78 THE FERTILITY OF THE SOIL [CH. 



But it was nearly two hundred years before the 

 plan was adopted on any wide scale by farmers or 

 landowners. In 1823 James Smith, of Deanston, 

 Perthshire, drained a marshy piece of ground in this 

 manner and converted it into a garden. The interest 

 of farmers in the experiment was aroused and main- 

 tained: in 1831 he set out the results of this and 

 other trials in his Remarks on Thorough drainage 

 and Deep ploughing. He recommended stone drains 

 (like Blith's) 2 to 2 ft. deep to be made in the furrows, 

 or, on flat land, 10 to 15 ft. apart in heavy soils but at 

 wider intervals in lighter soils. Josiah Parkes, the 

 drainer of Chat Moss, took a different view which he 

 defended in his papers in the Journal of the Royal 

 Agricultural Society (1846, etc.) and in his book 

 Philosophy and Art of Land Drainage (1848). He 

 maintains that drains should be deep not less than 

 4 to 6 feet but they could be placed at wider intervals. 

 The stones were soon displaced by John Reade's pipes 

 of 1843, which in 1845 were turned out by the 

 thousand in Thomas Scragg's machine. Throughout 

 the 'forties and succeeding years drainage became a 

 very popular improvement ; public loans were raised, 

 companies were started, and individuals expended 

 their resources in developing great schemes. But 

 the question of the depth of the drains was not 

 settled; considerable controversy went on between 

 the advocates of Smith's and of Parke's methods; 



