Walter Kaufmann

“ When one specifies in an absolute way, then it is much harder to reach agreement, because an error of 1% in the determination of , already gives an error of 10 or 20% for . Therefore it is necessary, to compare the relative values with each other. For the time being, an absolute measurement was carried out by me only for the first, older experiments of the previous year. There, one gets deviations of up to 7% for the value of . If one calculates (after correction of this deviation) from that the value of , then one gets the value , while was found for cathode rays. ”

“ Curves II and III are recorded with a voltage of 2000 volt, and at curve IV the voltage was increased to ca. 5000 volt by the rotating switch as described l.c. The agreement with theory is so good, as it can be expected by the precision of observation, since the mean error of the individual values only amounts 1 to 1,4% with respect to all four curves. ”

“ I want to ask after the shortcomings of the photographic plate: can we recognize them by the fact, that the errors always occur at the same place and the same magnitude?
Kaufmann: These errors are almost always present, however, they are not systematic, i.e., they do not belong to the curve, since they occur upon the single plates at quite different places and they are different with respect to magnitude and sense.
↑ Verhdl. D. Naturf. u. Ärzte Hamburg 1901. II. 1. 45. Gött. Nachr. 1901. H. 2. ↑ Phil. Mag (5) 44. 340, 1897. ↑ Gött. Nachr. 1902. H. 1. ”