WATER STORAGE AND CANALIZATION. 319 
_ The kingdom of the Netherlands for its size contains a 
_ greater number of navigable canals than any. They were 
commenced partly for drainage, partly for navigation, as early 
as the 12th Century, and proved of ial ady to 
Flan which, by their means became the entrepdt of 
the commerce between North and-South Europe. At present 
they permeate the country in every direction, and have led to an 
enormous trade between Holland and every part of France and 
Germany. The yearly profits of the canals is estimated at £625 
nearly level. Their banks are very thick, as they are the 
great drainage arteries of the country, and any breach might lead 
"spectively, and its average depth is 203 feet. It has only two 
ry locks, one at each extremity, and was constructed for 
eh of 6 miles of river navigation ; 95 feet wide at water- 
Vessels of 1 
a 
; of country produce are 1from St. Petersburg to the Caspian 
Sea, 1,434 miles, by water passage, whilst the iron and furs of 
aes and the teas of China are even now to a certain extent 
_ veyed to St. Petersburg through a similar channel. : 
England has no less than 2,300 miles of canal and 1,800 miles 
