TILE DRAINAGE 105 



from the cuplike depression during heavy showers or siiow- 

 IhaAvs. Then in the depression he laid a system of laterals, 

 pretty close together, and joined each to the main, to take 

 the surface-water down and into the main rapidly. He re- 

 ports that it works perfectly, as do other smaller systems of 

 drains without outlets, on his farm and others. But for this 

 you must have a gravelly, sandy, or other quite porous sub- 

 soil. 



SILT OR SAND WORKING IN AT THE JOINTS. 



On this subject, as well as the foregoing, I have had no 

 experience, as all my drainage has been where the subsoil is 

 clayey. Hut I have received so valuable a letter from Mr. 

 W. Trowbridge, of Painesville, O., that I here give the main 

 part of it. 



This and most of the other queries and suggestions that 

 follow came to me because of my articles in The Ohio Farmer, 

 and most of them have been answered in that paper in sub- 

 stance as here. Mr. Trowbridge says : 



I do not now remember of your saying any thing about 

 covering the joints of the tile with any other material than 

 earth. Now, will you please allow me to make a suggestion 

 or two? 



1. As to covering the joints, perhaps in a tenacious clay no 

 other covering than the material taken from the ditch is 

 needed. But soils reqummj draining are not all days. Where 

 I have (lone the most of my work, the soil is sandy and a 

 black friable loam, underlaid at a depth of from two to five 

 feet with clay. The question was, how to keep the fine sand 

 from entering and filling the tile. I think I have solved the 

 problem in a very satisfactory way, at least to myself. I am 

 using common building-paper, cut into pieces to suit the size 

 of the tile (for 2-Hnch tile, 2x8i inches is about right). One 

 of these pieces, laid over each joint, effectually pi events the 

 silt from entering the tile, at least as far as the paper ex- 

 tends. In laying the tile I always carry a mason's trowel in 

 my hand, and, after placing the two ends of the tile as close- 

 ly together as possible, place a trowelful of earth directly on 

 each paper as laid. 



I have uncovered tile after it has been in the ground three 

 years, and always found the^paper^intact^and excluding the 



