tlr}^ like a brick. A wet soil can never be tilled so as to present 

 the greatest amount of surface for film moisture and give it a 

 mellow texture to receive a gentle saturation of air ; and stand- 

 ing water robs it of much heat required by the soil and plants. 



8. Drainage makes a soil resei'voir. — There is a place in every 

 soil at which the free water stands. This place is called the 

 water-table. It may be three inches down, or a hundred feet. 

 It is the bottom of the soil reservoir, the bottom of our dish-pan. 

 This dish-pan, or the upper and tillable soil, is the reservoir. It is 

 the part in which the water is held as films on the soil particles. 

 These films travel from particle to particle, the general tendenc}' 

 being upward because the moisture is passing off near the top of 

 the soil by means of evaporation and appropriation by plants. 

 Moisture is constantly supplied from the water-table below. We 

 speak of this movement as capillary attraction. 



Under drainage lowers the water-table. It lowers the bottom 

 of the dish-pan ; and thereby there is a deeper reservoir above it 

 for the holding of film moisture and the distribution of roots. 



But, the reader says, if the water-table supplies moisture to 

 the upper soil, then it must be useful and necessary. Certainly j 

 but it must not be too high, for roots of farm plants do not thrive 

 in standing water. If the upper soil is well tilled, capillary 

 attraction will bring the moisture up. 



9. Do not let the moisture get away. — We. want this film mois- 

 ture in the upper soil in order that roots may use it. The plants 

 do not use it, to any extent, after it has passed off into the 

 atmosphere. Therefore, stop this water before it reaches the 

 atmosphere. 



How? Put a layer of loose dr}' earth between the moist soil 

 and the atmosphere. This laj^er will stop the upward capillary 

 flow (see Caption 3). This layer is the earth-mulch. It con- 

 serves, or saves, moisture. 



10. Dry and hard soils may be benefited by under-drainage. — 

 The water-table is lowered. Air is admitted. The soil does not 

 puddle. It becomes fine. Under-drainage makes wet soils dry 

 b}^ removing the free water ; it tends to make dry soils moist b}^ 

 deepening the reservoir and fining the particles of soil. 



11. What tillage tools are for. — Some tools, as plows, are to 



