Today, automobiles, factories, smartphones, healthcare and other aspects of modern life require a myriad of sensors. In ancient times, builders, seafarers, farmers and astronomers required measurements to create the pyramids, navigate the Mediterranean Sea and observe celestial alignments and occurrences for planting and other purposes. Also, trade required measurements to ensure fair exchange within each culture and between different cultures.
Constructing huge stone buildings, like the pyramids, required extremely level ground, precise right angles and consistent length measurements. Egyptians used a part of the human anatomy to define the first unit of measurement -the cubit. The cubit was the length of the arm from the elbow to the tip of the middle finger (about 18 inches).
Before bubble levels, the ancient Egyptians used a simple A-frame structure with a string hanging down from the center of the “A”. Called a plummet or plumb bob, a weight at the end of the string would move the string in one direction if the A-frame level was placed on an uneven surface. Markings on the crossbeam of the “A” indicated how far off center the measured surface was.
Image source: Ancient Egyptian Survey Tools – DT Online
The earliest time measurements in Egypt and civilizations circa 2000 BCE+ employed sundials – fixed pointing devices that indicated the passage of time based on the location of the sun and the shadow cast on the ground. Later, in Roman Times, the water clock and hourglass were used to measure time.
For traders to ensure a fair exchange, an equal-arm balance with a beam supported in the center and pans hung from the ends by cords showed buyers and sellers that the proper quantities were being exchanged has been used for at least 7,000 years.
Weathervanes appear to be one of the “newer” ancient measurements. Attributed to the Greeks as early as the first century B.C., Andronicus in Athens mounted a bronze sculpture instrument at the top of the Tower of the Winds.