12 FARMERS' BULLETIN 996. 



method of determining the work done by a steaming outfit. Although 

 the temperatures reached directly under the pan are quite high, little 

 heating effect is to be noted away from the edges of the pan. 



Clay soils, because of their heavier texture, require longer periods 

 for ^teaming than sandy soils. Steam penetration and heat conduc- 

 tion are not as rapid as in the more open sandy loams, and it is espe- 

 cially important that these soils be as dry as possible at the time of 

 steaming. The moistening of the soil by rainfall or snow just before 

 steaming prevents the rapid heating of the soil and the full penetra- 

 tion of the steam, and the efficiency of the work is greatly reduced. 



COST OF STEAMING. 



Contractors who furnish the boiler and a fireman may charge ac- 

 cording to the area steamed at an average rate per 100 square feet, or 

 they may charge a flat daily rate. The charges for this work vary in 

 the several tobacco-growing sections, ranging from 50 cents to $1 per 

 100 square feet, or from $6 to $12 a day, and the contractor may or 

 may not furnish the pan and fuel. 



The fuel consumption is usually reckoned at one-half ton of soft 

 coal for every 1,000 square feet of seed bed. 



Where the grower owns the boiler, the costs of operation are some- 

 what lower. The average area covered in a 10-hour day is 1,000 square 

 feet and the cost is approximately $6. It is also better to use two 

 pans, so that there may be no delay in steaming due to the shifting 

 of the pan. One attendant is required constantly to fire the boiler ; 

 three others must be ready at intervals during the day to help him 

 move the pans. 



The labor cost can be reduced considerably by using a rack for lift- 

 ing the pan. For this rack two pairs of buggy or light wagon wheels 

 set on axles a little longer than the width of the pan are joined to- 

 gether by a light frame. This frame should be 4 feet shorter than 

 the pan. A long rod or lever is attached in the middle of each end 

 of the frame, to allow for the easy lifting of the pan. The lever is 

 provided with a hook at the end of its resistance or lifting arm. To 

 the ring bolts at each end, a substantial rope is fastened with suffi- 

 cient play for the hook of the lever to hold the rope conveniently, 

 By hooking the rope and using the frame of the carriage as a ful- 

 crum, the pan is lifted. The lever arms can be hooked in position by 

 a wire or clutch after the pan is lifted. The sides of the seed-bed 

 frame form a guide for the wheels, thereby making it a simple op- 

 eration for one man to handle and move a pan. 



On account of the possible occurrence of rains and snows during 

 the period for sterilizing, it is advantageous even on small farms to 

 operate 24 hours per day in favorable weather. Large growers do 

 this because of the convenience and economies in fuel and labor. 



