Plumping Stations. 141 



Lake Haarlem, Holland. — This tract of land was originally 

 a large fresh-water lake, which it was supposed had been caused by 

 inundations in 15 91 and 1647, previous to which time it had been 

 an inhabited district with three villages. In shape it is an irregular 

 oblong, the length from north to south being 14^ miles, and the 

 greatest width eight miles. The total area contained 56,609 acres 

 of lowlands and meres, and formed the "boezem" or collecting 

 basin for the surrounding lands, being a portion of the great drainage 

 district of E.ijnland. The surface of the water in this boezem was 

 maintained at its lowest level by natural drainage, through sluices 

 emptying into the North Sea — one at Katwijk and the others into the 

 Y at Spaarndam, and at Halfweg. Schemes for the drainage of this 

 lake date back two and a half centuries. In 1643 Jan Adriansz — 

 surnamed Leeghwater — a millwright, published a detail plan for the 

 drainage, which passed through thirteen editions, the latest appearing 

 in 1838. In 1836 very severe storms occurred which drove the 

 water of the lake upon Amsterdam, and up to Leyden, submerging 

 part of the city and inundating 100,000 acres of polders. These 

 disasters finally decided the Dutch States-General in decreeing the 

 reclamation of the lake, and in 1839 a vote, amounting to over three- 

 quarters of a million of money, for the purpose was passed. It was 

 not, however, until nearly ten years afterwards that operations were 

 actually commenced. The first work was to surround the lake with 

 a dyke or bank to shut off the water from the adjoining polder. 

 Parallel with the bank a canal was cut called the Ringvart. The 

 dyke and canal were 37 miles long; the top of the dyke was 7 J feet 

 above A.P. — or 9 • 63 feet above ordinary high-water in the North 

 Sea— and the bottom of the canal, 19^ feet below A.P. The canal 

 was 140 feet wide, having a depth of 10 feet for a width of 95 feet, 

 and navigable for vessels. A road was made between the canal and 

 the dyke. The canal had slopes of two to one, and, with the cess, 

 occupied an area of 654^ acres. The dyke was made of peat, and 

 occupied, with its slopes, 1013J acres. 



A commission was appointed to determine as to the most suitable 

 machines for raising the water from the lake, and for afterwards 

 keeping it dry. The use of windmills, driving scoop wheels, or 

 Archimedean screw pumps, was strongly advocated, while the 

 advantage of steam was also pressed on the attention of the Com- 

 missioners. It was found after fully investigating all the proposals 

 that the estimated cost of draining the lake by wind-power would 



