The man and the thermometer in one of the nitrating houses

Dynamite consists merely of liquid nitroglycerin which has been absorbed by some porous material. The liquid was discovered by Sobrero, an Italian, in 1846. Its transport and use were attended with such danger, however, that the late Alfred Nobel conceived, in 1867, the plan of absorbing it in some non-explosive medium. After experimenting with saw-dust, brick-dust, charcoal, paper, rags, and kieselguhr, he finally settled upon the last named as the best material.

Kieselguhr, known in the factory as "guhr," is a silicious earth, mainly composed of the skeletons of mosses and microscopic diatoms, which is found as a slaty black peat in Scotland, Germany and Italy. Before being used it goes to the guhr-mill, where it is calcined in a large kiln, rolled, and sifted, the result being a very light pink powder of the consistency of flour.

In the house you have entered, twenty-five pounds of kieselguhr, with one pound of carbonate of ammonia, are weighed into a wooden box about three feet square and eighteen inches deep. Upon it is drawn seventy-five pounds of nitroglycerin from the filter tank by a man in scarlet. Another man in scarlet, with his arms bare to the shoulders takes the box to a table, and gives it a preliminary mix, to see that all the nitroglycerin is roughly absorbed. Then a man in blue seizes it, places it with other boxes on his hand-car or bogie, and pushes the load off to the mixing houses.

A Disastrous Explosion – The Mixing Houses
At half-past six on the morning of the 24^th February, one week after the writer’s visit to this house, it was the scene of a very disastrous explosion. Twenty-four hundred pounds of nitroglycerin was collected here, in the tanks and boxes mentioned, and from some cause which may never be known it exploded, killing six people – a chemist, a foreman, and four workmen.

A few other employees were slightly hurt by flying debris. The sound of course was tremendous, and the effects of the explosion, which were very clear in Irvine, three and one half miles away, are said to have been so strong in a town ten miles away that the gas lamps were extinguished by the air concussion. A disaster such as this, whose suddenness is not its least painful characteristic, cannot of course be minimized in its tragic importance.

At the same time, it serves as the best possible testimony to the value of the system of protection employed, That over a ton of nitroglycerin can explode in the heart of a factory where 1,300 people are at work, and only six men, within a few feet of it, lose their lives, shows better than any other evidence the meaning and value of the Ardeer mounds.

You follow the box to a mixing house, this, in the case of dynamite, is a large wooden cabin, containing a long narrow table on each side. In it six girls are at work. The runner sets the open box of the mixture down in the doorway. A girl hoists it to a table, and flies at it with bare arms as if it contained flour and water.

She mixes it thoroughly. Then she takes a big wooden scoop, jabs it into the box, and dumps the scoopful into a raised box of the same size, with a brass sieve bottom. She then, as if the sieve bottom were a washing-board, rubs the dynamite with all her strength against the sieve, forcing it through the small holes. A few of the girls use a leather hand-flap to rub with, but most of them prefer their bare hands.

You view the process with consternation. Hitherto you have looked upon dynamite as something to be regarded politely from a safe distance as if it were a rattle-snake. The girls handle it, however, as coolly as if it were the sand on the floor. Some of it is continually split, of course, and mixes with this sand, but the sand is all removed at short intervals and buried.

One of the few fatal accidents in the history of Ardeer took place near this house. A cartridge hut wherein four girls were working exploded, killing the girls. Burning dust from this hut fell into open boxes of dynamite in three other huts. The dynamite began to blaze, and deadly smoke from it, which consists of hyponitric-acid fumes, immediately filled the huts. Two girls in each had the courage to jump over the blazing boxes, and escaped; but the others, six in number, were suffocated in a few minutes. Thus ten persons lost their lives.

When the huts were entered, the six girls were found seated in perfectly natural attitudes, their faces showing no trace of agony or fear. It was evident that, having been stunned by the sudden explosion, they had suffocated before recovering from the shock. It will be noted that the loose dynamite burned and did not explode. This is one of several curious facts concerning dynamite which will be considered later.

It may be well to state at this point that the two hundred and odd young ladies employed in this dangerous work are all strictly beautiful. Everybody who visits the factory admits this at once. Nobody, in fact, seems inclined to invidious comparisons among strong and courageous girls, when each of them has enough dynamite in her possession to blow a hole in Scotland. Moreover, there is some reason for the statement.

The breathing of nitroglycerin by the workers gives them a universal clearness of skin, and among the fairer girls the contrast of scarlet and white in their faces is most unusual. You learn that (perhaps in consequence of their complexions) the girls marry quickly after entering the factory.