Ruler PNG Images
Although the metric system was introduced in the 18th century, researches have come across measuring instruments dating back to BC. The oldest measuring instrument in history is a
ruler made of copper alloy, invented by the German Eckhard Unger. This ruler dates from 2560 BC. It is also known that rulers made of ivory were used by the Indus Valley Civilization in 1500 BC. The first folding and flexible ruler was invented by AntonUllrich in 1902. The invention of the ruler provided a common perception of length in all countries.
-600x200_5b64753e.png "Measurement Transparent PNG - pngteam.com")
-500x500_49de5a8f.png "Vector Ruler Image - pngteam.com")
-489x510_64f6e4c2.png "Ruler Clipart Image PNG - pngteam.com")
-494x505_159923ef.png "Ruler Clip Art Transparent PNG - pngteam.com")
-912x161_f82d199e.png "Ruler Clipart Scale PNG - pngteam.com")
-495x504_1666d3b4.png "Ruler Measure Image PNG - pngteam.com")
