2 The Drainage of Fens and Low Lands. 



the particular work required, and to be able to draw up such 

 a specification that tenders for the work may be furnished 

 upon a similar basis. While a certain amount of freedom as 

 to details may be allowed to the makers tendering for the 

 machinery, the responsibility of the successful carrying out of 

 the work must rest with the engineer. 



The want of sufficient knowledge of this special subject, and 

 experience of what has been done, has led in several cases to 

 the erection of unsuitable machinery, waste of money, and 

 failure to effect the object required in the most effective and 

 economic manner. 



Very large tracts of rich land suitable for cultivation lie at 

 so slight an elevation above the sea, that this land can only 

 be rendered fit for cultivation by artificial means. The 

 Polders in Holland, the Fens and marsh land in England, the 

 sites of old lakes in Italy and other parts of Europe, and con- 

 siderable quantities of low land in the delta of the Mississippi 

 and in South America and the colonies, have been brought 

 into cultivation and made to yield large quantities of pro- 

 duce by a complete system of drainage. In India, Egypt, 

 and California, on the other hand, large areas of land are 

 rendered fertile, and made to grow abundant crops of fruit and 

 other produce, by means of irrigation; for this purpose, besides 

 channels carried from the rivers in the higher districts, mecha- 

 nical agency is largely resorted to for lifting the water into the 

 irrigating channels. The steam engine and centrifugal pump 

 are now rapidly replacing the more ancient and simple means 

 of lifting the water. 



In Holland the reclaimed land, consisting, for the most 

 part, of the beds of lakes, is at so low a level that pumping 

 has been almost universally resorted to. 



In the valley of the Po upwards of 600,000 acres of marshy 

 land have been drained and transformed into rich country by 

 means of pumps and lifting wheels, the drainage of which was 

 only practicable since the introduction of steam power, owing 



