440 BOARD OF AGRICULTURE. [Pub. Doc. 



larger tract of territory than could be reached from one 

 pump by the cyclone burner. For this purpose a large 

 spraying tank, holding one hundred gallons of oil and sup- 

 plied with a powerful pump, was used as a receptacle. This 

 was attached to a long line of iron piping for a conductor of 

 oil ; to this piping lines of hose were coupled, at intervals. 

 To each line of hose was attached an iron pole or nozzle, 

 similar to that used on the cyclone burner. By this device 

 one man could pump oil in sufficient quantity to supply six 

 burners, which would cover all the territory for several rods 

 from the tank. By means of the flexible hose a large strip 

 of ground could be burned over, when the tank and piping 

 could be moved forward and the operation repeated. 

 Where the ground was not too rough, burning over large 

 tracts of land was greatly facilitated by this improvement. 

 This manner of burning is illustrated by Plate II., opposite 

 page 434. 



Spraying Stone Walls and Stone Heaps. 

 It has been noticed, especially in the woods, that stone 

 walls, ledges and stone heaps form the centres upon which 

 the gypsy moth swarms and from which it spreads to the sur- 

 rounding country. There are several reasons for this : (1) 

 Stone walls are often flanked or overgrown with infested 

 shrubbery, and the caterpillars, finding no adequate hiding- 

 place within this growth, retire to the walls for refuge in 

 the daytime. There they are protected in a measure from 

 some of their natural enemies, and there later the moths 

 lay their eggs, which are also more protected than in some 

 other situations. (2) Where trees grow beside stone walls, 

 as happens in woodlands, the larvae, finding better protec- 

 tion in the wall than on the trees, retire to it, as in the 

 preceding case. (3) In heavily infested woodlands the 

 moths at times lay their eggs on leaves attached to the trees, 

 oftener upon dead leaves on the ground. The autumn gales 

 drive these leaves along until they catch on ledges, stone 

 heaps or walls, where many of them remain until the eggs 

 hatch. If the moths are left to themselves, therefore, each 

 spring sees an increased brood issuing from these stony shel- 

 ters. The economical treatment of eggs in walls, ledges and 



