Conventional Methods of Measurements
Taking measurements is one of the most common tasks we come across in our day-to-day life.Be it cooking, where measured amount of ingredients are added in order to cook food properly; purchasing items and artifacts, so that fixed amount can be allocated to certain object or quantity; in medicines, where a fixed dosage is required to treat a particular disease; sports, so as to decide the winner among the participants etc. Today, we follow standard unit of measurements for volume, mass, length and time. But ever wondered how these measurements were taken when such units were not introduced.
Historically, human body was used to provide the basis for units of length
- Inch: Inch is the measure of thumb, which was used to measure the length of items small in size, for example, seam of a cloth, length of paper etc.
- Foot: Foot is the measure of length typically defined as 15.3 % of the height of a human body with an average height of 160 cm. This unit differed from place to place and trade to trade. This unit was preferred by Roman and Greeks and was typically used to calculate the size of a piece of cloth, height of human beings and cattle, size of a building etc.
- Cubit: Cubit is the unit of measurement of length based of the length of forearm, typically the tip of the middle finger to the elbow bottom. This unit of measurement was preferred by Egyptians and Mesopotamians. Cubit rods have been discovered in the remains of the ancient Egyptian civilization. These rods are usually 20 inches in length, which are divided into seven palms; each palm is further divided into four fingers which are further subdivided.
- Yard: Yard is the unit of distance typically based on human paces. A yard is typically equivalent to two cubits or three feet, which is approximately 36 inches.
- Miles: A mile is equivalent to a thousand paces, where pace is equal to two steps, such that the walker is back to the same foot.
A foot comprises 12 inches and three feet comprise a yard. With measurements such as these, it was easy to explain how far the next village was and to find out whether an object will get through a doorway.
These measurements also helped the people exchanges clothes and wood in a barter system.
- The grains of wheat were used as a measure of weight due to their approximate standard size. The number of grains of wheat was taken as a standard, which even now is used by some jewelers. One grain is equal to 64.79891 milligrams.
- A measured length of metal used to be kept in the town centre or the temples and copies of the same were distributed among the people of that community. This metal lump was considered as a standard of weight.
- Sundial: The movement of the sun in the sky was one of the measures to estimate time, which was done on the basis of length and position of shadow cast by a vertical stick. Later, the marks were made where the suns shadow fell, which gave an approximate measure of time of the day in a consistent manner. The device came on to be called as a sundial
- Water Clock: The water clock was used to measure time on the basis of the amount of water dripping from a tank. This method was not considered reliable because the flow of water is difficult to be controlled. The device was termed as Clepsydra.
- Hour Glass: The hourglass works on the same principle as a water clock, using sand instead of water. It is still found in some places, in a reduced form.