BLTRNING THE EGGS. 121 



as the fierce heat of the flame would fuse it. The wooden 

 cylinder into which the pipe was thrust was one and one- 

 fourth inches in diameter. The wood, being a non-conductor 

 of heat, was of great convenience in handling the pole. The 

 end of the pipe was fitted with a cyclone nozzle. The aper- 

 ture of this nozzle is very small, hence the value of the 

 strainer before mentioned, which prevents the entrance of 

 foreign substances with the oil and a consequent clogging 

 of the nozzle. The two men handling this apparatus filled 

 the tank with oil and then carried it to the spot where the 

 burning was to be done. One man then operated the pump 

 while the other handled the pole and nozzle. As soon as the 

 pump was started a tine spray of oil was thrown into the air 

 and ignited by a match. By means of the pole the resulting 

 fierce flame was carried among the undergrowth and over 

 the ground, destroying every living thing in its path. When 

 this work was carefully done, no eggs escaped except such 

 as were hidden in ledges or holes in the ground. An at- 

 tempt was made also with this apparatus to destroy eggs 

 which had been deposited in stone walls. (See Plate 

 XVIII.) Though this was partially successful in so far as 

 the fire reached and destroyed most of the eggs, those which 

 were deposited under the lower stones of the wall were un- 

 harmed, even though in many cases the stones were cracked 

 and broken by the heat. As it sometimes became necessary 

 to use this apparatus in burning out walls near growing 

 crops, a sheet-iron screen was set up between the flame and 

 the growing vegetables to protect them from the heat, being 

 moved along the wall as the work progressed. Burning 

 was thus done without any resultant injury to the gardens. 

 This machine, which has been christened the " cyclone 

 burner," would be most useful in checking invasions of 

 crawling pests like the army worm. 



Fire was also used in hollow trees, the eggs hidden within 

 them being destroyed by burning out the decayed wood. If 

 this is judiciously done, there will he no injury to the tree. 

 Unless great care is used, however, to extinguish the flame in 

 time, there is much danger of destroying apple trees in this 

 way. Cherry, oak and willow trees have rarely been injured 

 by burning out cavities ; indeed, some old trees appear to 



