Zabel was a native of Harvard, Illinois and received a degree in electrical engineering from the University of Wisconsin in 1909. He started to work in the Engineering Department of the National Electric Lamp Association as a student engineer in 1909. In January of 1911 he transferred to the Cleveland Wire Division as foreman. Zabel then went to work, in August of 1915, in the Lamp Development Laboratory at Nela Park.

William Zabel investigated various aspects of tungsten wires made by Aladar Pacz, the developer of nonsag tungsten. Results of these studies were reported during the time period of 1915-1919. He was also concerned with the design and manufacture of incandescent filaments, as well as electrodes for fluorescent lamps, as indicated by the following list of his U. S. patents.

------No.-----------------------Description-----------Date--------------Co-Inventor(s)
1,403,727 - Wire Cleaning Method and Apparatus - 1922/01/17 - with L. E. Reakes
1,661,866 - Apparatus for Cutting Wire into Lengths - 1928/03/06
1,752,828 - Method and Apparatus for Mounting Filaments - 1930/04/01
1,834,781 - Method for Treating Filaments - 1931/12/01 - with George E. Inman
1,992,797 - Method of and Apparatus for Treating Filaments - 1935/02/26
1,992,798 - Method of Treating Leading-In Wire - 1935/02/26
2,142,865 - Method of Manufacturing Filaments - 1939/01/03
2,165,105 - Apparatus for Manufacturing Filaments - 1939/07/04 - with Robert F. Krejci
2,179,367 - Method and Apparatus for Treating Filaments - 1939/11/07
2,278,816 - Incandescent Electric Lamp - 1942/04/07
2,371,205 - Coiled Filament or Cathode and Method of Manufacture - 1945/03/13
2,422,457 - Coating Apparatus - 1947/06/17
2,441,863 - Electrode for Discharge Devices - 1948/05/18
2,445,706 - Vapor-Supplying Cartridge - 1948/07/20
2,479,192 - Cathode - 1949/08/16
2,479,193 - Articulated Cathode - 1949/08/16
2,518,970 - Method of Manufacturing Vapor Supplying Cartridges - 1950/08/15
2,545,909 - Apparatus for Applying Emission Material to Cathodes - 1951/03/20
2,664,361 - Method and Apparatus for Applying Electron Emission Material - 1953/12/29

In addition to the above U. S. patents, Zabel was issued 18 Canadian and 2 German patents.

Zabel's single departure from manufacturing problems appears to be a design for a decorative candle incandescent lamp. The first page of that patent (U. S. 2,278,816) is shown below.

The two pictures shown below were kindly supplied by Tim Tromp. The lamp pictured is in his collection. Although it is not certain, it might be that this design never went into production. It is surmised that this lamp was made in a "model shop".

From 1947 to 1952 Zabel was a consulting engineer. He retired in 1952.

William Zabel married Emma C. Schwan on October 22nd 1913 and they had a son, Paul.

Zabel passed away in Fort Myers, Florida after suffering a stroke. He was interred in Lake View Cemetery, Cleveland, Ohio.

Note: The picture of Zabel was scanned from The Book of the Incas¹.

Acknowledgement
The writer thanks Tim Tromp for the use of two of his photographs of an engineering sample of Zabel's decorative candle lamp.

References
1) Book of the Incas, 1930.
2) Obituary, "William P. Zabel", The Plain Dealer, Sep 18, 1977, Section 3, page 17.