LECTURES AND ESSAYS READ AT INSTITUTES. 299 



fertile a condition as we received it. To obviate these diflScultics, a thorough 

 under-drainage is indispensable. Its effect is to remove surplus water, dis- 

 tribute a more even temperature of heat and moisture, to largely prevent 

 washing, and to lengthen the season for labor and for the growing crops. 



To make under drainiug a complete success, a systematic plan must be 

 adopted to suit the conditions of soil, lay of land, and surrounding circum- 

 stances. And as the soil and lay of land vary widely, no definite plan can 

 be laid down in detail to fit every farm alike; therefore, to remedy this diffi- 

 culty, general principles must be applied, leaving the details to be carried out 

 according to circumstances. After having decided upon apian for a thorough 

 system of under-drainage, it will be seen that the work can be divided, and a 

 portion of the work done at such time as will best suit the farmer's con- 

 venience. 



GEKEBAL PLAN. 



The main channels of the drains should be laid and extended through the 

 lower portions of the farm, running as direct to the outlet as practicable. By 

 taking the shorter cuts with the main drains it will be seen that a greater 

 quantity of water can be discharged in a given time, and the cost of laying 

 the drain is less, as less large and expensive tiles are required. The lateral 

 drains should be laid in sufficient number to make the work thorough, 

 although it is not necessary to complete the whole job at one time. The 

 main drains should be laid first, and the laterals may be laid or postponed, as 

 will best suit the farmer's convenience. 



The depth to lay tiles should be governed by circumstances. On ordinary 

 clay soils from three to four feet deep is considered to be about right. The 

 main drains should be on a lower line than the laterals, and the mouth of the 

 laterals at their junction with the main drain, should be slightly turned down 

 stream, to prevent their obstruction with floating silt in the main drain, and 

 by laying the top of the cavity of the laterals on line with the top of cavity of 

 the main drain would give sufficient fall to force back into the main drain any 

 substance that may have been forced into the laterals during a high pressure 

 of water in the main drain. 



MANNER OF DETERMINING SLOPE. 



On ordinary rolling land where there is one or more inches fall to the rod, 

 the slope in the bottom of the ditch may be made by means of a curved blade 

 spade, in the hands of a good workman, and an even grade determined by the 

 trickling stream of water that is usually found in clay soils when tliey are wet 

 enough to make ditch cutting profitable. But in the absence of water in the 

 ditch, or on very level lands, a survey will be found to be necessary to insure 

 accuracy. 



MANNER OF LAYING TILES. 



After the bottom of the ditch has been graded with as true a slope as the 

 surface of the land will well allow, and leaving no sags for the water to stand 

 in, the tiles may be placed on the side of the ditch in reach of the workman, 

 who stands in the ditch and begins to lay the tiles at the upper end of the 

 ditch, carefully plugging up the upper end of the first tile with a stone, or 

 some hard substance that may not rot, or be displaced, to allow water and 

 mud to pour in at the end of the drain. The workman should be provided 

 with an implement in the form of a trowel or spade, with a concave blade, to 



