Nobel prize to R. A. Millikan awarded in 1923 "for his work on the elementary charge of electricity and on the photoelectric effect''
Millikan, R.A.; On the Elementary Electrical Charge and the Avogadro Constant
Phys. Rev. 2 (1913) 109;
Reprinted in Great Experiments in Physics (Henry Holt and Company, New York, 1960) edited by M. H. Shamos.
The Physical Review - the First Hundred Years, AIP Press (1995) 23.
The experiments herewith reported were undertaken with the view of introducing certain improvements into the oil-drop method of determination e and N and thus obtaining a higher accuracy than had before been possible in the evaluation of these most fundamental constants... The results of this work may be summarized in the following table in which the numbers in the error column represent in the case of the first six numbers estimated limits of uncertainty rather than the so-called "probable
errors'' which would be much smaller... itemize Elementary electrical charge e = 4.774 ± 0.009 x 10-10 Number of molecules per gram molecule N = 6.062 ± 0.012 x 1023 Number of gas molecules per c.c. at 0° n = 2.705 ± 0.005 x 1019 Kinetic energy of a molecule at 0° E0 = 5.621 ± 0.010 x 10-4 Constant of molecular energy e = 2.058 ± 0.004 x
10-16 Constant of the entropy equation k = 1.372 ± 0.002 x 10-16 itemize (Extracted from the introductory part of the paper.).
Related references More (earlier) information appears in R. A. Millikan, Phys. Rev. XXXII (1911) 349;
First precise measurement of the charge of the electron and the Avogadro constant.