AGRICULTURAL EXPERIMENT STATION. 141 



as follows : A cylinder of galvanized iron ten inches in diameter 

 and twenty inches high with a row of perforations about an eighth 

 of an inch from the bottom is soldered into the center of a pan 

 fourteen inches in diameter and three inches high. At the top of 

 the pan a collar is soldered to the cylinder and to the pan, 

 which has a perforation for the introduction of water into the pan. 

 Through the bottom of the pan outside of the cylinder pass two 

 tubes, one being flush with the bottom of the pan on the inside 

 and the other extending up into the pan just two inches. Both 

 extend about two inches below the bottom of the pan. 



The first tube is for washing out the pots and is corked when 

 the pots are in use. The second is the overflow tube which 

 regulates the height of the water in the reservoir. A little below 

 the top of the cylinder handles are soldered to opposite sides 

 for convenience in handling the pots. The inside of the pots were 

 painted with asphaltum paint to prevent rusting, and the outside 

 with white lead to prevent undue absorption of heat. 



Pots of the above description were filled to the depth of one 

 inch with coarse gravel and then to the top with crushed quartz 

 sand. It required for this purpose 65 pounds of sand for each 

 pot, with the last 35 pounds of which was mixed the fertilizers 

 used in the experiment. 



These pots were set in double rows on a bench running nearly 

 North and South. Water was then introduced into the reservoirs 

 until it rose to the top of the overflow tube under which there had 

 previously been placed glass jars. The water passing through 

 the perforations in the cylinders rose to the height of two inches 

 on the inside, so that it stood in all of the pots eighteen inches 

 from the top. Rain water from a slate roof was supplied to the 

 pots daily to make good the loss by evaporation, except that after 

 rains when the water falling on the pots caused an overflow of the 

 reservoir into the glass jars below, the overflow water was used 

 for watering the pots. 



In each of these pots were planted twenty oats of the same 

 variety. After they had grown to the height of about three inches 

 the plants were thinned out to eighteen to the pot on account of 

 one or two plants having died in some of the pots. The oats 

 rusted badly which doubtless depressed the yield in all of the pots, 

 and to this may in part be attributed the variation in yield of pots 

 receiving like treatment as to fertilizers. 



