reading “Tools of the Surveyor — The Sextant and the Octant”
An alidade is a device that allows one to sight a distant object and use the line of sight to perform a task, like recording a line on a map. These devices are often incorporated into other tools like the surveyor’s compass or circumferentor but can also be used independently on the plane table. The …
Developed by Edmund Gunter in 1620, Gunter’s chain sought to reconcile traditional English land measurements, based on the number 4, with the decimal system. Each chain was composed of 100 links, measuring 66 feet total (each link measures 7.92 inches long). A chain is subdivided into four parts—each made up of 25 links measuring 5 …
A surveyor’s artificial horizon is a device developed by London instrument maker John Elton in 1732, this tool (traditionally a tray of mercury but this can be oil, water, or a specialized mirror) allows “for taking altitudes without a horizon.” With the artificial horizon, precise latitude readings may be taken with a sextant when a …
Continue reading “Tools of the Surveyor — The Artificial Horizon”
Michael Carver -- Historical Interpreter/Reenactor 