This is an excellent question.
The best answer and discussion is one provided by the superb article by Ed Owen( General Electric-Schenectady) in the History Section of the IEEE Industry Application Magazine, Vol. 3, No.6, Dec. 1997. The title of the article is "The Origins of 60 HZ as a Power Frequency. Additional information can be found in the following publications-which are all mentioned in the article.
B.G. Lamme, "The Technical Story of the Frequencies." AIEE Trans, vol. 37, 1918.
C.F.Scott, The Engineering Evolution of Electrical Apparatus; I. The Beginnings of the Alternating-Current System," The Electric Journal, vol 11, January 1914,pp 28-37.( My note C.F. Scott was also the one that "invented" the Scott-T transformer connection for phase transformation. I've used this connection to convert a three phase sytem to a two phase 4-wire system.)
B.G. Lamme, "The Engineering Evolution of Electrical Apparatus;XXIX, The Technical Story of the Frequencies," The Electric Journal vol,15, June 1918,pp230-237.
D.B. Rushmore, "Frequency," AIEE Trans., vol. 31, 1912 pp. 955-83. Disc. 974-78.
L.B Stillwell, "Note on Standard Frequency," IEE Journal, vol.28, 1899,pp. 364-66.
E.L. Owen, "Mill Creek #1-A HistoricalMilestone," IEEE Industry Application, vol. 3, May/June 1997,pp.12-20. this is another excellent article.
In summary it appears that the best evidence shows that the birth of 50HZ and 60 HZ was related to methods of solving light flicker associated with arc lighting. Because the type of fixtures were different in Europe and the US, the method of solution was slightly different( fixture construction and wind exposeure). In 1891 Westinghouse Engineers selected 60 HZ as their their new power frequency and that same year AEG engineers in Berlin selected 50 HZ as their standard frequency.
These two frequencies remain the principal power frequencies throughout the world. Interestingly enough in 1893 Steinmetz(just transferred from Eichmeyer to Thomson-Houston Companies) was involved in a problem on the system for Hartford Conn. Steinmetz solved the problem which had baffled many others and showed that the problem was caused by a transmission line series resonance which were excited by the 125 HZ power frequency in use. His proposal was to cut the frequency in half of the initial value or 62.6 HZ. GE installed the Mill Creek system in California at 50 HZ(1893). This is discussed in E.L. Owens article mentioned above. GE found itself lagging behind Westinghouse in the sale of AC equipment and changed to 60 one year after the comissining of Mill Creek.
Hope this helps.
