Pattern nº3 of the Metric System

This steel bar shows the exact length of a meter. Its scale has increments of 10, with each decimeter divided into centimeters, and the first 10 into millimeters.

This piece's origins hold particular significance. It was brought to Spain by Spanish mathematician Gabriel Ciscar y Ciscar who, together with Agustín de Pedrayes, was part of the Spanish committee involved in the Paris Weights and Measures Commission in 1798. The commission followed its 1791 counterpart set up by the Paris Academy of Sciences to undertake studies to determine units of measurement. Its work and meetings led to the development of the decimal metric system. This system created a method for precise and standardized measurement, overcoming all the issues generated by previous systems.

It was made by Frenchman Esteban Lenoir, an artisan scientific instrument maker famous for his work on a range of French endeavors. These included the measurements taken of the meridian arc that runs through France by French mathematicians Jean-Baptiste Joseph Delambre and Pierre Méchain, the results of which helped to create the metric system. Lenoir also made scientific instruments that were taken on Napoleon's expedition to Egypt.