History and Development
We know that for as long as history has been recorded there have been standards of length.
Early Babylonian and Egyptian records and the Bible tell us that length was first measured with the forearm, hand or finger and up until the 13th century European master builders carried their 'foot' with them from job to job. Many medieval towns had their measurement standard fixed to the town hall or gate.
As societies developed, measurement units became more complex. But with limited international trading different systems became established in different parts of the world.
The Metric System
The need for a single worldwide coordinated measurement system, was recognised over 300 years ago, but it wasn't until 1790 that the French Academy of Sciences developed the SI (System International) metric system to meet that need.
Adoption of the metric system by other nations happened steadily after France made its use compulsory in all its territories in 1840. In 1970 the UK adopted the metric system and is still in the process of changing over.
So what does this mean for us, looking at tape measures now?
Well, the vast majority of countries through out the world only recognise and use the metric system, so their tapes are only marked with metric gradations.
The UK and to some extent the USA continue to use both systems, so tapes manufactured for the UK market have to have both metric and Imperial markings.
The origin of the tape measure
No one knows who developed the modern spring return tape measure (pocket tape). The earliest record of a patent is in 1868 by an American named Alvin J. Yestin, but it states that that Yestin's tape measure was only an improvement of other poorly designed versions that we now have no record of.
In modern life tape measures are indispensable. Every homeowner or tradesman will posses at least one and possibly more for the vast range of measurement that goes on.
The Imperial (British) System
By the 18th century Great Britain had achieved more standardisation than other continental countries. The 'Imperial' units were well suited to commerce and trade because they had been developed primarily to serve commercial interests.
Through colonization and dominance of world trade during the 17th, 18th and 19th centuries, British Imperial measurements were established in many parts of the world, including the then American colonies.
It almost goes without saying that the total market for tape measures is enormous. The UK tape market alone is estimated to be in the region of £40m.