98 SCIENCE WITH PEACTICE, 1812 TO 1845 



land is also robbed of its own natural fertility as well as of 

 artificial means for its enrichment. If the soil rids itself 

 of the surface water by evaporation, its temperature is 

 chilled. A wet cloth wrapped round a bottle in hot 

 weather acts as a refrigerator ; the same effect is produced 

 upon the soil by evaporation. But Smith's system made rain 

 a friend and not an enemy. In winter undrained land is 

 saturated with water ; in summer, baked so as to exclude 

 all air ; in frost, bound in a coat of iron. The object of 

 Smith was to change the texture of the soil, to draw off 

 the water and admit the air, and thus to communicate that 

 divisibility and mellowness which farmers call friability. 

 Drainage gave the farmer twice as many days on which he 

 could work his land ; it increased the efficacy of his farming 

 operations and of his manures ; it secured an earlier seed- 

 time and an earlier harvest, raised the average produce, 

 and lessened the expenses of working. On pasture land 

 its benefits are not less obvious. Drainage destroys coarse 

 aquatic plants, increases the sweetness and nourishment of 

 the herbage, and affords a full bite to cattle weeks before 

 undrained land. 



Much remained to be effected in the details of drainage 

 after Smith had demonstrated its principles. But within 

 the next ten years Josiah Parkes (1843) had brought his 

 practical and scientific knowledge to bear upon the subject, 

 the necessary appliances had been simultaneously provided 

 by Reed's cylindrical pipes (1843) and Scragg's machine 

 (1845) for their manufacture, and the necessary capital 

 was offered to landlords upon easy terms by loans provided 

 Tinder the Act of Parliament of 1846. 



Drainage chiefly helped one class of farmers, new 

 manures assisted all. In the infancy of agriculture little 

 or no attention was paid to the use of manure. Fitzherbert 



