Page:McClure's Magazine v9 n3 to v10 no2.djvu/110

836 fulminate of mercury and various kinds of detonators. The explosive force of No. 1 dynamite, weight for weight, is four times that of gunpowder. Bulk for bulk, the dynamite being much heavier, it is over seven times as powerful as gunpowder. Blasting gelatin has nearly six times, weight for weight, and a fraction less than ten times, bulk for bulk, the power of gunpowder. Gun-cotton and No. 1 dynamite are about equal in explosive strength. Dynamite is not allowed on passenger trains in England, but is transported with great freedom on the Continent, and thirty thousand tons of it have been shipped on the English and Continental railways without accident up to date. Of course, every package and case carry explicit instructions, but that the danger is small the immunity from explosions in transport clearly shows.

The moral of which is, that dynamite is safe and blasting gelatin is safer if they are treated with only reasonable care. "The accidents do not occur here but in the use of it," says Mr. Johnston. "If the company's explicit printed instructions were followed, accidents would scarcely be known." Accidents often occur in thawing after an explosive has been frozen; but these arise from the incredible recklessness of miners. Small accidents, also, transpire at Ardeer in the repair of pipes. A drop of nitroglycerin which has secreted itself in a crack or crevice in the metal is sometimes struck by a hard tool, and costs a plumber one or more fingers.

These facts concerning dynamite are well known, and they are very reassuring. As you enter the train to leave Ardeer, however, the old habit of doubt reasserts itself. A bit of white fluff on your coat sleeve is viewed with the greatest suspicion. The question arises, "Is it cotton or gun-cotton?" Nerving yourself to the ordeal, you deliberately pick it off. You then carefully throw it out of the window to wreak its fell purpose, if it has one, on the landscape. Then you settle back with a vague desire to look at a thermometer. You have acquired a respect, an admiration, for any and all thermometers, which will abide with you to the end of your days.