The PROCEEDINGS of the Naval Institute contain the very best and most valuable professional works on all subjects, and the writer in submitting this plain story of our smokeless powder hopes that it may find a place in our service publication. That it may interest many officers and place on record before the service the development of our present powder before the progress and the men responsible for it are forgotten is the raison d' 'etre of this article. The names of many of the men connected with this development are not generally known to the service but the navy is justly proud of their work and should give due credit to them by acknowledging and placing their achievements in our PROCEEDINGS. The building by the navy of one of the finest powder plants in the world without a single accident to its employees or product is surely a feat for the navy to be proud of. Compare our results with those obtained in France and we see how high we stand, for there M. Vielle, the French chemist and the inventor of nitrocellulose powder, probably the greatest explosive chemist in the world, although in charge of the government plants, has yet seen two fearful disasters take place in his navy, both of which were due to improperly manufactured powder.
Most of us do not know the men who have placed our navy in its powder manufacture on such a high plane. We do know that the French disasters occurred because their government factories were controlled entirely politically, so much so that not even an officer's inspection of the manufacture was allowed, and yet no one who has been acquainted with their service and their naval officers can have the slightest doubt that, if the same opportunity had been afforded them, the results would have equalled ours.
The adverse criticisms of our powder that appear frequently in various publications have never yet been based on fact or expert knowledge, there has always been some ulterior motive in them or some axe to grind. The record of our powder speaks for itself and whatever may be said of it by foreign critics—one can hardly call them disinterested either—it is not and never has been similar to Poudre B1 of the French with which it is continually and very erroneously being compared to its detriment.2 We do not claim the powder was as good at the start as it is now, for improvements in the manufacturing methods and chemical structure of it are continuing daily.
If we exclude Greek fire, which by an addition of saltpeter was made explosive at a very early and uncertain date, there existed from the 14th century to the i8th century but one explosive, black powder.3 M. Bertholet, a French chemist, toward the end of the 18th century made the first steps towards a new explosive when he prepared potassium chlorate and endeavored to apply its extraordinary oxidizing property in the manufacture of explosives; but his researches yielded no results and ended on account of severe explosions.4 Next came investigations upon the actions of concentrated nitric acid on starch, wood, cotton, and other organic compounds; the most prominent men in this field—which, however, bore no real results—were Braconnet, Pelouse and Dumas.
Detonators and percussion caps were developed through the discovery of mercury fulminate by Howard in the year 1799. This substance has the chemical formula Hg(CNO)2 and is prepared by a solution of mercury in nitric acid being treated with alcohol. The manufacture of fulminates was taken up by Liebig and Gay Lussac, and the compound was used as early as 1815 by an English gun maker, Joseph Egg, as caps for small firearms.
1See U. S. NAVAL INSTITUTE PROCEEDINGS, Vol. 37, No. 140, p. 1281, for detailed comparison of powders.
2See U. S. NAVAL INSTITUTE PROCEEDINGS, Vol. 38, NO. 141, p. 133, for a detailed answer to the most common criticisms.
3Black powder is still extensively used in certain types of blasting work and has a large sale for sporting powders, it being much cheaper than smokeless. Its accepted composition to-day is 74 per cent saltpeter, 15.6 per cent charcoal, 10.3 per cent sulphur; the moisture in the powder after drying generally remains at least .6 per cent.
4For much of the data in this article I am indebted to a lecture given by Prof. W. Will some years ago.
Between 1840 and 1850 occurred the investigation that revolutionized the explosive industry, and resulted in the discovery of nitrocellulose by Christian Friedrich Schonbein, and the preparation of nitroglycerine by Ascanio Sobrero at Turin.
C. F. Schonbein, in Basel, discovered in 1846 in his experiments on the oxidizing effect of sulphuric and nitric acid, the fact that, when cotton is dipped in such a mixture, a remarkable reaction takes place, wherein the outer appearance of the cotton has not been at all changed. It shows the same appearance, the same structure as before dipping in the acid mixture, but its chemical properties are entirely changed. The substance previously so tame, has suddenly become an eminently explosive compound.
Prof. R. Bottcher, who had also discovered an explosive cotton while engaged in similar experiments at Frankfort am Main, joined with Schonbein on October 5, 1846, and published the process for the preparation of guncotton. In other words Schonbein is the discoverer of nitrocellulose. Soon guncotton was tested in England at Woolwich Arsenal, under the influence of F. Abel, and its manufacture on a large scale was undertaken by the firm of John Hall & Sons at Faversham; and scientific experiments took place by a special commission of the German confederation to which, among others, the Austrian lieutenant, von Lenk, belonged, and which was assisted by Liebig as scientific expert. Large rewards were promised in case guncotton should show itself a substitute for black powder.
The English investigations ended suddenly in 1847 in consequence of the explosion of the still unfinished factory at Faversham. In 1848 there also occurred in France big explosions at Le Bouchet and Vincennes, terrible reminders that one must not underestimate the dangers which were involved in the manufacture of the new explosive.
The Austrian government bought the process from the discoverers and continued experiments in Vienna Neustadt under von Lenk. He improved the manufacture in many respects. He boiled the cotton, previously spun into yarn for more ease in handling, with potash solution for complete removal of the fat, he introduced a very thorough washing of the nitrated product in running water lasting several weeks, then treated it with a warm soap solution, and finally moistened it with water glass (sodium silicate) solution. This was to increase its stability through the alkali carbonate formed by contact with the air, and to give a denser, more slowly burning nitrocellulose through an inclusion of incombustible silica in the pores.
Lenk's cotton enjoyed a reputation for some time of being a sufficiently stable product, so that in the beginning of the '60's nothing appeared to hinder a general application of guncotton. But the overcoming of the other difficulties, especially in its ballistic application, proved greater than had formerly been supposed. The guncotton burned so rapidly in the barrels that the weapons were damaged or burst.
In spite of many a preliminary treatment by spinning the nitrated fibers into strings and cords, the combustion could not be controlled in the necessary way. So, when in 1862 the explosion of a guncotton magazine in Siemering Heath occurred, and in 1865 the explosion of a second magazine on the Steinfelder Heath, near Vienna Neustadt, both of which were ascribed to a spontaneous ignition of the guncotton, the manufacture of guncotton came to an end also in Austria.
But, in the meantime in England, under Frederic Abel's supervision, experiments were carried on diligently. Abel came to the conclusion that the objections which had led to giving up the work on the continent were exaggerated and that the unfavorable judgment in regard to the stability of Lenk's cotton was not justified. He carried out similar experiments to Lenk's and found that such purified guncotton answered all necessary demands in regard to stability. He improved methods for controlling the velocity of the explosion by pulping the nitrocellulose thoroughly in a pulping machine and then compressing it under great pressure.
This pulping process formed the key to the solution of the manufacture of stable guncotton, and thus modern guncotton really dates from the year 1865. Abel also introduced the granulation of the pasty mass with a small amount of binding substance in a vessel with swinging motion, and in 1865 he protected by patents the use of a mixture of soluble and insoluble nitrocellulose with the addition of solvents such as ether alcohol as a binding agent for the preparation of solid, that is, gelatinized, masses. It is unknown whether he carried out the process at this time.
In order to use this new explosive it was necessary to develop primers and fuses to ignite it and thus obtain the benefit of its properties. Their development came about indirectly through the discovery of nitroglycerine by A. Sobrero, of Turin, in the year 1846. This substance is the product of the action of nitric and sulphuric acids on glycerine.5 Immediately on the discovery of this compound he noted the terrible explosive effects on striking or heating it.
Nitroglycerine had been known for 20 years without other than a medicinal application until about 1860, when A. Nobel, of Stockholm, began his experiments in applying its energy for explosive purposes. He was engaged in developing a good blasting material. In 1864 he had tried to increase the effect of the simple fuse by a slight addition, that of an initial charge of quickly burning black powder. He finally, in 1867, found the solution by using mercury fulminate igniting caps for detonating nitroglycerine. He was the first one to show that this substance can detonate other substances.
It was this discovery of Nobel's which released for use in blasting, and other explosive uses, a whole series of explosive compounds.
It is said that A. Nobel by accident hit upon the mixture known as dynamite. He was shipping nitroglycerine in sheet iron canisters, which, to be protected from shock or blow, were packed in a bed of kieselguhr. One of these packages leaked and the nitroglycerine oozed out into the kieselguhr. This attracted Nobel's attention to the remarkable absorptive power of this earth. He found that with a content of about 75 per cent nitroglycerine a plastic mass is obtained which is much less sensitive to shock or blow than nitroglycerine, and in consequence of its plastic nature is exactly fitted to the manufacture of cartridges, which can be easily fitted into drill holes. The manufacture of nitroglycerine then grew up enormously. In 1861 it was first manufactured by Nobel on a commercial basis in the vicinity of Stockholm. In 1865 A. Nobel started the famous nitroglycerine factory at Krummel on the Elbe, which is still the largest factory on the continent.
Edwin O. Brown, a co-worker with Abel, and second chemist of the English war ministry, showed soon after that Abel's guncotton products could be brought to detonation in the same way.
Besides dynamite, guncotton here came into extensive use, after Brown had shown that it would give a complete detonation even in a wet condition with an initial charge of dry guncotton.
5See Explosives, Brunswig, by Munroe and Kibler.
In 1866 the manufacture of nitroglycerine was prohibited by Belgium, Sweden, Denmark and England; but this prohibition was quickly repealed as the safety of dynamite began to be proved.
To show the rapidity with which dynamite became common it is instructive to state that its manufacture in 1867 was but 11 tons, while in 1874 it was 3000 tons, and that now 2,000,000 tons are made yearly.
To develop a powder for ballistic purposes was the next problem. In 1860 the English captain, Noble, introduced the crusher gage for the measurement of powder pressure. The first actual successful steps towards the development of a smokeless powder according to modern ideas were first, the invention of the E. C. powder by Reid and Johnson in 1882, and next, that of the J. B. powder by Judson and Borland. The present smokeless powder industry, however, only dates-from the manufacture of the poudre B by P. Vielle in 1886, and of ballistite by F. Nobel in 1888. Vielle discovered in the gelatinization of nitrocellulose a method for the satisfactory regulation of its velocity of combustion. The English cordite is a modification of Nobel's ballistite. Vielle's powder is a single base powder of nitrocellulose, while ballistite has the two bases, nitroglycerine and guncotton.
The foregoing notes have served to trace the events in the discovery. and development of a smokeless propellant, the advantages of which from a military standpoint are so great that the problem of finding a stable progressive smokeless powder for the use of our navy became urgent, and our Navy Department therefore undertook its solution. Our guncotton factory at the Torpedo Station in Newport had been set in operation in March, 1884. The smokeless powder plant there was really started from saucepans and mortars used in researches in the laboratory of Prof. Charles E. Munroe, who had joined the Torpedo Station in 1886. Actual powder manufacture, the outgrowth of these experiments, seems to have been formally established by B. F. Tracy, Secretary of the Navy, in 1890, when manufacture of indurite was first begun, and the guncotton and powder manufacture were consolidated under one head. At this date we find on duty there the following prominent chemists who are primarily responsible for the successful results obtained in our navy with smokeless powder: Prof. C. E. Munroe, then in charge with G. W. Patterson as his senior assistant; also Mr. Tobin, who later became the head chemist of the station. When Professor Munroe left the station in 1892 H. F. Brown was appointed as his successor.
The result of Munroe's experiments was the propellant known as indurite manufactured in 1891, which was a single base powder, the first example of such in the art, made from a specially purified high nitration guncotton colloided with mono-nitrobenzene, which substance is known commercially as oil of mirbane. By indurating this plastic mass the colloiding agent was removed. Samples of this indurite made in 1891 are perfectly stable to-day.
A process and the necessary machinery were then developed for producing indurite, which was used experimentally in guns up to and including our 6-inch. This substance was not experimented with after Prof. Munroe's departure from Newport, due to several cases of instability in samples which led his successors into other lines of research. Upon Prof. Munroe's detachment a naval officer was placed in direct charge of the factory.
A single base powder of guncotton, barium and potassium nitrates, and acetone, was next produced, but this was, on account of its brittleness, superseded by a product corresponding to the French powder that was then being manufactured for sale, and is similar to that used in their navy at present, in that it contains two types of nitrocellulose. This contained soluble and insoluble nitrocellulose, barium and potassium nitrates, and was colloided at first with acetone but afterwards with ether alcohol. Patents were taken out on this powder in 1895 by Commander G. A. Converse, U. S. N., and Lieutenant J. B. Bernadou, U. S. N., who were both then on duty at the Torpedo Station, the latter officer being an excellent Russian scholar and the translator of a valuable work by Mendeléef on powder. In the summer of 1895 Lieutenant Bernadou gave to Mr. Patterson a small sample of powder which he had obtained from Russia and which represented the type of powder in use there at that time. The analysis by Patterson showed the powder to be composed solely of a soluble nitrocellulose—quite different, it is to be noted, from the mixture of the two grades of the nitrocellulose then and still used in the French powder—colloided with ether alcohol. Its nitration was found to be about 12.45 per cent. Experiments commenced in November, 1895, resulted in the discovery early in 1896 by Patterson of the mixture of acids necessary to produce the desired result. This year, 1896, then is the date of the adoption of our present powder. The composition of the powder is based on the results of the work by the Russian chemist, Mendeléef, who deduced a theoretical per cent of nitration for the nitrocellulose required to obtain the greatest gas volume under ballistic conditions, calling it 12.44. The chemical formula given for it is this (C30H38(NO2)12O25) which upon being exploded in a gun breaks down into (3OCO+19H2O+12N).
Practically there have been found the following differences in velocity due to the various percentages of nitration: in a 7"/45 gun it requires 65.8 pounds of powder of 12.29 per cent nitration to give the same velocity as 60 pounds having a nitration of 12.77 per cent; in a 6"/40 gun 25.8 pounds of powder at 12.57 per cent nitration equalled 23.6 pounds at 12.80 per cent; and 343 pounds of nitration of 12.35 per cent in 12"/40 gun give the same velocity as 314 pounds of 12.65 per cent nitration.
At this point it might be well also to answer a question frequently heard in the service as to just what the gases of an explosion contain. A complex series of gases is to be found due to the volatiles and rate of burning in a gun. Quick powders, i. e., those that are entirely consumed before the projectile leaves the gun, give a faint white smoke and high chamber pressures; while slow powders, i. e., those that are not burned by the time the projectile leaves the gun, usually give orange colored smoke, pungent odors and low chamber pressures. The higher the pressure the more nearly the conditions of the theoretical equation of Mendeléef's are reached. At full muzzle velocities we now find carbon dioxide, carbon monoxide, nitrogen, hydrogen, steam, marsh gas, and traces of ammonia and cyanogen compounds.
The maintenance of gas pressure in the bore of guns is shown in the diagram herewith that has been made from actual results obtained in firing black, brown, and smokeless powders, and which gives graphically the reason that we use smokeless powder and are enabled to reach the modern high velocities.
The present form of powder grain was not the first type tried by any means and much experimentation has taken place for years along the line of developing the most suitable granulation for powder. Amongst other forms a grain with 18 perforations was once in use. The present multi-perforated smokeless powder grain, a cylinder with seven longitudinal holes, was designed by Maxim and Schupphaus, and the patent was sold by them to the Du Pont Company, who gave it to the navy.
(“Travel of Shell in Calibers” diagram not replicated in this Word document.)
Lieutenant Bernadou, with the head chemist at Newport, H. F. Brown, after the proper mixture of acids had been determined in the laboratory by Patterson, developed a method for the manufacture of this powder on a large scale based on the laboratory results, which method showed the practicability of duplicating the Russian type of powder. That is the smokeless powder now in use not only in our navy but also in our army.
In 1895 there were three private explosive plants all operating independently in which the manufacture of such a powder was feasible. These plants were the Laflin & Rand Works at Haskell, New Jersey; the Du Pont Works at Carney's Point, New Jersey; and one concern on the west coast known as the California Powder Works, which manufactured its nitrocellulose at Pinole, and the remaining portion of its powder at Santa Cruz, the nitrocellulose from Pinole being shipped there. These companies differed widely in their machinery and methods but all undertook the contracts for powder, the specifications for which were based on the abovementioned Newport laboratory work.
The first powder delivered by a private firm was proved in June, 1897, and was made at the Carney's Point plant, the powder being designated as S. P. 3. The California Powder Works in July, 1898, had its first product known as S. P. 7 proven, and similarly the Haskell plant had its first proven in May, 1899, known as S. P. 34.
The Bureau of Ordnance decided in September, 1897, to build a powder plant, and under date of September 28, Lieutenant Commander T. C. McLean, U. S. N., inspector in charge of the Torpedo Station, appointed a board consisting of Lieutenant Kossuth Niles, U. S. N., H. F. Brown, Karl Hedberg, and Frederick Kniffen, to prepare plans and specifications for a factory having a capacity of1000 pounds per day. These plans were submitted on March 31, 1898, and specifications were given on April 20, 1898. In July, 1898, Congress made available the funds for the erection of a navy factory to be located at Indian Head, Maryland, this point being about 20 miles below Washington on the Potomac River and Mattawoman Creek, it then being the site of our ordnance proving ground.
Shortly thereafter Lieutenant Bernadou was ordered to the Bureau to revise these plans and start the work at Indian Head. Patterson was chosen chief chemist at the Indian Head plant in July, 1899, by a board consisting of Captain Couden, Lieutenant Bernadou and Brown. In the face of great obstacles Captain A. R. Couden and Mr. G. W. Patterson started the work at Indian Head and evolved the present splendid powder-making plant. The first completed powder grain was run out on June 28, 1900, Lieutenant Joseph Strauss being then in charge of the factory. It was a gnarled and spotted grain, a great contrast to the beautiful clear, translucent grains of the present day, but still it marked the fact that at last we possessed a working powder factory. The first completed index of powder made at Indian Head was known as S. P. 148 and this was proved in February, 1901.
A fourth private plant was built at about this same time (1900) at Parlin, New Jersey, and it was known as the International Smokeless Powder and Chemical Company. This company obtained its supervising force from men at the Torpedo Station, where they had been trained in the investigations, developments and machinery necessary to produce powder. The company obtained contracts from the Navy Department by underbidding the other three private firms by one cent per pound. The first index of powder delivered by them was known as S. P. 199 and was proved in April, 1902. Its success in a great measure was due to the energy and skill of Mr. C. F. Burnside, who is now with the Du Pont Company.
It is thus seen that four firms started in to manufacture cannon powder shortly after the beginning was made by our own government plant at Newport, which plant had delivered the navy's first index of smokeless powder in season to be proved in March, 1896. The Navy Department gradually transferred its powder manufacture to the Indian Head plant and none is now made at Newport.
This powder developed by Patterson from the sample given him by Lieutenant Bernadou, and made commercially practicable by H. F. Brown and the two men just mentioned, was continually improved upon by them and by the personnel of the private plants, which had reached corresponding results and details of manufacture independently after being asked to undertake the work.
The success and cheapening of the manufactured product is traceable in a large degree to a few individuals and the ones most prominent in contributing to the results deserve to be known in the service. It must be borne in mind that the private firms have contributed in a very large degree to the development of powder in this country and more particularly so after their consolidation under one technical head. H. F. Brown, who had some years before left the Newport plant to develop the Parlin plant, was given this technical direction of the four companies mentioned previously in the year 1904.
The dehydration process by which the water remaining in the nitrocellulose after its washings is displaced by alcohol and the excess alcohol then squeezed out in a hydraulic press—one of the basic operations in manufacture—was brought about by Francis G. Du Pont and applied by him at Carney's Point in 1897. The combination of these two processes into the one receptacle was worked out by W. C. Peyton at the California Powder Works. These two men appear to deserve also equal credit for the solvent recovery process by which during the drying of the finished powder a large proportion of the ether and alcohol used in colloiding it is reclaimed, purified and used again in manufacture, as they really developed the same operation independently of one another though practically at the same time. Francis I. Du Pont, at Carney's Point, produced the Du Pont nitrometer for the nitrogen determinations, which instrument has been a great laboratory help. At the California plant Robert Robertson was the great factor in progressive development and improvement, as was H. C. Aspinwall similarly at the Haskell powder plant.
The Indian Head plant is still under the skilful direction of G. W. Patterson, its first head chemist, who has proven to be not only a chemist but a mechanical engineer of much ability. The design of its dehydration, macaroni and finishing presses can be attributed more to W. C. Peyton than to any other one person. The success of our government plant in great measure is directly traceable also to Rear Admiral Joseph Strauss, who from the start initiated and forced to completion valuable and essential improvements and has always stood as its sponsor in all its progressive development. The present sulphuric acid plant which practically makes the navy independent of privately controlled sources of supply is but one of his achievements there. This sulphuric acid plant succeeded in making acid at about $0.0065 per pound or about 65 per cent of the market price when that plant was built. The mixed acid made costs $0.032 per pound as against $0.035. The only supplies now purchased by our navy factory are the Tennessee fiber cotton, the sodium nitrate (Na NO 3) from the Atacama and Tarapaca provinces of Chili, where it is found in layers one to five yards deep, the alcohol, and the sulphur. To manufacture a pound of powder now requires approximately .67 pound of cotton, 3.14 pounds of mixed acid, and .75 pound of alcohol. The soda nitrate is used for the manufacture of nitric acid and the sulphur for the sulphuric acid.
Most radical improvements in the various steps required in the manufacture of smokeless powder both as regards the materials and the machinery used are constantly occurring. For the cellulose several materials have been experimented with, these being cotton waste, cotton rags, long and short fiber cottons. The purification and preparation of these various types have been ever to the one end of getting a better product finally. At the present time a specially grown, treated, and purified Tennessee short fiber cotton forms the cellulose. The ether, the alcohol, the soda nitrate, and the acids are the very best that science can produce, as is likewise the water, of which 75 gallons are used for every pound of finished powder.
The Du Pont Company has just invented a new improved method of nitrating cotton and their plants have a capacity of 35,000 pounds per day of nitrocellulose. This process is now to be installed at our Indian Head plant, the plans therefor having been furnished by the Du Ponts.
For many years our powder was an absolutely pure nitrocellulose colloid but the necessity of having the many people under whose care it was placed from time to time familiar with its stability led to an endeavor to put stability indicators into powders. Rosaniline, which colored the powder a brilliant red, was introduced at Indian Head by Patterson in 1902, incorporated in 1907, and was a success there, but was abandoned because the different plants manufacturing powder for the navy did not turn out a product uniform in color, due partly to their water and partly to their storage of the rosaniline in copper instead of galvanized tins. This rosaniline has held up remarkably well in all Indian Head powders and has proved to be just what it was intended to be, a stability indicator. The first incipient decomposition fades the color entirely away. No rosaniline powder made at Indian Head has been withdrawn from service.
The early days of nitrocellulose powder were attended with many setbacks, lack of stability6 oftentimes developing from causes not easy to ascertain. The waste due to this cause led us to make strenuous efforts to utilize the unstable and doubtful powders as well as to determine how to make powder so stable that it would never decompose. A method of reworking powder was discovered in 1905 by the Du Pont Company at Carney's Point and after a successful demonstration the process was given to the navy. The navy contributed essentially to the discovery of this reworking process as Patterson successfully applied the dehydration part at Indian Head although Carney's Point had been unable to do this. S. P. 143, a 3"/50 powder, was the one tried and reworked from March to May, 1906. In this case it was remade into a 7" powder and proved excellent. This reworked product is uniformly opaque instead of being translucent as in the case of the new product.
As showing the need that this process supplied it is well to state that in the year ending July, 1913, there were 965,000 pounds of this reworked powder made. In that same year our factory turned out 1,800,000 pounds of new powder and at present date, January, 1914, is making 11,000 pounds per diem.
Because of the long period consumed in drying the powder, thereby causing a delay in the use of powder until practically four months after its manufacture, much energy has been devoted to shortening this drying process. The time has been shortened somewhat but all quick methods of drying have proven unsatisfactory to the Navy Department.
A method of water-drying promised well in 1903 but experience with it showed that the grains were unevenly dried and that the per cent of volatiles could not be predicted with uniformity. Raising the temperature very high for short periods while it hastened the drying had a marked deteriorating effect. The system of moderate temperatures and drying in closed circuit dry houses has proven the best method. At one of the German factories 122° F. is attained gradually in drying but our experience shows this to be a mistake as incipient decomposition is generally started. The Du Ponts having successfully dried several lots of powder at 55° C. still are in favor of increasing the temperature of drying.
6See U. S. NAVAL INSTITUTE PROCEEDINGS, Whole No. 136, Vol. 36, No. 4, December, 1910, p. 929, where Commander Strauss discusses the stability question in detail in an article entitled "The Stability of Smokeless Powder.”
The uniformity in size, shape, and density of grains continued with great rapidity and these qualities that are so essential to uniform ballistics in the powder have reached a high state of perfection.
In 1909 after much discussion for and against, it was decided to incorporate an organic compound with the powder as a stabilizer. There had been many such used in various countries such as urea, amyl-alcohol, nitro-guanadine, and diphenylamine, but reliable reports as to their actual value could not be obtained. The substance chosen as a result of a European trip made by H. F. Brown in 1898 and sample lots made by the Du Ponts in October was diphenylamine NH(C6H5)2, and the first lot of powder with which that was incorporated was turned out in July, 1909, at our factory and shipped to Olongapo, where it could be subjected to the very worst conditions of storage. The private companies have used it since November, 1908, in all the powder made by them for the government. This experiment has proven a success in every way, all indices thus manufactured being as stable now as when first made. This substance is a basic compound and is a pale yellow solid, it is soluble in alcohol, benzene, or ether and is obtained by heating aniline with aniline hydrochloride at from 250° to 260°. This substance absorbs nitrous vapors readily and thus prevents the generation of more. This action should thus make powder indefinitely stable. Indian Head powder with this substance is still bright and clear, although that from the private companies is slightly darker and opaque as a rule. This difference in color seems more due to the water used in manufacture than to any other cause. All diphenylamine powders are yellower, particularly around the edges and perforations, than is powder that does not contain it.
Our Ordnance Bureau in 1908 started a testing station for powders in the Philippines which has resulted in keeping powder there in a very satisfactory state, and also has proven many interesting facts, among them being that moisture and varying temperatures in storage are the worst enemies of powder.
Stabillite was an invention of Hudson-Maxim that was sold to the Du Pont Company and by them communicated to the navy. It is a smokeless powder made with non-volatile solvent and is ready for use immediately after granulation, and as such may have a valuable military use in war.
The English cordite, originally made with 53 per cent nitroglycerine, has now been reduced so as to contain but 23 per cent of nitroglycerine, and there is every reason to believe that this cordite would be abandoned for our nitrocellulose powder if it were not for the fact that its adoption would cause such an enormous change in ordnance material that the resulting expense would be beside the question.
The high explosive industry was started by Herman Sprengel,7 who observed that every compound capable of internal combustion and every mixture of oxidizing and combustible components can, under the influence of a detonator, be brought to decompose. He started his experiments in 1873 by directing the attention of the explosive industries to picric acid. This had been used only as a dye, but now, so great has become the need for it, its manufacture is in the hundreds of thousands of pounds per year. It is manufactured by the nitration of carbolic acid. The various safety explosives for mines have been on the market since 1886 and Sprengel was the most prominent person in their development. That mining with the safety explosives has become comparatively safe is shown by the fact that in Prussia one death is now caused by the use of each 11,000,000 tons of explosive, whereas in 1895 it was one to every 539,000 tons used.
All navies have experimented with shell fillers, torpedo and mine charges of high explosives. Our service uses Explosive D for shell-burster charges, and this explosive, which was developed by Major B. W. Dunn, U. S. A., has given better results than any of the very numerous shell fillers experimented with up to date. This explosive is perfectly safe to handle, keeping it away from lead salts only, is unaffected by a temperature of as high as 190° continued for a period of 120 days. It is manufactured for both services by the Semet Solvay Company of Syracuse, New York.
For mine and torpedo charges TNT, exhaustively treated of in the PROCEEDINGS for June, 1913, page 721, is forging to the fore and bids fair to be soon substituted for our wet and dry guncotton therein. We have been fortunate of late in having a really successful detonating fuse developed that is perfectly safe under all conditions of handling and stowage. Details regarding this and Explosive D are of course held as confidential, though each officer who desires to learn more of them than it is proper to give here may do so through our Bureau of Ordnance.
7Explosives, Brunswig: Trans. by Munroe and Kibler.
The foregoing pages have briefly brought out the persons and the events connected the most intimately with the production of our modern navy explosives, and I trust that the main credit has been properly placed. Our service must also bear in mind that each successive inspector of ordnance in charge at Indian Head in conjunction with the powder expert, G. W. Patterson, is primarily responsible for the superb quality of our powder to-day. The quality of the product of our factory is now at least equal to any powder manufactured anywhere. We must accord great credit also to the co-operation of the chemists and the superintendents of the Du Pont Company, several of whom as noted, were trained in the powder business in the early days at Newport, as well as to the naval inspectors of powder who by study and observation have materially assisted in the continual improvement in the processes of the manufacture and the quality of the finished powder.