In order to overcome the limitations of senses and body parts, and to bring about a worldwide uniformity in the measurement system, the need for exact measurement was felt. For this, a standard of measurements had to be developed which everybody everywhere accepts.
The problem of measuring lengths exactly was first solved by the Egyptians in 3000B.C. They did this by inventing the standard cubit. They realized that the length of the arm actually did not matter as long as people of Egypt were concerned. Then they made measuring sticks exactly of the same length as that of standard cubit. In this way they made sure that the cubit was the same length all over Egypt. That is really how measurement is carried out today. In fact, for each measurement a standard is chosen. Every measuring instrument has to be compared with that standard. The present measurement system, which is accepted world-over, has its origin in the French Revolution. You will study the details of the modern system of measurement, in the following sections.