DRAINING OF THE LAKE OF HAARLEM. 419 
portionally and driven southwards, while winds from the south 
tended to create a flow in the opposite direction. The shores 
of the lake were everywhere low, and though between the years 
1767 and 1848 more than $1,700,000 had been expended in 
checking its encroachments, it often burst its barriers, and 
produced destructive inundations. In November, 1836, a south 
wind brought its waters to the very gates of Amsterdam, and 
in December of the same year, in a north-west gale, they over- 
flowed twenty thousand acres of land at the southern extremity 
of the lake, and flooded a part of the city of Leyden. The 
depth of water in the lake did not, in general, exceed fourteen 
feet, but the bottom was a semi-fluid ooze or slime, which par- 
took of the agitation of the waves, and added considerably to 
their mechanical force. Serious fears were entertained that 
the lake would form a junction with the inland waters of the 
Legmeer and Mijdrecht, swallow up a vast extent of valuable 
soil, and finally endanger the security of a large proportion of 
the land which the industry of Holland had gained in the 
course of centuries from the ocean. 
For this reason, and for the sake of the large addition the 
bottom of the lake would make to the cultivable soil of the 
state, it was resolved to drain it, and the preliminary steps for 
that purpose were commenced in the year 1840. The first 
operation was to surround the entire lake with a ring-canal 
and dike, in order to cut off the communication with the [j, and 
to exclude the water of the streams and morasses which dis- 
charged themselves into it from the land side. The dike was 
composed of different materials, according to the means of 
supply at different points, such as sand from the coast-dunes, 
earth and turf excavated from the line of the ring-canal, and 
floating turf,* fascines being everywhere used to bind and com- 
* In England and New England, where the marshes have been already 
drained or are of comparatively small extent, the existence of large floating 
islands seems incredible, and has sometimes been treated as a fable, but no 
geographical fact is better established. Kohl (Jnseln und Marschen Schleswig- 
Holsteins, iii., p. 809) reminds us that Pliny mentions among the wonders 
