100 



Nitro- Glycerine. 



plosive, and with properties, besides, of which we had little 

 or no knowledge. Obviously we must proceed with extra- 

 ordinary caution. By very gradually warming a mass of 

 sixty pounds, we found it was nitro-glycerine in combina- 

 tion with 20 per cent of water, and that this combined water 

 could be separated, and then it was at least merchantable. 

 But did it possess positively the blasting force of our usual 

 make ?. In the experiments we undertook to ascertain this 

 point, we discovered that it was readily and easily exploded, 

 and it became a question whether it would not be advisable 

 to destroy it all, rather than introduce it for use, or sell it 

 to our customers. We finally ascertained, that by mixing 

 it with three times its volume of our usual tri-nitro-glycerine, 

 this sensitiveness to a blow or shock, was removed. 



"We then set about gradually warming it, to separate 

 the water, in a room heated by steam. On Saturday eve- 

 ning of March 11th, 1871, the watchman who has charge 

 of the works and magazines at night (the works had been 

 suspended during the week, owing to my absence at Wash- 

 ington), thought he would make up the fire under the steam- 

 boiler some 300 feet distant from the magazine and go to 

 bed. He did so. It was warm, close weather, and on Sun- 

 day morning at 6 J o'clock, the neighborhood for two miles 

 around was startled by a terrible explosion. Eighteen 

 hundred pounds of this non-explosive (?) nitro-glycerine 

 had gone off, and twelve tins filled with congealed nitro- 

 glycerine, in an adjoining shed, amounting to 672 fbs., had 

 been blown, part of it to some distance, but most of it buried 

 in the mass of earth, splinters of joists, debris of stones, etc., 

 caused by the explosion. Although the containing tins, 

 as you will perceive by this photograph, are corrugated, 

 contorted, and perforated, not a particle of the tri-nitro- 

 glycerine had exploded, nor was any one injured. Thus 

 were we relieved of dangerous company and $3,000, a 

 moderate price for the benefit conferred. For, thereafter, 



