Geitel, F. K. Hans

(b. Brunswick, Germany, 16 July 1855; d. Wolfenbüttel, Germany, 15 August 1923)

experimental physics.

Geitel studied from 1875 to 1877 at Heidelberg and from 1877 until 1879 at Berlin, where he took the examination for secondary-school teaching. From 1880 to 1920 he taught mathematics and physics in Wolfenbüttel. He published almost all his works in collaboration with Elster. Following the latter’s death in 1920, Geitel published a paper on the photoelectric effect in very thin films of potassium, a topic which, like his earlier individual efforts, had been of interest to both (1922). Geitel wrote several comprehensive reports on atmospheric electricity, radioactivity, and photoelectric methods of measurement. Of particular note is “Die Radioaktivität der Erde und der Atmosphäre,” in Handbuch der Radiologie.

In 1899 Geitel received a Ph.D. honoris causa from the University of Göttingen and in 1915 a doctorate in engineering honoris causa from the University of Brunswick. Following his retirement he became honorary professor at Brunswick. In 1910 Geitel represented Germany’s physicists (and Otto Hahn its chemists) on the International Radium Standard Commission in Paris.

See also Elster article in Vol. 4.

BIBLIOGRAPHY

Geitel’s writings include Über die Anwendung der Lehre von den Gasionen auf die Erscheinungen der atmosphärischen Elektrizität (Brunswick, 1901); Bestätigung der Atomlehre durch die Radioaktivität (Brunswick, 1913); “Die Radioaktivitât der Erde und der Atmosphäre,” in Handbuch der Radiologie, I (Leipzig, 1920), 399–457; “Photoelektrische Messmethoden,” in Handbuch der biologischenMethoden (Berling-Vienna, 1921), pp. 1–38; and “Die Proportionalität von Photostrom und Beleuchtung an sehr dönnen Kaliumschichten,” in Annalen der Physik, 67 (1922), 420–427.

There is an obituary notice by R. Pohl, in Naturwissenschaften, 12 (1924), 685–688.

Walther Gerlach