504 



On the Advantage of Deep Drainage, 



In this calculation the quantity of water which fell on the few 

 acres shaded with trees was thrown out of view. From these 

 results it would appear that rather more water had been dis- 

 charged by the 3^ drains than by the 3-feet drains, though the 

 latter were twice as numerous as the former. In those parts of 

 the field therefore drained by the 3-feet drains there was more 

 water left in the land, or went off by evaporation; and there was 

 also less depth of soil for the roots. This fact seemed to explain 

 the produce obtained. If the number of stooks afforded a correct 

 criterion of the quantity of straw, there was most straw on the 3- 

 feet drains, and most grain on the 3^-feet drains; from which he 

 would infer that a damp soil, though favourable to large produce 

 in straw, was unfavourable to large produce in corn. The o.V-feet 

 drains probably produced with greater dryness greater warmth, as 

 the larger quantity of rain which they carried off would impart to 

 the soil a. greater amount of heat. Why the 3iy drains, though 

 one-half as numerous as the 3-feet drains, should carry off as large 

 or a larger quantity of water, was a separate question. Of course 

 the deeper drains would draw from a greater extent of surface ; 

 but he had not anticipated that a 3^-feet drain would have drawn 

 off double, or rather more than double, the quantity of water that 

 a 3-feet drain draws. The water-meters, however, showed that 

 this had been the case, unless indeed there were springs in those 

 breaks where the deeper drains were. He was not aware that any 

 such springs existed. The subsoil was pretty uniformly retentive 

 throughout the field; and the upper soil was not perceptibly 

 more open in one part than in another. So far, therefore, as his 

 experiments had proceeded, they showed that if drains were 

 made 3J feet deep, only one-half the number will produce the 

 same or a little better effect than 3-feet drains. The expense per 

 acre of the former, in the field referred to, had been 41. 6s. 4d. ; 

 of the latter 8/. 12s. 4^d. Mr. Milne stated that he had heard 

 of a similar experiment having been tried in East Lothian by Mr. 

 Hope of Fenton, with an opposite result. He had seen no 

 account of Mr. Hope's experiment ; but if correctly reported to 

 him it would lessen his confidence in the results obtained by him- 

 self, and would be an additional inducement to persevere with his 

 observations, in order to obtain further data for coming to a right 

 conclusion. Probably, in another year, more correct data could 

 be obtained, as in a few months only after the drains were made 

 the soil could not have been opened very thoroughly. He had 

 last winter put the subsoil plough through the field, and he would 

 endeavour to ascertain what was the produce of this year's crop 

 on the several divisions, and report the result to the club. One 

 thing was quite evident, that with almost any system of drainage 

 the increased produce amply compensated the cost. From the 



