D O C . 2 9 3 O N C E N T E N A R Y O F K E L V I N 4 6 1 Published in Die Naturwissenschaften 12 (1924): 601–602 on 25 July 1924. [1]William Thomson (1824–1907) was Professor of Physics at the University of Glasgow. [2]See Thomson 1867. Einstein discussed Thomson’s multiplier and its relation to his own Maschinchen in his Lecture Notes for Course on Electricity and Magnetism, University of Zurich, Winter Semester 1910/1911 (Vol. 3, Doc. 11, [p. 28]). [3]See Thomson 1872. The quantity h in the figure above is the capillary depression measured from the surface of the fluid. [4]The constant σ is more commonly known as the surface tension. [5]See Helmholtz 1858 and Thomson 1869. [6]The last equality follows from Stokes’s theorem and the fact that the curl of a gradient is identi- cally zero.