62 



enough to indicate that the plant should have as much 

 water supplied to it as can be taken up by the roots. I 

 believe no argument is needed to convince my hearers 

 that for greenhouse crops sub-watering is immensely 

 superior to any system of surface watering. Since the 

 presentation of my paper before this Society a year ago, 

 many articles have been published commendatory of the 

 method, and a number of practical and theoretical points 

 elucidated that were not touched upon in my necessarily 

 brief paper. 



From what has been published, and from my rather ex- 

 tended correspondence, I am more fully than ever convinced 

 that the use of tile for supplying water, and make-shifts 

 in place of a thoroughly watertight bench bottom, which 

 are generally selected on account of cheapness, are likely 

 to bring disappointment. The most satisfactory lining, 

 probably in the order named, is zinc, galvanized iron, or 

 cement, which should extend three or four inches up the 

 sides of the bench, or to the top, if the expense does not 

 seem too great. The bottom is then covered with four 

 inches of porous bricks, set so close together that soil will 

 not drop between them ; and ample space is provided for 

 water and air to circulate freely by removing about a half 

 inch of the lower edges of the bricks before setting. The 

 bed is then filled with soil in the usual manner. 



Water is run into the bottom of the bench through an 

 inch tube set at intervals of five to ten feet along the 

 front edge, or an even better way probably is the plan I 

 recently saw in use in Mr. Fred. Dorner's houses, of using 

 a flue about two by six inches instead of the tube. 

 Mr. Dorner's plan permits water to run in a little easier 

 from the hose, and does away with any necessity for 



