Protractor lying on top of paper
Protractor lying on top of paper

Measurement tools have a long history, which reaches all the way back to ancient times. Interesting enough, many of these tools have changed very little over the years and are still in use today as part of modern day society. Archaeologists have uncovered many simple measurement tools along with units of measurement used by ancient societies.

Protractor

Protractors, which are semi-circular measurement tools, were used in ancient times to measure angles between two intersecting lines. There is little difference between what they looked like then and now. The semi-circular tool is marked with angle measurements from 0 to 180 degrees. Protractors first were identified as being used in the 1600s. Protractors were first used as navigation tools to measure angles that were used on nautical charts but quickly became popular as a construction tool, too.

Sextant

A sextant is a navigational tool used by sailors to determine the position line on a navigational chart. Basically, an angular measurement is taken between a celestial object, like a star, and the horizon line. It is an excessively precise instrument. The principle behind the sextant was first developed by Sir Isaac Newton and then later developed into the sextant during the 1700s. The 60 degree span of the navigational instrument gives it its name. Sailors still use this instrument today as a back-up to more modern GPS systems.

Barometer

A barometer is used to measure atmospheric pressure. Used since the 1600s, the first barometer involved a vacuum tube of glass placed on top of a container of mercury. As the air pressure dropped, the mercury would rise in the tube, indicating the expectation of rain. The barometer is still used in meteorology today as a viable indicator of the weather and as a tool to measure atmospheric pressure accurately.

Sundial

This first known measurement of time was the precursor to the modern day analog clock. This measurement tool appears in history as early as 3000 BCE. Simply by driving a straight stick into the ground and measuring the shadow cast by the sun, allowed ancient man the ability to tell time throughout the daylight hours. Though the use of sundials has become obsolete, sundials are still found throughout the world as decorative elements in gardens and in historical monuments where ancient societies once used them.

Thermometer

Though the thermometer was first actively used during the 1700s as a measurement of temperature when the first scale was added to the instrument, as early as the first century BCE, the ancient Greeks used a measurement device similar to the modern day thermometer. In fact, Galileo is credited with the invention of the thermometer. Mercury has proven to be the most accurate material used to indicate temperature in a thermometer. A variety of other colored liquids have been used to measure temperature using a thermometer.