Page:Über die Konstitution des Elektrons (1906).djvu/50

of the measurements executed by Starke^[1] with fast cathode rays. Maybe, by application of Wehnelt's gleaming oxid-cathodes, it is possible to obtain sufficiently steady discharges also with even higher voltages than 38000 volt – the upper limit up to which Starke came. Consequently it doesn't appear to be impossible to decide by which factor, ²⁄₅ or ½ or ⅓, one has to multiply the term depending on $\beta ^{2}$, to achieve precise agreement with the observed variability of $\epsilon /\mu _{0}$^[2]. However, also in this case it is about the most attainable precision in measurement and calculation, and consequently about the expenditure of extraordinary means.

1. H. Starke, l. c.
2. See also appendix p. 548ff