Jan Leeghwater
January Adriaanszoon Leeghwater (* 1575 in De Rijp, Netherlands when Jan Adriaanszoon, † 1650 in Amsterdam) was a Dutch engineer, mills and wind pumps designer and architect. His pioneering work was the draining of the great lake of Beemster ( Ndl Beemstermeer ) at the beginning of the 17th century. He is considered the inventor of the rotary mill cap ( see Dutch Mill). Leeghwater came from a poor peasant family and was a skilled carpenter. His knowledge in the fields of mechanics, hydraulic engineering and engineering and the languages he had almost all self-taught.
The drainage of the Beemstersees was one of the largest projects ever completed in this area and agricultural land use area of the Netherlands added 6880 acres. Land is for the relatively small nation of the Dutch, whose land was won in large part from the low marshes of the European west coast, is of particular importance. For centuries, had the nature reclaimed areas, the so-called polder, to be defended against the sea, lakes or swamps from which repeatedly tried to assert themselves. Since the Netherlands is one of the most intensively developed countries in the world, constantly new enclosure is needed - it has not changed since Leeghwater.
The ambitious and expensive project arose when a group of directors of the Dutch East India Company was looking for investment opportunities for the wealth acquired in the Far East. The project was advertised and more candidates submitted offers until finally, on April 10, 1608 was awarded the contract Leeghwater. The contract stipulated that the ring dike should be completed on 1 November 1609. 26 water mills were erected at certain intervals in order to pump the water for the 38 km long ring dyke. The work was only a short time after the scheduled date completed, but a month later a violent winter storm broke a dike and destroyed it in half. The work was immediately taken up again and within three years was started with the agricultural use of the polder. Soon the income of the fertile soil had covered the cost of construction.
After the successful drainage of Beemstersees Leeghwater was a busy man. He got the drainage of more than 30 lakes and marshes: Heerhugowaard ( 1625), Purmer ( 1622), Schermer ( 1635), Star Ocean and De Wormer ( 1626 ). He went to the draining of the marshes in Bordeaux ( 1628) and Metz ( 1630). In Schleswig -Holstein, he was able to close the Bottschlotter low of Dagebüll ( 1633).
He also had a part in the conquest of the fortress ' s- Hertogenbosch in 1629, which was considered impregnable because of the surrounding swampy terrain. Leeghwater headed by two rivers and drained the morass with pumps that were driven by windmills, so that the city could be taken within four months. Leeghwater was a versatile person interested. He designed and built furniture, drew sketches and made sculptures in wood, stone, ivory and metal. He also built bridges and spiers, including the Westkerk and the Zuiderkerk in Amsterdam, both of which he endowed with bells. However, it was not possible Leeghwater to realize his ambitious plan. He wanted to drain the constantly growing Haarlem lake, why would they have according to his calculations require not less than 160 driven by windmills water pumps. This project, which is not mastered his successors, could be realized only with the help of modern engineering and the steam pumping stations of the 19th century. Previously Leeghwater had brought the traditional Dutch system of drainage of the polders to new heights, which is why it deserves a place among the best engineers in history.