PROTECTING OKCHARDS AGAINST FROSTS. 269 



area under experiment was small, consisting of only an acre 

 or two. At other times movable fires were made by piling 

 eai-th in a wagon and building upon the mass a fire of smoul- 

 dering material. Uy moving from place to place the smoke 

 was distributed where it seemed to be most needed. 



By the most conscientious work it seemed impossible to 

 raise the temperature more than a degree or two, even under 

 the most favorable conditions. 



Three years ago a test was made of the value of refined oil 

 (kerosene) as a means of creating a smudge and for gener- 

 ating heat for warming the orchard. Porous bricks were 

 soaked in the oil, and when stood on end and lighted would 

 burn for almost an hour. Not enough smoke was formed to 

 be of any practical value as a smudge, and the flames pro- 

 duced by the burning bricks were too small to exert much in- 

 fluence upon the temperature. However, by using the burn- 

 ing bricks at the rate of about 100 per acre there was a raise 

 in the temperature of one or two degrees, but only for a short 

 time, as it was found impossible to keep a sufficient number 

 of bricks burning lively at the same time and continued long 

 enough. 



This experiment was tried in the apple orchard and our 

 best efforts could not prevent the formation of frost. 



On the next night when there was a still heavier frost an 

 attempt was made to protect a peach orchard. On this occa- 

 sion coal tar was used to supplement the kerosene. Various 

 devices were resorted to to generate heat and smoke from the 

 two combustibles mentioned. By pouring tar over excelsior 

 a dense smoke was created and considerable smoke was 

 formed. But perhaps the best success attended the use of tar 

 in tin cans which were set upon the kerosene-saturated bricks. 

 The latter upon being lighted furnished enough heat to boil 

 the tar, which soon ignited and burned fiercely. These fires 

 were kept up during the hours of early morning, and for the 

 most part where the fires were well distributed the fruit was 

 saved. At this time the peaches were half an inch long and 



