Correction

In the article by Dr. Millikan entitled "The Progress of Physics From 1848 to 1948" (Science, September 3, p. 230) the last part of the fifth paragraph should have read: ". . . Ampere, the Frenchman, in the 1820's had developed that field with great skill and insight; while England's unsurpassed experimentalist, Faraday, had in 1831 discovered electromagnetic induction and in 1834 had laid the secure foundation for the whole field of electrolysis."