114 



MOSQUITO ERADICATION 



ditches may be obtained by using two or more cartridges to a hole 

 or by planting a second row of cartridges parallel to the first. In 

 this case, one electric cap should be used in each row of holes 

 or else an extra charge or two should be put in between the rows 

 to insure simultaneous detonation of all the charges. 



After the test shots have been fired and the proper loading 

 and spacing for the material in question thus determined, the line 

 of the ditch should be laid out; if the area is forested, all trees of 





Loading ^ Mow out a stump 



-Fuse 



^- Edge, of Proposed Ditrfi 



■ /Paivi of dynamite 



-/PorVS of dynamite 



Edge of Proposed Difch 



Lay -our far b/a sting ditch, hofes 6emq 

 Spaced /S" to 24-" a oar-t each 

 yray. 



r Edqe of proposed ditrfi ^ 



\ __~~^ Dynamite 



Section of Plant 



Attac/ting cap to dynamite 

 Fig. 74. — Sketches showing details of blasting ditches by propagated method. 



any size along the proposed ditch should be cut down and 

 removed. Then one man should make the holes with a crowbar 

 or shovel handle and a second should insert the charges. An 

 extra charge or two should be planted about large stumps, logs, 

 etc. Ordinarily lengths of from 150 to 200 feet may be dis- 

 charged at a time. The hole midway along this distance should 

 be fitted with a cap and fuse. When this fuse is ignited, the 

 concussion resulting from the explosion of this charge explodes 

 the other charges. 



