Crowther (1967) gives the following figures:
In 1937 the Bell Telephone Laboratories, an independent subsidiary of the Bell Telephone Company that employed more than 300,000 persons, had about 4,200 employees, of whom about 2,000 were scientists.
Over the period 1920 - 1937 some 500 of its scientists had contributed to about 1,100 published papers of original research.
Crowther, J. G. (1967) The Social Relations of Science. 2nd ed. The Cresset Press, London.