Carl Auer, Freiherr von Welsbach
(1 Sep 1858 - 4 Aug 1929)
The Work of Dr. Carl Auer von Welsbach in the Field of Artificial Illuminants.
by Geo. S. Barrows.
Illuminating engineers, in order to properly pursue their vocation, must have some knowledge of all the various sources of artificial light, and beyond the necessary knowledge of these sources, their values and the methods of operating them, it is highly advisable that they be familiar as well with the history, development and production of these light sources, not only for their own enlightenment, but for the purpose of intelligently explaining to, and discussing with their clients the proper light to adopt and reasons therefor.
Among the few names indissolubly connected with the development of artificial illumination, that of Welsbach is prominent, and, as is proper, in view of his work, his name is generally used to define a certain system, one which in a way was old even before his birth, but which, in spite of the numerous attempts to perfect it commercially, was never considered seriously until he discovered the hitherto unknown properties of certain rare and even unknown substances, which, thanks to his inventive genius, he was able by novel methods to utilize in a manner that almost from the first was a commercial success.
The production of light by means of a body rendered incandescent by the heat of a gas flame, has been the goal of many inventors for over a century, all working on similar lines which differed only in detail, as to the kind of gas used (hydro-carbon, oxy-hydrogen, etc.), the substance to be heated (a refractory metal or oxide), the form of the body and manner of applying the flame. With the exception of the Drummond light, an oxy-hydrogen flame on a pencil of lime, none of the various lamps was more than evanescent, and even the Drummond light was limited in its application to such installations as could be given the constant supervision of an experienced operator. Several lamps, such as those of Sellon & Clamond, were in a way quite similar to the later invention of Welsbach, consisting of a bunsen burner surmounted by a foraminated hood of refractory material. The low efficiencies of these lamps, however, inherent in the imperfect hoods as constructed, prevented them from ever becoming a readily salable article.
It is probable that Welsbach had never heard of these lamps, except as a well read student of chemistry or physics would know of all such applications of the sciences in which he was particularly interested, and it is certain that he had not the slightest idea of the course that his discovery would cause him to follow, so that his quickness of perception and perseverance in the development stamp him as an unusual investigator, observer and inventor.
Dr. Carl Auer Baron von Welsbach, now a commander of the Imperial Austrian Order of Franz Joseph, corresponding member of the Imperial Academy of Sciences in Vienna, recipient of the Birmingham Medal, recipient of the gold Elliott-Cresson Medal of the Franklin Institrie du Gaz en France, honorary member of the Deutscher Verein von Gas und Wasserfachmannern, honorary member of the Incorporated Institute of Gas Engineers of England, honorary member of the American Gas Light Association, honorary citizen of many towns and parishes, was born September 1, 1858, the youngest son of Alois Ritter-Auer von Welsbach, a celebrated typographer and the director of the court and state printing office of Austria.
His chemical studies were pursued first at the University of Heidelberg under the celebrated Dr. Bunsen, and later under Professor Lieben at the University of Vienna.
In an address delivered by Dr. Welsbach before the Deutscher Verein von Gas und Wasserfachmannern in 1901, he gives an interesting account of his early work, from which we may abstract the following: About the year 1880, while a student in the University of Heidelberg, he was occupied with the chemistry of the rare earths, being particularly interested in the separation of didymium into its components—neodymium and praseodymium and the study of erbium-oxide.
It was the remarkable behavior of this latter rare substance and its glowing flame that particularly drew his attention, the peculiar striped spectrum when glowing being very unusual. The small beads gathered on a platinum loop not giving a sufficiently bright spectrum, it occurred to him that it might be possible to saturate a piece of cotton webbing with a solution of the salts, and then burn out the cotton, leaving the oxide of the earth. Much to his surprise, he found that this experiment was more than a success, for the earths retained the form of the webbing to an extent not considered possible by him.
His researches included many others of the rare earths, among them being lanthanum oxide, which, giving a more intense light than any of the other earths which he had used, first inspired him with the idea of using this material for lighting purposes.
The first mantles were not made in the form of the present mantles, but were produced by sewing a piece of relatively loose net webbing into a cylinder, and then saturating this cylinder in the desired salts. The first mantle made in this way from lanthanhm oxide was apparently perfect. but having occasion to be away from the laboratory for a few days, Welsbach was very much disappointed to find on his return that the mantle, which had been carefully put away, had crumbled to a powder. It was at this time that his skill as a chemist and perseverance as an inventor stood him in good stead. He immediately made up his mind to combine the lanthanum oxide, which had high light-emitting qualities, with another substance which would not slake and disintegrate so easily by absorbing water vapor or carbonic oxide from the air. Magnesia was decided on as being the best material known at the time, and from a mixture of lanthanum and magnesia a much better mantle than the first was made, which did not crumble to dust and which gave a fair light, but which, after a few days’ burning, lost its peculiar porous structure, becoming glassy and also shrinking badly.
This, while far in advance of the first mantle, was still a mere experiment, so it was necessary for him to go further, and his next experiments covered some of the zirconium oxides. These zirconium mantles gave very much better results, as they were somewhat more efficient, and retained their shape for a period of several hundred hours. Continuing his experiments with various earths, he was surprised to find an extraordinary increase in the intensity of the light when thorium oxide was added, and it was of these materials that the first commercial mantles were made in the laboratory of the University of Vienna and exhibited to the public in a lecture before the representatives of the Vienna press in January, 1886, the invention being introduced to the world and named by the editor of the Nuer Wienner Tageblatte the “Gasgluhlicht.”
These mantles were about 4 in. long, about a little less than 1 in. in diameter, and were made of cotton webbing sewed down the side, webbing of the proper size for mantles, at that time not being knitted. The burner was very awkward in appearance, having a very long bunsen tube and a very high chimney. Lamps of this description were the first commercial lamps placed on the market, and they were put out in practically every country of the world where manufactured gas was used, following the organization of companies in the various countries which had purchased the patent rights from Dr. Welsbach, he having applied simultaneously in the different countries for patents in the latter part of 1885 and during 1886. His first patents, a number of which were quite similar, claimed compounds for incandescent bodies, the different patents specifying different compounds, and also a lamp having a fabric of combustible textile material, impregnated with the particular salts specified in the patent. The efficiency of these lamps was from 10 to 15 candles to the cubic foot of gas, and the depreciation in candle-power was considerably greater than it is at the present time, although there are records of their early mantles burning for a period of over 20,000 consecutive hours, and giving at the end of that time an efficiency of nearly 10 candles to the cubic foot.
The next few years were, comparatively speaking, years of considerable commercial development in the line of the incandescent gas light, Dr. Welsbach being employed in directing the operations of his large chemical laboratory in Vienna, where the fluid for impregnation of the webs was made for all of the companies of the world. The burners at this time for all of the companies were made by the Pintsch Co. in Berlin. and it was not for several years that there was any change in this method of handling the general business of the incandescent gas light. About 1888, a fluid factory was started in this country, and at about the same time, burners for the different countries were manufactured to suit the particular requirements or tastes of the country in which they were used. With the exception of the United States, however, all of the various countries obtained their supply of fluid from the main fluid factory in Vienna. As may be well imagined, Dr. Welsbach was unable to give very much of his time to the perfection of the incandescent body, he being much absorbed in the organization and the operation of the various companies, which, while not directly associated with each other, were all closely in touch with Dr. Welsbach and the parent company in Vienna.
For several years the lamp had been more or less of a novelty, and so there was found some market for it, but after this novelty had worn off, and it was seen that the efficiency of the lamp was not sufficiently greater than that of other illuminating devices to pay in any great degree for the annoyances experienced by the breakage and shrinkage of the primitive mantles, the demand for the lamps fell off to some extent, and for some time the fortunes of all the incandescent companies were at a low ebb. Nearly all of the various companies were engaged in perfecting the methods of manufacture of the mantles and burners for use with the mantles, but none of them was devoting the proper attention to the improvement of the incandescent body, or mantle. This seemed to be more or less in Dr. Welsbach's particular province, and the conditions of affairs which then existed, spurred him on to further efforts to produce an incandescent body which would have a longer life, both physically and in illuminating value. The fabric base for the mantles at this time was all made on a stocking knitting machine, knitting mantles into the form with which we are familiar now, but the fluid in which they were saturated, was the same fluid that Dr. Welsbach had been making at the first.
- 1 Sep - short biography, births, deaths and events on date of Auer, Freiherr von Welsbach's birth.