94 VEGETABLE FORCING 
The pan is inverted and the sharp edges forced 2 to 4 
inches into the ground. The pans should be of the 
proper proportions to work conveniently between posts 
and walks. They are simply shifted along the beds as 
fast as the soil is sterilized. In large greenhouses it is 
important to have at least half a dozen pans, for two men 
can easily tend to this number. In small houses heated 
by hot water it is possible to connect a steam hose with 
a portable engine, as shown in Fig. 30. 
Fig. 36.—A portable steam engine may be used for sterilizing small houses. 
A prominent Ohio grower has devised an apparatus for 
lifting and shifting soil-sterilizing pans which has proven 
highly satisfactory. He has kindly furnished the follow- 
ing description : 
“Tt consists of a square wooden frame slightly larger than the 
pan and about 30 inches high, with a small car wheel at each corner. 
Across the top of the frame is fitted a 1%-inch pipe with a bearing 
at each end, and on one end a worm gear with crank. Near each 
end of this pipe a 34-inch hole was drilled, and a 34-inch wire tiller 
rope was passed and fastened. This cable must be of sufficient 
length to reach across the frame, over a pulley at each corner of 
the frame at that end, and down to a hook in the corner of the pan. 
Thus, when the cables are properly adjusted as to length, the turn- 
ing of the pipe by means of the worm gear will wind the cable and 
