"How about thunder-storms?" I asked.
"There is always danger," said the expert, "and all hands hurry out of the works as soon as the lightning begins to play. If a bolt struck a lot of dynamite it would set it off."
Then he explained that the policy of dynamite manufacturers is to handle explosives in small quantities, say a ton at a time, each lot being finished and hauled away in wagons before another lot is started. This is possible because of the short time occupied in making dynamite. He assured me, for instance, that if there were only raw materials at the works on a certain morning when the seven-o'clock whistle blew, it would be perfectly possible to have a ton of dynamite-cartridges finished, packed in boxes, and loaded on freight-cars by nine o'clock.
After this some one told of a thrilling happening in the mixing-house, by the great vat, wherein nitroglycerin is mixed with porous earth, called dope, and becomes dynamite. Over this vat four men work continually, two with rakes, two with hoes, kneading half a ton or more of explosive dough to the proper consistency.
One day a powder-car loaded with heavy stone got loose on its track a quarter of a mile up the slope, and started down the steep grade. The tracks ran straight into the mixing-house. The switch was open, and the first thing these men knew, there was an angry clang at the switch, and then a swift, heavy car was plunging toward the open door, with every chance that it would set off twelve hundred pounds of dynamite there. Workmen outside shouted, and then stared in horror. Not a man in the mixing-house moved. All four kept their places around the vat, held tight to their rakes and hoes, while the car, just missing the dynamite, hurled its mass of two tons through the back wall of the building, and spent its force against a tree-trunk. There was no explosion, and nothing happened, which was something of a miracle; but what impressed me was that these four men stood still, not from courage, but because they were frozen with fear!
"A SWIFT, HEAVY CAR WAS PLUNGING TOWARD THE OPEN DOOR."
While there is danger in every step of dynamite manufacture, it appears that the center of peril is in the nitrating-house, where the fresh glycerin is mixed with nitric acid, or, more correctly, is nitrated by it. This operation takes place in a great covered vat about which are many pipes and stop-cocks. A man stands here like an engineer at the throttle, watching his thermometer and letting in fresh glycerin. These are his two duties, and upon the right performance of them depends the safety of the works. Every hour he must let in some seven hundred pounds of glycerin upon the deadly acid, and every hour he must draw off some fifteen hundred pounds of nitroglycerin and let it go splashing away in a yellowish stream down the long, uncovered trough that leads to the separating-house yonder. From this separating-house runs another trough to the freezing-house, and a third to the distant mixing-house. These three troughs inclose an oblong space, at the corners of which stand the nitrating-house, the separating-house, and the freezing-house. In each one of these, at any hour of the day, is a wagon-load of pure nitroglycerin, while in the three troughs are little rivers of nitroglycerin always flowing.
The arrangement of buildings in this part of the works makes clearer what was done at the nitrating-house by a certain Joshua Plumstead in the recent explosion. Joshua is a veteran at dynamite-making. He has worked at the nitrating-vat for twenty-five years, and has probably made more nitroglycerin than any one man in the world. He has been through all the great explosions; he has seen many men killed; he has stood by time and again when his own nitrating-vat has taken fire; and yet he always comes through safely. They say there is no man like Joshua for nerve and judgment when the demons of gas and fire begin to play.