3Q 



THE APPLE 



by dipping or pumping methods. However, the rotary pumps have 

 given general satisfaction when the lighter oils have been used. 



The cistern walls should be from 6 to 8 inches thick to 

 give the best results. The floor need not be so heavy, 

 probably 4 inches thick being sufficient. The mixture 

 used should be composed of about i part of cement to 

 2 or 3 parts of sand. If crushed rock can be used in mix- 

 ing the concrete, I part of cement, 2 to 3 parts of sand, 

 and 4 or 5 parts of crushed rock will give good results. 

 The walls should then be finished with cement plaster, 

 thus giving a smoother surface. The whole inside should 

 be painted with two or three coats of asphalt paint. 

 Paraffin has not given thorough satisfaction among some 

 of the Middle-West growers. The roof of the cistern 

 can be made of a reenforced cement slab. This slab 

 will vary in thickness according to the width of the 

 cistern, but if it is not over 8 feet wide, a well reenforced 

 slab 5 inches in thickness should be sufficient. 



A method of distribut- 

 ing the oil. In the dis- 

 tribution of the oil, wagons 

 holding 300 to 400 gal- 

 lons will be the best size. 

 These should be suffi- 

 ciently high so that good 

 pressure can be obtained 

 at the end of the hose 

 used for filling the pots. 

 A tank for this purpose 

 can be secured at from 

 $15.00 to $20.00. If 10 

 acres or more are to be 

 protected, it will be well 

 to provide two wagons ; 

 and as these can be used in transporting the oil from the tank 

 car, they will be found almost indispensable. It is very important 

 that these tanks be perfectly tight and that pipe connections 

 be tight, with good solid valves. Handling the oil is a dirty job 



Fig. 8. Torch and can used in orchard heating 

 (Iowa State College Experiment Station) 



