Many countries have adopted or developed measurement units on their own throughout the ages. Many have gone on different directions, each having a means to measure according to their own needs. Some have imported the measurement units, and adapted them to their local environment.

For example, during ancient days, horses were used for pulling machines. Probably at that time, their muscles were the most powerful available. That was before the dawn of the steam engines. Horsepower was adopted as a unit of measurement. Never mind about uniformity. Who knows, maybe, all the horses had the same built, age or strength. Well that's the standard they adopted.

The British had spread their influence to many parts of the world during the height of the British Empire. The adoption of the British method of measurement naturally follows in many of the colonial countries. The French who developed a different set of measurement units had also influenced many other countries.

The US whose early descendants came mainly from UK had naturally adopted the British way of measurement as the base. However, just as the spellings in the English language undergo some changes; the measurement units too began to evolve to become an entity on its own. So we have US gallon which represents a different volume than the Imperial gallon. Overall, the US measurement units have not changed much from the British units, although there are other standards like pipe and machine threads that have evolved.

Nowhere is it more noticeable when we talk about measurement, than the difference between the metric measurement systems and the Imperial systems.

The metric system revolves around the multiples of 10 for all the measurement. Thus, all the measurement units have the same name. For example for length measurement, it is the meter (metre). Whether it is called kilometer, meter, millimeter, or centimeter, the measurement of length remains the same. For weight, it is the gram. Thus we have microgram, decigram, nanogram, etc.

The imperial systems do not have a standard way of measurement. We have 12 inches to a foot, 3 feet to a yard, 10 square chains to an acre, 778.3 foot-pounds to a Btu, 22 yards to a chain, and many other means of measurement that is extremely difficult to remember.

In today's modern times, although we know that many of these units no longer describes the correct relationships or are clearly outdated, still we need to continue using them. The reason - many generations of the citizens of a country has built their lives on these measurement units. Textbooks, machinery, buildings, institutions, schools, and the whole education system were geared towards using the same measurement units that the forefathers of that country had used. It's no easy task to change all these.

Sometimes it is national pride. Who will want to admit that the whole nation has been using a "wrong" way of measurement? "We have built advanced space vehicles using the same measurement units that our forefathers have used, why do we have to adopt another nation's units?"

Let me accurately clarify - "wrong" here does not mean incorrect. It just means that there is a better way, the International System - SI or "Systeme Internationale". This system was set up in 1960 by an International Committee to establish rules to decide on a set of standards for the fundamental quantities used in the sciences so that everybody can use the same units and avoid confusion.

Currently, we are now in another century. Trade and businesses between countries have gone global. Engineers have found themselves working in the far reaches of the world, where the measurement units are different from their home country. Somehow, they have to get to know the ways of measurement that is foreign to them, whether they like it or not.

Well, if you cannot beat them, join them! Get to know them! Get to know how to convert to the units that you are familiar with. Check out the conversion factors at http://www.free-engineering.com/searchdata.htm . It's just a finger reach away from the topsy-turvy, melting pot world of measurement units. That's how to make sense!