Hunt. — Notes on bloiriii// up Snags in the Waikato River ivith Dynamite. 161 



Aet. XII. — Notes on blowing up Snags in the Waikato River ivith Dynamite. 



By E. E. Hunt. 

 Plate III. 

 [Read before the Auckland Institute, 22nd October, 1877.] 

 The channels through the pumice sand in the "sunken forest" near 

 Eangiiiri, Waikato river, are constantly shifting and thus often expose new 

 "snags " or the remains of trees, which are very dangerous to steamers and 

 barges plying on the river ; as a proof of which may be mentioned the fact, 

 that three steamers and many barges of the Waikato Steam Navigation 

 Company have been snagged and sunk by them ; this company (of which 

 the writer is manager) whenever dangerous snags appear, blows them out 

 with dynamite, and a few remarks on their experience may not prove 

 uninteresting. 



Fu'st selecting a snag to be removed, a boat is moored above stream of 

 it and athwart the current, by anchors, bow and stern ; these steady her 

 in a breeze, and by their help the boat can be iDuUed up stream when the 

 fuse is fired, and after the explosion she can by them be dropped back into 

 exactly the same position as she had previously occupied ; this being 

 important as it sometimes happens that a second shot is required, and no 

 one who has not tried can imagine how difficult it is to find the same snag 

 or spot in running water after you have left it unmarked. 



Now, supposing the boat to be in position, the next thing to be done is 

 to carefully view the snag with a sub-aqueous telescope (if it may be so 

 named) made as per sketch (Plate III.). 



A hole is then bored down the stump with an inch-and-a-half auger to 

 three feet six inches below low summer level, that depth permitting the 

 steamers to pass over safely. 



Some dynamite and a cartridge previously prepared are then placed in 

 the hole, the fuse fired, and the boat hauled away about fifty feet, a perfectly 

 safe distance ; soon the explosion is heard, and then, usually, the snag is a 

 thing of the past. All this seems simple, but it is easier talked of than 

 done. 



The cartridge is made up watertight simply to prevent the cap getting 

 wet, water does not injure dynamite in the least. The sketch wiU show the 

 fuse (that coated with rubber is the best) inserted in the cap, which is about 

 an inch long, the cap is buried in the ignition charge, this being a particular 

 kind of dynamite, the charge is connected with one of the ordinary S^oz. 

 packets of dynamite, these are then wrapped in common calico, tied tightly 

 with string, and dipped into melted tallow or pitch to render the whole water- 

 proof ; attach this cartridge to a slight stick, long enough to reach from the 



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