Inventors at Work, with Chapters on Discovery

by George Iles

Alfred Nobel and His Explosives.

It was in trying to make guns of a new strength that Sir Henry Bessemer entered the path which enabled him to make steel at little more cost than cast iron. It was in providing guns with explosives of new power that Alfred Nobel won both distinction and fortune. As in the case of Sir Henry Bessemer, his gifts have inured vastly more to the service of peace than of war. It is estimated that during the Civil War, 1861-65, more explosives were used in the United States by civil, railroad, mining and quarrying engineers than in the field of battle. Chief of these explosives was gunpowder; nitro-glycerine, though well known, had then little or no acceptance, for good reasons. How its defects were overcome is told by Mr. Henry de Mosenthal in an article on Alfred Nobel, in the Nineteenth Century Magazine, London, October, 1898. By the editor’s kind permission that article is here freely drawn upon.

Nitro-glycerine, discovered by Sobrero in 1847, is made by treating glycerine with a mixture of nitric and sulphuric acids; it is poisonous, very sensitive to a shock, and most dangerous to handle. Being liquid it runs into the fissures of rock when poured into a bore-hole, and requires to be carefully confined that it may explode when ignited by means of a simple fuse. Nobel tried to overcome these deficiencies, first by mixing the liquid with gunpowder, and then by adding fluids which rendered it non-explosive, so that it could be safely transported, the added liquid being removed just before use; he also suggested confining it in a tube having the shape of a bore-hole, and firing it by means of a small gunpowder cartridge or primer. But all this did not avail, and accidents occurred so frequently that the use of the blasting oil was prohibited in Belgium, in Sweden, and later on in England. A vessel carrying some cases shipped from Hamburg and bound for Chili was blown up, and the event caused such a sensation that it seemed as if the use of nitro-glycerine would be prohibited the world over. In the meantime, however, Nobel had solved the problem of its safe use, and at the end of 1866 he had invented a compound, which he called dynamite, made by mixing the nitro-glycerine oil with porous absorbing material, thus converting it into a paste. Dynamite proved on experiment to be comparatively insensitive to a shock or a blow; it burnt when ignited, and could be properly exploded only by means of a powerful detonator fixed to the end of the fuse and inserted into the plastic explosive.

The invention of dynamite marks an epoch in the history of civilization. In judging of the degrees of culture of a people, we are guided to a great extent by the kind of roads and waterways they have constructed, and by the facility with which they have obtained metals and applied them to the arts. The Romans constructed excellent roads on the level, but in the mountains they could only make narrow and very steep paths. Canals and cuttings were made with great sacrifice and labor, and only where the soil was soft. Thus Suetonius states that in order to make a cutting about three miles long to drain the Lacus Fucinus, the Emperor Claudius employed 30,000 men for eleven years. In the sixteenth century road making and mining were scarcely more advanced. It took 150 years, ending with 1685, to mine five miles of gallery in the Hartz mountains. Although blasting with gunpowder dates back to the seventeenth century, it did not come into general use until about the middle of the eighteenth century, at which time the total cubage mined in Great Britain amounted to little more than of a large railway cutting at the present day. The use of gunpowder gave a great impetus to mining and public works, but it was only the introduction of railways, and the necessity of laying the lines on easy gradients, which raised blasting to a science. The introduction of dynamite, thrice as powerful as gunpowder and much more reliable, entirely revolutionized that science, and made it possible to execute the gigantic engineering works of our time, and brought about that prodigious development of the mining industry of the world which we have witnessed since 1870.

Nobel Profits by an Accident.

Dynamite is combined with twenty-five per cent. of inert matter as an absorbent; for this large proportion of unexploding substance, Nobel sought an active substitute. This, he thought, might be a substance which would dissolve in nitro-glycerine so as to form a homogenous paste. Now for a sagacious experiment with a liquid brought to his hand by accident. Whilst experimenting in search of such a material, he one day cut his finger and sent out for some collodion to form an artificial skin to protect the wound; having used a few drops for that purpose, it occurred to him to pour the remainder into some nitro-glycerine, and he thus discovered blasting glycerine, which he patented in December, 1875. Collodion is made by dissolving a gun-cotton in a volatile solvent, a mixture of ether and alcohol, and Nobel suggested that the viscous substance thus obtained should be mixed with the nitro-glycerine so as to form a jelly. On further experiment the jelly was dispensed with, and blasting gelatine was made, as it is now, by warming the nitro-glycerine, and adding about eight per cent. of a gun-cotton which was found to be soluble in nitro-glycerine. The new explosive, half as strong again as dynamite, was too violent to be applicable to any but the hardest rock. Nobel, however, discovered how to moderate its action, and gelatine dynamite and gelignite were manufactured by the addition of saltpetre and wood-meal to a blasting gelatine of less consistency than that employed without such admixture. Blasting gelatine was used in large quantities in the piercing of the St. Gothard tunnel, where the rock was so hard that no satisfactory work could be done without it. Since then the use of the gelatine explosives has increased more and more, and in some countries they have entirely superseded dynamite.

Nobel Invents Smokeless Powder.

The smokeless powder which Nobel originated was based on his discovery that by means of heated rollers he could incorporate with nitro-glycerine a very high percentage of that soluble nitro-cellulose, or gun cotton, which his factories were using in the manufacture of blasting gelatine. Blasting gelatine altered by means of moderating substances, had been tried in guns and had burst them. Nobel now found that if the nitrated cotton was increased from eight to about fifty per cent. he obtained a powder suitable for firearms. The progress in the construction of weapons, and especially the introduction of quick-firing guns, made it necessary to have smokeless powder, while higher velocities demanding straighter paths for projectiles could be attained with new arms resisting high pressure. Whilst in quest of such a powder, Nobel perfected several methods for regulating the pressure in guns, and modifying the recoil. It was in the beginning of 1888 that he invented his well-known smokeless powder, or ballistite. His discovery that the two most powerful shattering explosives, nitro-glycerine and gun-cotton, when mixed in about equal proportions, would form a slow burning powder, a propulsive agent with pressures which would exceed the resistance of modern weapons, caused astonishment in technical circles. Nobel submitted his powder to the British Explosive Committee, which found that instead of employing the variety of gun-cotton which is soluble in nitro-glycerine with the aid of heat, the insoluble kind could be used provided an assistant solvent could be added; and that the manufacture could be carried on at lower temperatures than those necessary in producing other explosives. The powder thus obtained was cordite, and this they recommended for adoption.

Nobel, Bodily Weak, was Strong in Mind and Will.

Physically weak, of nervous, high strung and exceptionally sensitive disposition, Nobel was endowed with a strong will, unbounded energy, and wonderful perseverance; he feared no danger and never yielded to adversity. Many would have succumbed under the misfortunes which befell him, but the succession of almost insurmountable difficulties, the explosion of his factory, causing a general scare and dread of the deadly compound he was making, the loss of his younger brother, to whom he was devotedly attached, the consequent paralysis of his father, and his mother’s grief and anxiety, could not deter him from pursuing his aim. His temerity frequently verged on foolhardiness, as when he was going to his father’s works one day at St. Petersburg, and finding no boat to take him across the river, he swam to the opposite bank of the Neva. The co-existence of impulsive daring with sensitive timidity was a striking feature in his character. He frequently demonstrated the value and safety of his explosives with his own hands, although he was particularly susceptible to headaches caused by bringing nitro-glycerine in contact with the skin; these headaches affected him so violently that he was often obliged to lie down on the ground in the mine or quarry in which he was experimenting. On one occasion when some dynamite could not be removed from a large cask he crept into it and dug the explosive out with a knife. Many other incidents could be related of the fearlessness he displayed when the success of his invention depended entirely upon his demonstrations of its safety, which in those days had not yet been thoroughly proved.