EXPERIMENT STATION REPORT. 267 



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into them. The size of the tiles in the' main drain is marked 

 iu red ink on the plan. 



The laterals, of two-inch round tiles, are laid through the 

 middle of each plat, and have their outlet in the wells twelve 

 inches above the jjrade of the main drain. 



From the great practical, as well as theoretical, importance 

 of the experiments with drainage waters, extraordinary care 

 has been taken in laying all of the tilea in the system of 

 drainage, the slope or fall being the same in all cases to 

 secure uniformity in their action, and to prevent the forma- 

 tion of pools of stagnant water within the range of the tiles 

 to modify the composition of the drainage waters when the 

 drains are runninsf. 



'»■ 



Culvert. 



To secure an outlet for the main drain it was necessary to 

 make a deep cut across the roadway on the south line of the 

 experimental field, and make a new culvert to provide for 

 the surface-drainage in the spring. This culvert is made of 

 six-inch sewer pipe, resting on a wall of stones laid in cement 

 to a depth of four feet below the line of pipes, to prevent the 

 displacement of the sewer pipe by frost. A similar culvert 

 was also made across the roadway on the north line of the 

 experimental field. 



In the construction of the main drains many large boulders 

 were encountered in the lower twelve inches of the trench, 

 which, together with the compactness of the clay and 

 imbedded gravel, materially increased the cost of the 

 work. 



The work of digging trenches for the tile drains was begun 

 April 16th, and the laterals on the east tier of plats were 

 completed May 10th. From a delay in obtaining sewer pipe, 

 the wells were not finished until some time afterwards. 



Corn Experiments. 



An account of the experimental crop of corn grown on the 

 east series of plats, together with observations made on the 

 drainage waters, will be found in the paper marked B, ac- 

 companying this report. 



