About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 32. Chapters: Square kilometre, Acre, Square mile, Square metre, Barn, Hectare, History of measurement, Hide, Section, Tatami, Dunam, Morgen, Oxgang, Davoch, Romanian units of measurement, Jerib, Circular mil, Sokha, Pennyland, Perch, Bigha, Ounceland, Arpent, Stremma, Rood, Jugerum, Square foot, Kanal, Marla, Quinaria, Quarterland, Virgate, Tarangwa, Ngaan, Vergee, Markland, Toise, Pyeong, an, Rai, Square inch, Square yard, Ploughgate, Gunta, Rope, Tetrad, Carucate, Groatland, Feddan, Bunder, Nail, Cawnie, Pari, Marabba, Myriad, Kula, Lane meter, Hectad, Katha, Alqueire, Ankanam, Ground, Decimal, Lessa, Mansus, Dessiatin, Manzana. Excerpt: The hectare ( or; symbol ha) is a unit of area defined as 10,000 square metres (100 m by 100 m), and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare ('hecto-' + 'are') was thus 100 ares or 1/100 km. When the metric system was rationalised in 1960 with the introduction of the International System of Units (SI), international recognition of the are was withdrawn, though the hectare continued to be recognised as a "unit of measure that may be used with SI." The metric system of measure was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III (7 April 1795) defined five units of measure: Although the law defined the length of the metre, there was no practical way of accurately measuring the metre (and hence the are) until 1799 when the first standard metre was manufactured and adopted. The standard metre remained in the custody of successive French governments until 1875 when, under the Convention of the Metre, its supervision passed into international control under the auspices of the General Conference on Weights and Measures (GCPM). At...
