It is interesting to compare the crude machine design proposed by Delany in 1885 with the modern arrangements.
The following references illustrate the trend.
Delany (U.S. Patent 316,754, P.B. Delany)
Fulton (Br. Patent 318,119; U.S. Patent 1,759,303, Otho Fulton)
Alexanderson (U.S. Patent 1,792,264, E.F.W. Alexanderson)
Ranger (U.S. Patent 1,803,133; U.S. Patent 1,819,197; I.R.E. Proc., Vol. 17, No. 9, pp. 1564-1575, September, 1929, R.H. Ranger)
Hough (U.S. Patent 1,886,189, C.W. Hough)
Philpott (U.S. Patent 1,985,057, L.R. Philpott)
Young (RCA Review, April, 1938, C.J. Young)
Electronics (Electronics, Vol. 7, pp. 336-340, November, 1934)
(C) Marius Rensen