456 Mr. Downing on the Drainage of Haarlem Lake. 



It is true, the sea is raised at Katwyck sluices, but here the rise and fall 

 of the tide is so much greater than in the Zuyder Zee that, unless in great 

 storms, these always have some discharge at every low water. The action of 

 the tides is irregular, and almost disappears on the northern part when the winds 

 are high. If, then, Lake Haarlem be laid dry, it is evident this mode of lower- 

 ing the basin of the Eynland must cease, and that too, at a time when, from the 

 diminution of the area of the basin, which I have mentioned, the position of the 

 district had become more critical. We may now more readily understand how 

 it was that so many different projects were put forward, and such a length of 

 time elapsed, before this work, which seemed in different ways to compromise 

 the safety of the rest of the Eynland, was finally undertaken. It was under 

 consideration for 200 years ; fifteen different projects having been mooted in 

 that time. It was, however, in a manner forced upon the Government by the 

 dangers arising from so vast a body of internal water, surrounded by shores of 

 such yielding material as peat. 



The fresh-water lakes of Holland, although seemingly so sluggish and inert, 

 yet contain within themselves a principle of increase: most frequently formed 

 by the cutting away of turf for the purpose of fuel, and separated from each 

 other by narrow intervening banks ; a storm arising, drives the waters with 

 fury against the too yielding bank — this soon disappears, and the area of the 

 united waters falls with increased power upon the next opposing mass, which 

 in its turn gives way, and after some years a large and dangerous expanse of 

 waters is seen, which can only be restrained from further injury hy expensive 

 works. It was thus that Lake Haarlem, which in 1531 consisted of four small 

 contiguous lakes, was gradually formed ; the boundaries of these are given in the 

 map, Fig. 1, Plate X., with the several dates upon the lines showing the then 

 boimdaries of the waters. It was only by lofty and expensive dykes along 

 the eastern shore, and an expenditure of about £5000 a year in repairs, that 

 it was prevented joining the Lakes of Aalsmeer, and finally attacking Amster- 

 dam itself 



On the 9th of November, 1836, a violent storm from the south-west forced 

 the waters over the dykes, and flooded all the lands up to the gates of Amster- 

 dam, causing great destruction of property; and, on the following Christmas 

 Day, an equally violent gale from the opposite quarter drove the waters over 



