LAND DRAINAGE BY MEANS OF PUMPS. 5 
driving 10 screws and 5 wheels. These were later supplanted by 
two pairs of pumping stations, each having scoop wheels and cen- 
trifugal pumps, all driven by steam, by which means the drainage of 
the entire tract is now accomplished. 
The great Haarlem Lake of Holland is often referred to as the 
most remarkable pumping drainage project known. The total area 
of the tract, which is now surrounded by a canal 37 miles long, is 
41,648 acres, 3,011 of which are occupied by roads and main water- 
ways. The work of removing the water in this lake, which was 
originally 15 feet deep, was completed in 1852, after 39 months of 
pumping. It is kept drained by three pumping plants of 350 horse- 
power each, located at opposite sides and at one end of the great basin. 
The combined capacity of the three plants is nearly 2,000 tons of 
water per minute raised to a height of approximately 15 feet. The 
area which was formerly a lake is now traversed by well-improved 
highways and is occupied by about 20,000 people. 
In September, 1913, the Dutch Government authorized the under- 
taking of a much greater project. It is planned to dike off about 
1,000,000 acres of the southerly portion of the Zuider Zee. A little 
over one-half million acres will be completely reclaimed and made 
suitable for the production of crops, the remainder will form a reser- 
voir for the discharge of the River Yssel while the tide gates into the 
untouched portion of the Zee are closed. The work, as planned, will 
consume 33 years in the construction and will require an appropria- 
tion of $130,000,000. The annual revenue from the cultivation of 
these lands is estimated at $28,000,000 and the population it will 
support at 300,000. Fifteen steam pumping plants with a combined 
horsepower of 17,000 will lift the water out of the various divisions of 
the main district. 
The drainage of large portions of the fenlands in eastern England 
was originally accomplished by means of scoop wheels operated by 
windmills. It was not an uncommon occurrence for the districts to 
be inundated because of the failure of the pumps to operate when 
required to remove the water. Losses from this cause became so 
great that the several plants were gradually equipped with steam 
power, which rendered the drainage of the land much more certain 
than under the old system. 
W. H. Wheeler, in his History of the Fens of South Lincolnshire, 
states that the entire fens known by that name cover about 363,000 
acres, that about 85,000 acres are from 6 to 12 feet below high-water 
level, and that 124,600 acres of this area are drained by steam power. 
The pump originally used was the large scoop wheel still operated in 
many of the plants, but the centrifugal pump is gradually being 
introduced as being better suited to the conditions now prevailing. 
The same author, in his book entitled "The Drainage of Fens and 
