Updated 06-I-2019

Philip H. Diehl

This article was written by fellow lamp engineer and collector Edward J. Covington, and originally appeared on his own website of biographical sketches of persons involved in the lamp industry. Following his passing in February 2017, and with kind permission of his family, Ed's words have been preserved here in the hope of maintaining access to his writings for the benefit of subsequent generations.

Philip H. Diehl1

Thomas Carlyle is said to have written: "The history of the world is the biography of great men." Upon reflection one must conclude that there is much truth in that statement. This brief write-up concerns one man who contributed significantly to technical developments in different areas as well as in one specific area in which he was at least one hundred years before the time the world would pursue that invention.

Philip H. Diehl (29 Jan 1847 - 7 Apr 1913) was born in Dalsheim, Germany. At the age of 21, in July 1868, he emigrated to New York City where he worked in several machine shops. Then, in that same year, he found employment with the Singer Manufacturing Company in New York City. In 1870 or 1871 he went to work at the Remington Machine Company in Chicago and stayed there until 1875. In 1871 the great Chicago fire occurred and it is said that Diehl had a narrow escape from death; he lost all his belongings to the fire. In 1875 Diehl took charge of experimental work in the improvement of sewing machines in the Singer plant in Elizabeth, New Jersey. This was not a trivial job because by 1897 Singer was manufacturing nearly one million machines a year, including 53 different constructions and 360 varieties of machines. These included the ordinary machine for family use and various types for manufacturing, including machines with 12 needles operated by steam or electricity.

Diehl is famous for having invented one of the very few incandescent lamps of the 1880s which successfully circumvented the Edison patents, and could therefore legally be manufactured. However its construction and resulting cost was so expensive that it did not ever enter production - so in a way Edison's patent was still successful in blocking his competitors. The Diehl lamp managed to avoid infringement by eliminating the glass-to-metal seals that are normally required to bring an electric current from the outside world into the evacuated glass bulb, to light a carbon filament. Diehl instead made an induction coil of copper wire that was directly connected to the filament and entirely enclosed within the evacuated bulb without need for any electrical feedthroughs - it was powered by magnetic induction from a similar coil located outside the bulb. The images below show a photograph of a Diehl lamp, from the William J. Hammer Collection housed at the Henry Ford museum in Dearborn MI, USA, and the front pages of US Patent 276,571.

Diehl Lamp nr. 1885-523 in the William J. Hammer Collection

On the fiftieth anniversary of the development of the incandescent lamp by Thomas Edison, a celebration was held in Dearborn, Michigan at the new Henry Ford Museum. About that same time an article appeared in the Elizabeth, New Jersey newspaper about work that had been performed by Philip Diehl. The content of that article5 is printed verbatim below:

Elizabethan's Invention Used by Westinghouse To Force Royalty Concessions
Other Noteworthy Devices

"Although the entire world is paying honor this month to Thomas Alva Edison on the fiftieth anniversary of his invention of the incandescent lamp, little is known of the importance of an incandescent light which was invented here in 1882 by the late Philip Diehl, Elizabeth manufacturer and founder of the Diehl Manufacturing Company, who was born two months previous to the noted New Jersey wizard and whose life closely parallels that of the "Wizard of Menlo Park." Despite the fact that Diehl's lamp was never produced commercially, it was the axis on which victory turned in a bitter battle against monopoly in the electric industry late in the nineteenth century.

"The Edison celebration has revealed that the models of Diehl's lamp, which was known as an "induction incandescent lamp," along with other original models of his inventions, are being sought by Henry Ford for his collection of Americana at Greenfield, Mich., and by the Smithsonian Institute in Washington, D.C.

"Several models of Diehl's lamp and the originals of his dental motor, the first ever produced; his electric sewing machine motor, which was also the first invented; an alternating current motor and a rotary interrupter, which was the first known device designed for transforming direct electric current into alternating current, have been collected by officials of the Diehl Company here, together with patents and historic data, which will be inspected within a few days by C. L. Bishop, Henry Ford's representative.

Evades Edison's Patent
"The electric bulb, invented by the Elizabeth man, who came here as a machinist for the Singer Manufacturing Company and founded the Diehl Company to produce his most notable inventions, which were applied to the sewing machines turned out by the Singer Company, was the result of a clever idea that evaded the iron-clad patents that Edison held. When Edison, fifty years ago announced the successful culmination of his experiments, practically all the hundreds of inventors who had been working on the problem of incandescent lighting threw up their hands in resignation, for Edison's lamp was protected by patents that covered the "lead-in" wires, which carried the current from the generator to the filament within the glass bulb. The newly-formed Edison Lamp Works acquired the patents and immediately started manufacture, attempting to freeze out all other electric companies who sought rights of manufacture.

"But despite the sweeping victory scored by Edison, Philip Diehl, in the basement of his home, which was then located on Orchard street, between Chilton street and Magie avenue, being one of the four houses on the street, continued his experiments in an effort to avoid infringement on the Edison patent.

"On March 28, 1882, he obtained the first patent on his induction incandescent lamp, which used no 'lead-in' wires. Diehl's accomplishment had been gained by placing a secondary coil within the glass bulb, connected with the filament. The base of this lamp, which was cylindrical in shape, tapering down from the rounded body of the lamp, fitted into a socket which carried a primary coil, to which the current wires were attached. The electric current was forced through the glass casing from the primary coil to the secondary coil and thereby evaded the provisions of Edison's bulb. Two additional patents were granted the Elizabeth man on February 13, 1883, and May 1, 1883.

Invention Hits Edison Monopoly
"Seeing the Diehl lamp as a powerful wedge whereby they could force the Edison patent holders to considerably reduce the excessive royalties they were charging manufacturers who braved bankruptcy by undertaking the production of the electric lamp, the Westinghouse Company bought Mr. Diehl's rights to his invention for a reported ,000, a large sum in those days. Although Diehl's lamp could not have been manufactured and marketed at a price to compete with the Edison lamp, the Westinghouse Company so played their trump, in the form of the Diehl bulb, that the holders of the Edison patent were forced to charge a more reasonable rate for the use of the patent rights. None of Diehl's bulbs were ever produced in quantity although he himself made numerous improvements on his lamp and constructed what is believed to be the first electric table lamp. He likewise made a combination gas and electric bulb fixture, which is included in the collection which the Diehl Company has assembled.

"Diehl's spare time was given to his electrical experiments, most of which were carried out in his home in Orchard street, but the problems that fascinated him were the improvements on the Singer machines on which he was working.

"Philip Diehl was born in Dahlsheim, Hesse-Darmstadt, Germany, January 20, 1847, where he received his education. Apparently his time in school was well spent, but his interest in things mechanical overshadowed his interest in scholastic studies and when 21 years old he came to New York, where he obtained a position with the Singer Manufacturing Company as an apprentice. After working there two years he was transferred by the company to their Chicago plant and while there passed through the horrors of the Chicago fire in 1871. Shortly after that he came to Elizabeth for the company, where he remained until he died in April, 1913, and where he carried on most of his experiments that brought about the founding of the Diehl Company.

"He had been married in Chicago, and he and his wife went to live on the country lane that is now Orchard street. Later they moved to 508 Morris avenue, and still later in the house at 528 Morris avenue (in which his)? daughter, Mrs. Max H. Keppler, now lives with her husband and family.

Displayed Arc Lamp
"Although the greater number of Mr. Diehl's experiments were carried on quietly, one or two of his endeavors into the field of electricity received city-wide attention, and even brought visitors in from the surrounding country. In front of the Corey Building, which still stands at 109 Broad street, Mr. Diehl erected years ago an arc light, which was said to be the first ever erected and burnt in this city.

"The power for the current was derived from the steam plant of the Henry Cook print shop, which was then located in the Corey Building. The steam plant supplied the energy for one of the Diehl dynamos and one night, the exact date of which has eluded enquiry, before a great crowd assembled in the street, Mr. Diehl turned on the light. The arc light was illuminated on several succeeding nights but was after dismantled.

"And although the Diehl incandescent lamp was never publicly acclaimed, despite the power it gave the Westinghouse Company even unlighted, the Diehl plant here stands as a monument, a very industrious monument to a German mechanic who had the "stick-to-itiveness" that enabled him to beat the incandescent monopoly and thereby garner for himself the money that enabled him to carry on his other experiments and found his fortune."

A photograph of some of Diehl's inventions accompanied the Elizabeth article. The caption under the picture read:
"At the left is first dental motor, produced by Elizabeth inventor August 8, 1885. Centered in rear is first alternating current generator built by Diehl for incandescent lamp experiments. This is a development of odd-looking device at the extreme right which was known as a 'rotary interrupter,' one of the first known means of deriving alternating electrical current from direct current. The device in left front center is the first electrical sewing machine motor ever produced. The other four objects are coils, armatures and parts of a generator which Diehl had improved."
Quoting from a biographical sketch of 19233:
"In 1884 Mr. Diehl exhibited at the Franklin Institute, at Philadelphia, Pennsylvania, a dynamo, modeled after the style of his smaller motor, which generated a current for arc lamps, sewing machine motors and incandescent lamps, all covered by his patents. This was adjudged by the judicial committee of the exhibition to be one of the best dynamos exhibited."

"In the late eighties the first Diehl ceiling fan made its appearance, the first electrical ceiling fan with a suspended motor, carrying its own separate set of blades. This early fan evoked much favorable comment among the leading papers and electrical journals, and immediately found its niche among the utilities of the day, the electric fan being in use all over the world, even in Pullman cars and ocean liners. Mr. Diehl also invented an individual motor of the external ring or 'Siemen's type,' which was made part of the balance wheel of the Singer machine, filling a long-felt public need and was welcomed as a great labor-saving device for the home and factory. In 1889 Mr. Diehl received from the American Institute of New York a bronze medal, which bears the inscription, 'The Medal of Merit, awarded to Philip Diehl for Electric Fans and Dynamos, 1889.' "

Genealogy of the Diehl Family
A brief look is taken of the Diehl family, both before as well as after the life of Philip. Limited data are presented on the paternal grandparents, parents and offspring of Philip. In this writing the paternal grandparents will be noted as Generation 1. Available data indicate the following:
Generation 1: Grandfather, Jacob Diehl; Grandmother, Maria Barbara Scherner
Generation 2: Father, Johannes Diehl (b. 22 Aug 1806); Mother, Elisabetha M├Âllinger; married 19 Aug 1840
Generation 3: Philip(p) Diehl (b. 30 Jan 1847); Emilie Loos (b. 28 Jul 1850, or, 21 Aug 1850, or, 1851); married 1873
Generation 4: Daughter, Clara Elvira (b. 2 Apr 1876); Son-in-law, Max Herman Keppler (b 14 Mar 1875); married 5 Apr 1904

The Lamp Situation in the 1880s and Early 1890s
Although the inventive and business life of Diehl is of great interest by itself, it is a separate story from what is of greater interest here. The story of interest here deals with an induction incandescent lamp that Diehl obtained a patent on in 1882. A greater appreciation of this invention is obtained if we leave the story of Diehl for a moment to mention the incandescent lamp situation in the early 1880s.

Edison applied for, and was granted, patents that so thoroughly covered the design of the incandescent lamp that it was very difficult for other manufacturers to come up with a cost-effective design that would not infringe his patents. Several manufacturers did produce lamps that ultimately were found to infringe and injunctions were granted against their manufacture. Diehl's induction incandescent would not have infringed Edison's design had it been manufactured because it did not contain lead-in wires. The idea of an induction discharge lamp appeared again more than 100 years after Diehl's work - for instance the Philips QL, GE Genura and OsramSylvania Endura/Icetron lamps.

Diehl Lamps Housed at the Ford Museum in Dearborn, Michigan
The William J. Hammer Historical Collection of Incandescent Lamps is in storage at the Ford Museum. The inventory sheets show that twelve Diehl lamps are in the collection. The descriptions originally supplied by Hammer, along with their identifications (year and number), are given below.
1885-423 - Diehl (American). Induction arc lamp. The secondary of an individual lamp transformer to the two arc electrodes inside the bulb, which is inserted in the primary coil.
1885-431 - Diehl (American). Diehl induction arc. No. 10 Diehl lamp, carbon electrodes forming arc in vacuum with secondary of coil inside globe and primary used outside to light by induction.
1885-434 - Diehl (American). Diehl induction lamp, one coil is placed inside globe and connected to filament, and other coil wound outside globe, alternating current being employed.
1885-436 - Diehl (American). Early type, double carbon filament No. 2E induction lamp, made by Philip Diehl at Elizabeth, N.J.
1885-439 - Diehl (American). One of Philip Diehl's earliest induction lamps employing secondary inside lamp, bulb connected with carbon filament and with the primary used on outside.
1885-441 - Diehl (American). Early form of Philip Diehl's induction arc lamp. Mr. Diehl's patents for induction arc and incandescent lamps were bought by the Westinghouse Company.
1885-462 - Diehl (American). Induction lamp for alternating current circuits, carbon filament with carbon paste clamps connected to secondary winding inside lamp, the primary coil being in the lamp socket.
1885-466 - Diehl (American). Induction lamp for use with alternating current.
1885-467 - Diehl (American). Induction lamp, carbon filament, with platinum clamps, platinum leads are connected to the secondary winding of an individual lamp transformer, the primary being inside the lamp.
1885-523 - Diehl Induction Lamp (American). Early form of Philip Diehl's induction lamp with straight carbon rod to be made incandescent by electromagnetic induction through the glass. The following image was taken at the storage site at the Henry Ford Museum & Greenfield Village Research Center.
1885-528 - Diehl (American). Induction lamp showing secondary coil inside globe connects to filament.
1885-894 - Diehl (American). Although this lamp was not designed as a regulating lamp, by reason of the employment of an alternating current in its internal and external coils it could be easily regulated.

Genealogy information regarding Philip Diehl was kindly supplied by Frank St├╝ckrath and Stan Stubbe. Loren Haroldson graciously supplied copies of the article in the Elizabeth Daily Journal as well as his article in The Fan Collector. References 1 and 3 were kindly provided by the New Jersey Information Center, The Newark Public Library.

Lighting-Related Patents
  1. US 255,497 - Mar 28 1882 - Incandescent Electric Lamp
  2. US 272,125 - Feb 13 1883 - Electric Incandescent Lamp
  3. US 276,571 - May 01 1883 - Incandescent Electric Lamp
  4. US 314,567 - Mar 31 1885 - Electric Arc Lamp
  5. US 350,482 - Oct 12 1886 - Electric Lighting System

  1. "Philip Diehl", History of Union County, New Jersey, Frederick Ricord, 1897, pp.332-334.
  2. "Obituary Notes", Philip H. Diehl, The New York Times, April 8 1913, p13 col.6.
  3. "Philip Diehl", History of Union County, New Jersey, Vol.2, A. Van Doren Honeyman, 1923, pp.117-118.
  4. "A Life of George Westinghouse", Henry G. Prout, Charles Scribner's Sons, New York, 1922, p.112.
  5. "Diehl's Lamp Hit Edison Monopoly", Elizabeth Daily Journal, Friday Evening, October 25, 1929.
  6. "Lightner, Milton Clarkson", The National Cyclopaedia of American Biography, Vol.J, 1964, p.180.
  7. "Lightner, Milton Clarkson," The National Cyclopaedia of American Biography, Vol.55, 1974, p.25.
  8. "They Always Walked Arm-in-Arm...Philip and Emilie Diehl", Loren Haroldson, The Fan Collector, Apr 2000, pp.13-15.
  9. Diehl Lamp in the collection of Douglas Brackett (archived page).