120 ANNUAL OF SCIENTIFIC DISCOVERT. 



of half the labor and time, and cost of material ; for, although 

 the cost of the material is 4 times that of blasting powder, its 

 effect is eightfold ; it is entirely free from danger, and does no 

 injury by the products of its decomposition. Into the wet drills 

 the material is introduced in sized paper-cartridges ; in some 

 cases, as in coal-mines, it is employed loose. The first is provided 

 at the point with a peculiar percussion-cap, and inserted in the 

 cartridge, reaching about an inch deep into the powder ; the whole 

 is covered with loose sand. 



As precautions against accidents, it must be avoided to raise 

 any dust with the dynamite, on account of its poisonous nature, 

 and the cartridges should be filled out of spoons, and both for the 

 sake of economy and safety, to reduce the calibre of the boring. 



The price of this substance, as sold by Nobel, is 42 cents per. 

 pound (gold), in 50-pound kegs, and 35 cents for 100 percussion- 

 caps. 



Should the statements of Mr. Nobel be confirmed in practice, 

 there is no doubt that this new agent will take rank as the only 

 and best blasting agent in existence ; for, if it be true, that the 

 substance is not injured by moisture, the possibility of poisoning 

 may be avoided by moistening the powder sufficiently to prevent 

 dusting. — Polytechnisclies Centralblatt. 



Late California papers contain accounts of the prodigious power 

 of this powder, as shown in some experiments tried in that State. 

 They recommend it highly, as being vastly more explosive, and 

 requiring much less drilling or preparation of the rock, than gun- 

 powder. 



EXPLOSIVES, ETC. 



Anthracite Gunpowder. — According to Mr. Ehrhardt, the inventor, 

 " The powder is composed of nitrate of potasli and chlorate of pot- 

 ash mixed in proper proportions with mineral carbon. Powder 

 thus compounded is less liable to accidental explosion, inasmuch 

 as it does not explode when ignited in the open air, but burns slowly, 

 something like common gunpowder when wet. But when con- 

 fined, as in a gun, or in a blasting hole in a rock, it explodes with 

 even greater force than ordinary' gunpowder. It is not much 

 affected by dampness, and generates but little smoke in burning. 



"To make this powder, the several ingredients must be finely 

 pulverized and then intimately mixed together. The more finely 

 they are pulverized the better. They require no other prejDara- 

 fcion. When the ingredients are well mixed the powder is ready 

 for use. The proportions of the ingredients ma}" be varied for 

 different kinds of work. For use in coal mines, I prefer to take 

 1 part by bulk of chlorate of potash, 4 parts of nitrate of potash, 

 and 5 parts of mineral coal. For blasting granite or othei* hard 

 rocks, I prefer to take 1 part of chlorate of potash, 2 parts of ni- 

 trate of potash, and 3 parts of mineral carbon. 



*' The mineral carbon may be either bituminous coal or anthra- 

 cite, but I prefer to use the anthracite known as * red ash.' 



