Printed chart in various colours on paper. It has varnished wooden rods at the top and bottom which enabled it to be rolled up when not on display. The rod at the top has a four-sided section while the one at the bottom is circular. Using explanatory drawings and names, the chart presents measurements of area, volume and capacity, with vessels for measuring sand, and liquids and special measures for oil. The chart also shows iron and brass weights, a set of weights and various types of scales (Roman scales, balance scales, hand scales, column scales and special scales for weighing paper or letters). The chart is completed with various kinds of measuring devices (a metre ruler, a ten metre measuring tape, a try square) and a thermometer. At the bottom there is also a set of silver, bronze and gold coins.
In 1849 the Decimal Metric System was introduced into Spain by law. From 1852 teaching the legal system of weights and measures became a compulsory part of primary education, and the best means of spreading its use. The Moyano Law of 1857 stipulated the different subjects to be studied in Primary Elementary Education. One of these was called “Principles of Arithmetic”, a subject that included the legal system of weights, measures and coins, so enshrining the principles set out in the Law of 1852. This helps explain why such great efforts were made in this area in those early days. These were later followed by an increasing profusion of publications and teaching materials to help present this subject in class. Bibl.: Museo Pedagóxico de Galicia (2013), A pedagoxía intuitiva. As láminas educativas, Santiago: Consellería de Cultura, Educación e O.U., Xunta de Galicia, 12.