96 VEGETABLE FORCING 



inch header with six l*4-inch outlets or laterals, placed 17 

 inches apart, the laterals being 45 feet in length and per- 

 forated with ^/6-inch holes 10 inches apart. The header 

 is placed crosswise of the bed to be sterilized, with the lat- 

 erals running lengthwise. The pipes are buried to a depth 

 of about 6 inches and the whole bed is then covered with 

 a heavy canvas. The header is connected with the heat- 

 ing system at the center, giving three lines on each side. 

 The Irondequoit grower referred to has also found 

 ordinary 2-inch corrugated galvanized conductor pipe 

 highly satisfactory. The pipes are light, easily forced 

 together and they cool very quickly so that shifts may be 

 made without discomfort. The perforations may be made 

 with a ten-penny nail. It is desirable to turn the pipes 

 with the perforations down, or to cover them with 

 burlap to keep dirt out of the holes. The perforated pipes 

 are simply buried in the ground beds under 6 or 7 inches 

 of soil, and the bed is covered with heavy canvas to retain 

 the heat. In a very large range at Ashtabula, Ohio, eight 

 gangs of pipe are used to keep quite a large force of men 

 busy shoveling soil and shifting the pipes. A 300 horse- 

 power engine is used in this establishment. 



Perforated pegs (Figs. 31 and 32) are used successfully 

 in some sections. This is sometimes called the "steam 

 rake" or the "steam harrow" method. These devices 

 may be made of any convenient size and dimensions. 

 The feed lines and arms are composed of a series of re- 

 ducing nipples with T's located so that the pegs will be 

 about 8 inches apart, giving the appearance of a harrow. 

 The arms of the feed lines may start with 24-inch pipe, 

 the second joint ^/2-inch and the third %-inch. The 

 ^4-inch pegs are flattened at one end into the form of a 

 wedge with a 3-16-inch perforation at the lower end for 

 the escape of steam. A heavy 1-inch hose connects with 

 the steam pipe that leads to the boiler. The sterilizer is 

 forced into the ground and covered with canvas which 



