i6i 



The explosives which I have used are rackarock and rendrock. 

 I consider the latter the better for earth holes, as it seems to take 

 more roots with the stump ; but I can recommend both. I have used a 

 little gelignite, and it seems very good ; I intend to give it further 

 trials. Other explosives are worthy of trials, but I should not advise 

 farmers to use dynamite, as it is more subject to chemical changes, 

 particularly in hot climates. 



If rackarock is used, insert the detonator in half a plug of 

 gelignite for earth holes. Much better combustion will result if this 

 is done. 



Bursting the Timber. 



When it is desired to burn trees or stumps level with the ground, 

 or to burn 'sound logs, bore holes I to 2 feet deep into the soundest 

 part of the timber, with I inch to I ^ inch auger, and charge same 

 with Yi lb. to I lb. of explosive. A number of shots fired simul- 

 taneously with the battery will do very much better work than 

 when they are fired singly with fuse. This method is suitable for 

 Yankee grubbing, as it uses less explosive ; but is not as good as 

 the next method for getting rid of trees and stumps. 



Clearing for the Plough. 



To remove trees and stumps for the plough, put holes under 

 the heaviest and soundest parts of same, 12 inches or more in 

 depth, with a 3-inch earth auger or small bar and scraper. When 

 placing the charges, take into consideration the lay of the main 

 spur roots. Best results are obtained by using three charges or more 

 according to the size of the tree. Place each ciiarge up against a big 

 strong root, or better still in the fork of two roots. If it is not easy 

 to get the charge against a root, ram small stones into the bottom of 

 the hole, so as to make a sound bottom for the charge, as the more 

 resistance obtained the better the results of the explosion. Do this 

 before any explosive is put in the hole, or there would be great 

 danger. 



In some cases it is better to use both earth and wood holes, 

 placing the latter in big spur roots ; but I rarely do so, as it snaps the 

 roots and leaves portion in the ground. 



The charges should be carefully tamped with damp clay or earth 

 observing the proper rules, as there is considerable danger if they are 

 neglected. Water tamping is not at all effective in wood, though it 

 is in rock. 



In earth holes I find I lb. of explosive about the minimum effec- 

 tive charge for large trees and stumps; but I have blown out small 

 stumps with as little as 34 lb. With well-placed charges stumps 

 frequently come out, shattered into many pieces, leaving few if any 

 rojts. When any remain they are so shattered that they burn easily 



