FIG. 1 18. PROPER WAY TO MAKE CONNECTIONS 



Connections are all made by twisting bare wire ends securely 

 together. All wire ends should be scraped with an old knife so that they 

 will be free from grease or corrosion when connections are made. 



All bare joints or other uncovered places in the wire must be kept 

 away from water or damp ground. This can be accomplished by putting 

 a stick, block of wood or stone under the wire on each side of the bare 

 place. 



The Du Pont Company manufactures an instrument for testing 

 blasting circuits, called the Du Pont Galvanometer. This is a very 

 ingenious and useful instrument where much blasting is done by elec- 

 tricity, and saves much time in locating breaks in electric circuits. For 

 instructions as to its use ask for Galvanometer Booklet. 



Instructions for Agricultural Blasting 



In the following pages it is our endeavor to give as nearly as pos- 

 sible definite instructions as to the various methods employed to do 

 different kinds of blasting about the farm. Due to the diversity of 

 local conditions, such as nature of soil, thickness and quality of the sub- 

 soil or hardpan, the root system of trees, position and grain of boulders, 

 etc., it can be readily understood that it is practically an impossibility 

 to be able to outline any precise method of procedure, that will fit every 

 case, and accordingly it may be found of advantage to vary from the 

 instructions relative to the charge of explosives to be used. Nevertheless 

 if they are fully followed in a general way, but little experience will 

 enable the operator to do the work even more quickly and economically 

 than when first he attempts it. 



FIG. ii8A. MAKING HOLES WITH PUNCH BAR 



126 



