armour training area

1) General subject: tank-training ground

2) Military: armor training area, armor training battlefield, armour training area, course, driving range, mounted course, tank park, tank test bed, tank training area, tank-driving range, tankodrome

SUBJECT AREA: Aerospace, Architecture and building, Horology, Weapons and armour

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Leonardo was the illegitimate son of a Florentine lawyer. His first sixteen years were spent with the lawyer's family in the rural surroundings of Vinci, which aroused in him a lifelong love of nature and an insatiable curiosity in it. He received little formal education but extended his knowledge through private reading. That gave him only a smattering of Latin, a deficiency that was to be a hindrance throughout his active life. At sixteen he was apprenticed in the studio of Andrea del Verrochio in Florence, where he received a training not only in art but in a wide variety of crafts and technical arts.

In 1482 Leonardo went to Milan, where he sought and obtained employment with Ludovico Sforza, later Duke of Milan, partly to sculpt a massive equestrian statue of Ludovico but the work never progressed beyond the full-scale model stage. He did, however, complete the painting which became known as the Virgin of the Rocks and in 1497 his greatest artistic achievement, The Last Supper, commissioned jointly by Ludovico and the friars of Santa Maria della Grazie and painted on the wall of the monastery's refectory. Leonardo was responsible for the court pageants and also devised a system of irrigation to supply water to the plains of Lombardy. In 1499 the French army entered Milan and deposed Leonardo's employer. Leonardo departed and, after a brief visit to Mantua, returned to Florence, where for a time he was employed as architect and engineer to Cesare Borgia, Duke of Romagna. Around 1504 he completed another celebrated work, the Mona Lisa.

In 1506 Leonardo began his second sojourn in Milan, this time in the service of King Louis XII of France, who appointed him "painter and engineer". In 1513 Leonardo left for Rome in the company of his pupil Francesco Melzi, but his time there was unproductive and he found himself out of touch with the younger artists active there, Michelangelo above all. In 1516 he accepted with relief an invitation from King François I of France to reside at the small château of St Cloux in the royal domain of Amboise. With the pension granted by François, Leonardo lived out his remaining years in tranquility at St Cloux.

Leonardo's career can hardly be regarded as a success or worthy of such a towering genius. For centuries he was known only for the handful of artistic works that he managed to complete and have survived more or less intact. His main activity remained hidden until the nineteenth and twentieth centuries, during which the contents of his notebooks were gradually revealed. It became evident that Leonardo was one of the greatest scientific investigators and inventors in the history of civilization. Throughout his working life he extended a searching curiosity over an extraordinarily wide range of subjects. The notes show careful investigation of questions of mechanical and civil engineering, such as power transmission by means of pulleys and also a form of chain belting. The notebooks record many devices, such as machines for grinding and polishing lenses, a lathe operated by treadle-crank, a rolling mill with conical rollers and a spinning machine with pinion and yard divider. Leonardo made an exhaustive study of the flight of birds, with a view to designing a flying machine, which obsessed him for many years.

Leonardo recorded his observations and conclusions, together with many ingenious inventions, on thousands of pages of manuscript notes, sketches and drawings. There are occasional indications that he had in mind the publication of portions of the notes in a coherent form, but he never diverted his energy into putting them in order; instead, he went on making notes. As a result, Leonardo's impact on the development of science and technology was virtually nil. Even if his notebooks had been copied and circulated, there were daunting impediments to their understanding. Leonardo was left-handed and wrote in mirror-writing: that is, in reverse from right to left. He also used his own abbreviations and no punctuation.

At his death Leonardo bequeathed his entire output of notes to his friend and companion Francesco Melzi, who kept them safe until his own death in 1570. Melzi left the collection in turn to his son Orazio, whose lack of interest in the arts and sciences resulted in a sad period of dispersal which endangered their survival, but in 1636 the bulk of them, in thirteen volumes, were assembled and donated to the Ambrosian Library in Milan. These include a large volume of notes and drawings compiled from the various portions of the notebooks and is now known as the Codex Atlanticus. There they stayed, forgotten and ignored, until 1796, when Napoleon's marauding army overran Italy and art and literary works, including the thirteen volumes of Leonardo's notebooks, were pillaged and taken to Paris. After the war in 1815, the French government agreed to return them but only the Codex Atlanticus found its way back to Milan; the rest remained in Paris. The appendix to one notebook, dealing with the flight of birds, was later regarded as of sufficient importance to stand on its own. Four small collections reached Britain at various times during the seventeenth and eighteenth centuries; of these, the volume in the Royal Collection at Windsor Castle is notable for its magnificent series of anatomical drawings. Other collections include the Codex Leicester and Codex Arundel in the British Museum in London, and the Madrid Codices in Spain.

Towards the end of the nineteenth century, Leonardo's true stature as scientist, engineer and inventor began to emerge, particularly with the publication of transcriptions and translations of his notebooks. The volumes in Paris appeared in 1881–97 and the Codex Atlanticus was published in Milan between 1894 and 1904.

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LRD / IMcN

SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering, Weapons and armour

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Little is known of the early training of Edward G. Parkhurst, but at the time of Civil War (1861–5) he was employed by the Savage Arms Company of Middletown, Connecticut. In 1869 he joined the Pratt \& Whitney Company of Hartford, Connecticut, as Assistant Superintendent and later took charge of their gun department. He was the inventor of many improvements in machine tools and armaments. Among these was an automatic rod feeder for turret lathes, in which movement of a single lever enabled bar stock to be fed through the lathe spindle and gripped by a collet chuck while the machine was in motion. This was patented in August 1871 and was followed by other patents, particularly for improvements in machine guns and their accessories. Parkhurst retired from Pratt \& Whitney c. 1895 but was afterwards associated with the American Ordnance Company and the Bethlehem Steel Company. He was a founder member of the American Society of Mechanical Engineers in 1880 and served his home city of Hartford as Councillor and Alderman. In 1900 he contributed to the journal American Machinist some articles of reminiscences dealing with the early history of the American machine-tool industry and, in particular, the earliest milling machines and the origin of the turret lathe.