The charge consists of several 1 } 4 x 8-inch cartridges of Red Cross 

 Kxtra Dynamite 40%, tied securely together with string, one of the 

 cartridges having been primed with a Victor Waterproof Electric Fuze. 

 When the charges for all of the holes are prepared they are connected 

 together and to the leading wires. Each charge is then lowered by the 

 electric fuze wires into the water and pushed under the down-stream ice 

 with the tamping stick. If the current is strong enough to carry the 

 charge down stream the electric fuze wires should be long enough to let 

 it float six or eight feet below the holes. In a slow current a block of 

 liglit wood may be fastened to each bundle of cartridges to make it float 

 against under side of ice. The explosion of all of these charges simul- 

 taneously by the operation of the blasting machine will break up the first 

 fifty or sixty feet of the channel and the broken ice will immediately 

 float away unless the current of the stream is very sluggish. In that case 

 the broken ice should be pushed out with poles into open water, before it 

 has time to freeze in place again. This same operation is repeated cutting 

 out fifty or sixty feet or more of the channel with each blast until the 

 gorge has been cut through. If the ice is from two to four feet thick the 

 charge in each hole should be from two to five 1*4 x 8-inch cartridges 

 of Red Cross Extra Dynamite 40%. In ice six to eight feet thick, each 

 charge must be increased to ten or twelve cartridges. When the ice is 

 thick, and large charges are necessary, the holes have to be from six to 

 twelve inches in diameter in order to get the bundle of cartridges through 

 them. These large holes can be cut through the ice more easily by 

 exploding half cartridges of the dynamite in small holes made with bars. 



In this work particular attention should be given to having the 

 dynamite in a well-thawed and soft condition when it is used, and to 

 guard against breaking insulation of fuze wires or withdrawal of fuzes 

 by the pull of the current. 



Ice is blasted from watering places for stock either by exploding the 

 dynamite on the ice or in the water under the ice. See pages 119 to 126 

 for proper methods of priming, charging, tamping and firing. 



Starting Log Jams 



To start log jams with dynamite the charge of several cartridges or 

 in some instances of many pounds of dynamite is exploded on or under 

 the logs forming the key of the jam. When small charges are enough, 

 the cartridges are tied in a bundle as when blasting ice. If charges of 

 fifty pounds or more are necessary the dynamite may be put in a bag or 

 left in the original wooden cases. The charge is primed with a Victor 

 Waterproof Electric Fuze and after being firmly secured in the proper 

 position is exploded from the shore with a blasting machine. 



Blocks in log rollways caused by rain and snow freezing and binding 

 the logs together are broken up by exploding charges of dynamite in 

 different places under the logs until they are loosened and can be rolled 

 apart. 



Red Cross Extra Dynamite 40% is recommended for starting log 

 jams and for opening the rollways. See pages 119 to 126 for proper 

 methods of priming, charging, tamping and firing. 



159 



