72 THE FERTILITY OF THE SOIL [CH. 



shall not reach the low-lying lands, (2) the water 

 inside the low-lying area is drained into ditches and 

 pumped into the river. To effect the first purpose a 

 catch- water drain is cut at a point just above flood 

 level and arranged to discharge by gravity into the 

 nearest river. The second purpose is achieved by 

 making open drains inside the catch- water and bring- 

 ing them to the most convenient point for discharge. 

 The water collected in these is below the level of the 

 river and will not naturally flow in, but has to be 

 lifted there. This is done by large scoop wheels, 

 which are simply under-shot water-wheels driven the 

 reverse way. In olden times power was furnished by 

 windmills, and now-a-days by the less picturesque 

 beam engine. Oil engines and centrifugal pumps are 

 often used in new work. 



The reclamation of Whittlesea Mere near Peter- 

 borough (Holme Station) affords an interesting in- 

 stance of this type of problem. The Mere itself 

 covered 1000 acres, and around it lay another 2000 

 acres of wet land or shoals. In 1844 an Act was 

 obtained to improve the drainage of the Middle 

 Level; a new cut 11 miles long was commenced to 

 discharge the waters some six miles further down the 

 Ouse than before, and so effect a lowering of the 

 water table by six feet Simultaneously connection 

 was made with the Mere. In the summer of 1851 

 the new cut was sufficiently advanced to carry off the 



