Dr. Aldar Pacz

Biography
The rich heritage of the development of the incandescent lamp includes a man about whom little is known today. Besides solving a major problem with tungsten wire, which had replaced carbon as a filament, this little-known man also had an effect in other industries that utilized aluminum alloys. His name was Dr. Aladar Pacz. Scientific investigators do not, as a rule, become so famous that their names are household words. Dr. Pacz, because of his apparently introverted nature, was such a person. However, the accomplishments of such persons should be recorded to the best of our ability so that they are not forgotten.

Aladar Pacz was born in Csokas, Hungary on Jan 11 1882 to Dorothea (nee Fuchs) and Samuel Pacz. It is not known where he obtained his early education but it is believed he might have obtained a doctorate in Chemistry in Charlottenburg-Berlin by the age of 23. His last place of residence in Hungary was in Salgotarjan, near the border of Czechoslovakia. He emigrated to the United States from Fiume, Hungary on Jun 11 1905. Pacz sailed on the vessel Ultonia and docked at New York City on Jun 29 1905.

Dr. Pacz arrived in Cleveland on Sep 15 1906. The earliest reference found by this writer that linked him with the General Electric Company is dated 1908, the date of his first known U.S. patent. It is reasonable to assume that Pacz first started with GE at their 45th Street facility (the old Brush Works and later the Euclid Lamp Plant) and perhaps moved into the Nela Park facility in 1914.

Dr. Aladar Pacz was granted 46 U.S. Patents, issued between the years 1908 and 1933. His basic tungsten wire patent is No 1,410,499, applied for Feb 20, 1917 and issued Mar 21, 1922. It is also known that Pacz was granted at least one Austrian, four British, nine Canadian and four German patents (see below).

Aladar Pacz married Bertha Philipps, a young lady from Cleveland, on Jul 23 1907; he also applied for citizenship in the Common Pleas Court in Cuyahoga County on that same date. He was 25 years of age at the time and described himself as a Caucasian of fair complexion, 5 feet 11 inches tall, 153 pounds, with brown hair and blue eyes. His Certificate of Naturalization was dated Nov 12 1912.

He appears to having travelled to Europe periodically. The following information was retrieved from the Archives of the New York Times. On December 27, 1933⁷ Pacz sailed from New York. The ship destinations were the Channel ports, including Bremen and Hamburg. Then, on March 30, 1934⁸ he returned to New York. On January 7, 1935⁹ it was reported that he returned again to New York from the same European ports.

Early Work
Based on a report in the GE files dated Oct 29, 1909, it appears Pacz experimented with a new carbon paste for attaching carbon filaments to lead wires. In 1909 he also worked on molybdenum-tungsten support wires for tungsten filament lamps. Pacz then undertook a task that was to result in the solution of a major problem being encountered with tungsten filament lamps.

The carbon filament ruled king until the first decade of the 20th century; then tantalum and osmium appeared for a short time. Sintered tungsten appeared about 1907. William David Coolidge then developed ductile tungsten, which resulted in a marked improvement in lamp efficacy. In 1912 Irving Langmuir developed a coiled tungsten filament gas-filled lamp. Unfortunately two wire problems prevented the General Electric Company from immediately taking full advantage of that milestone development. One problem was offsetting and the other was sag. When the Coolidge-processed wire recrystallized upon heating, the grains would grow as wide as the wire diameter with boundaries that were essentially perpendicular to the wire axis. The wire structure was often compared to the structure of bamboo. When operated at normal temperatures large sections would slip (offset) relative to each other, similar to slippage at a fault line in the earth. In the parlance of today one would call this sliding at a transverse grain boundary. Such a condition would lead to fracture at room temperature. Sag is simply elongation of the coil due to its own weight in a gravitational field. Sag would result in a drastic lowering of the efficacy of lamps of the Langmuir description.

Coolidge found that offsetting could be prevented when thoria was included as an additive at the powder stage. The result of the presence of thoria in the wire is a small grain size. Such a wire was found to sag terribly. Thus, while thoria prevented offsetting, it resulted in sag. Something different had to be done to eliminate both offsetting and sag.

During Coolidge's work on the development of ductile tungsten it was occasionally found that some wire neither offset nor sagged. Wire lots were not consistent. It was suspected that the oxide batch was picking up some favorable impurities from the crucibles being used. The crucibles were referred to as Battersea or Hessian. The materials used to make them came from certain sections of England. A crude analysis of the clay used in a Hessian crucible showed the following: silica, 64%; alumina, 24%; iron oxide, 2%; lime, 1%; loss on ignition, 7%; and other constituents, 2%.

It was surmised then that additions of silica and alumina to the oxides before reduction might help in the offsetting problem. Traces of silicon and aluminum did lead to large grain structures in the wires. Such large grains were necessary to give a nonsag structure but large grains alone were not enough to solve the problem.

Aladar Pacz undertook many experiments before success was achieved. A non-offsetting and non-sagging tungsten wire was obtained by the addition of potassium to the tungstic oxide. Potassium was different from silicon and aluminum because of its larger atomic size. However, the reason for the interlocking large grain structure developed by Pacz was not obvious then and escaped explanation until the 1960s and 1970s. The main tool for investigation in the 1920s and 1930s was the optical microscope. When photographs from that time period are viewed it is clear that not much besides grain size could be determined. It took the more recent sophisticated scanning electron microscope to detect the arrays of submicroscopic bubbles, which contain potassium, that led to an interlocking grain structure and improved wire strength.

Within the General Electric Company Pacz's non-sag, non-offset wire is referred to as 218 wire. A story is told that the wire resulted after the 218th experiment. However, another explanation is that the title #218 was derived from the serial number of the lot of raw tungstic acid used in the first production of the new material by Pacz. Another version of the naming was conveyed to me verbally by a colleague, Eugene Lemmers; he, himself, had been told the story. That version goes something like the following. Pacz worked at the West End of the second floor in Building 323 at Nela Park. Apparently he had experienced superior wire performance (no offsetting and little sagging) in test lamps on the burning racks. For want of a piece of paper he jotted down, on the inside cover of some book matches, details of the wire additives and processing that led to the improved performance. The book matches were placed either on the bench top or on his desk. Now as it happened, Dr. Pacz was absent from work for several days and when he returned found that the cleaning lady apparently had thrown the matches away. As he did not remember what the details were, he had to set out again to find them. After the 218th experiment he rediscovered the magic set of conditions. Where the truth lies is not known. Regardless, the worldwide manufacturers of tungsten wire agree that Aladar Pacz is given the credit for this development. It is believed this development was completed and named by Jul 1915.

Some Later Work
Aladar Pacz left the General Electric Company sometime in the early 1920s. His home was near Nela Park, as was a business that he established. It was there that he developed aluminum alloys. One of his developments in that area attracted some attention in the local press. As part of the spoils of World War I, the United States was to receive a dirigible, which would be made by the famous Zeppelin Company at Friedrichshafen, Germany. Until that ship was christened in the United States, it was known as ZR-3; after the christening it became the U.S.S. Los Angeles. The delivery date was made possible, in part, because of one of Pacz's silicon-aluminum alloys. After the war, Germany was not in good financial condition, and it could not afford to use copper in its aluminum alloys. Pacz's alloy, therefore, could be used to some extent in needed castings. His alloy was used by the French in streetcars and railways, and the Belgians, British and Germans also used it. In Germany the alloy was used in motor blocks of the expensive Daimler car. That car was later renamed after the 10-year-old daughter of the businessman, Emil Jellinek. Thus, the Mercedes name on an automobile was born.

Aladar Pacz kept contact with personnel at GE's Nela Park, and in particular with Dr. Matthew Luckiesh. Pacz and Luckiesh were interviewed prior to the sailing of the ZR-3 and were asked details of the use of the alloy in the new dirigible. For several days in Oct 1924, the Cleveland newspapers carried stories about the anticipated and actual inaugural flight of the ZR-3 over the Atlantic to its destination in Lakehurst, New Jersey. As helium was available only in Texas, and then only in limited quantities, the flight across the Atlantic was made with hydrogen as the buoyant gas. Once the ZR-3 landed, the hydrogen was replaced with helium. Later in time, the dirigibles U.S.S. Macon and U.S.S. Akron crashed, which left the Los Angeles as the only U.S. Navy dirigible in this country not to come to a violent ending.

The Final Incomplete Chapter
Based on the application date of his last U.S. patent, it is concluded that Aladar Pacz was living in Weehawken, New Jersey in Nov 1933. My story has to end at this point because nothing more is known about this developer of metals. It is hoped that someone will be able to add more information to this biographical sketch. Attempts have been made to gain more information, including a visit to the Weehawken Public Library, but nothing else was found.