The Haarlem Meer was formed in the teenth and seventeenth centuries by the junction of several small lakes. There villages Were '0V ered with water, the last in 1647. and much otherwise valuable territory was rendered u-.less. it the various early plan. for relief, one pro posed by Leeghwa ter, in 1643, contemplated an embankment around the whole area, and IGO windmill-driven pumps, with an estimated cost of about $1,500.000. In 1835 the Meer was extended still further, and in 1S:37 work was be tor the reclamation of 44,724 acres of land, revered with some thirteen feet of water. An embank 111411t 37?•-. mile- long was built around the lake, and a canal then in existence was improved and extended, partly for naviga tion. It was decided to use steam-pow•r for pumping. and a pumping-engine was adopted of the single-acting type. It had a high-pressure cylinder inside the low-pressure (Inc. and a cross-head coupled to eleven beams; on the outer end of each was a single-acting pump. These pumps were arranged in a circle. The first en gine had a high-pressure cylinder of inches diameter: low-pressure, 144 i n inches. The pump cylinders were 63 inches in diameter. The stroke of both the steam and pump cylinders was 10 feet. The beams were 32 feet 10 inches long. Each of the five boilers was 6 feet in diameter. and 30 feet long, with a single 4-foot fine. There were three engines in all, the last two to be erected being similar to the one de seribed. but having a 73-ineh pump cylinder.
The first engine lowered the lake six inches in about ten months, after which it took the three engine- 39 mouths to complete the work. For the six years ending about )S44, the first, or Leyden engine, ran at an average speed of strokes per minute, diseharging 238 long tons of water per minute. At the close of that period this pumping-engine was replaced by a centrifugal pump. having a 58-inch inlet, and driven by an inverted direct-acting compound engine, designed to run at 100 revolutions per minute, and to give 550 indicated horse-power. On a trial. this plant, with the engine running at 90.9 revolutions per minute, and with a lift of 14.97 feet, delivered 293 long tons of water per minute for some hours: the maximum for one hour being 342 tons, lifted 15.34 feet.
With the exception of Holland, the Fenland of England is a region where the -ciente of drainage has probably been applied to the improvement of land on a larger scale than in any other part of the world. The district known as The Fens is a tract of flat and marshy land on the east coast of England. having an area of about 400,000 acres. The whole region was, eenturies ago. vonverted into an unprofit able marsh by repeated incursions of the sea, coupled with ohstruetions to the outward flow of the rivers Nene, Cam, Ouse. Welland. etc. Vast operations have been carried on ever since the time of Charles I.. by digging new channels and outfalls, and employing windmills and steam-engines to pump the water from the marshes and ponds into these artificial channels. The region is divided into the Yorth, the 1l iddle, the .'cola managed by commission ers, whose powers are derived from special nets of Parliament. The improved value of the land is the fund out of which the expense of the engi neering works i- defrayed. It was in one of
these di-triets (the :\liddle Level. between the Nene and the Old Bedford river•) that an irrup tion took place in 1;"02, which strikingly illus trate- the dependence of the safety of the whole region on well formed and %%ell-maintained embankment:.
There was a sluice, called Saint Germain's sluice, situated at. the confluence of the .11id dle Level main outfall drain with the River Ouse, near the upper end of another arti ficial channel, known as the Eau Brink cut. On ..)lay 4, 1Sfi2, this sluice gave way without the slightest warning; the tidal waters under mined the brickwork, and formed a hole in the bed of the river, into which the Nvork, of the sluice sank. The tidal waters rushed up the ((poling, and ebled and flowed a dis tance of 20 miles. ..11I attempt was made to throw an earth and cradle dam acro•. the drain, at about 300 yards from the fallen sluice; but this was relinquished in favor of a permanent coffer-dam of pile-work, at a distance of half a mile from the sluice; and after incessant exer tions from Alay 16 to dune I!), the tidal waters were at length effectually shut out by a strong dam. The failure of the Saint Germain's sluice was not the only irruption that had to be battled with; eight days after that failure, under the pressure of a high spring-title. the west bank of the drain gave way, on \lay 12, at a point about four tulles from the sluice; the bank had been built only to resist upland waters and not a rush and a pressure of the sea. The rupture carried away 70 yards of the bank, scouring out a hole )0 feet deep at the spot, and admitting a rush of water which covered 6000 acres of fertile land to a depth of two or three feet, increased at successive high tides to 10,000 acres.
In completing the repairs. it was decided to substitute syphons for sluices to carry off the water, but these, after being operated a number of have been abandoned in favor of a new sluiceway. The attempt to carry off the water from the fen-lands by gravity has in no instance proved completely successful. Pumping plants have therefore been installed here and flier', to carry off the water, either constantly, or 1100d n the valley of the Po, fi00.000 acres of marsh land have been drained and transformed into rich farm-land, the water being lifted off by pinups. The same kind of work has been done in the south of France.
In America. a large amount of land-rot-lama lion work, by gra vity-eanal systems. has been aceomplished in Florida. Illinois. Indiana, and linnesota. Two drainage canals have been con structed in the Red Hirer Valley of Nlinnesota, which have reclaimed 250,00u acres of land. one of these, which is 7 miles long, 20 feet wide at the bottom, and which varie. at depth from 3 to 10 feet, was •onstrueted at a eost of about II cents a (-tilde yard of excavation.
In Florida, the work of draining marshlands has been intrusted to various private emu pain,. under land grants or purchases. Some of the rompanies havt. construeted .oily the main drainage canal-, leaving the subsidiary canals and ditches to be dug by purchasers. Other