D O C . 2 7 0 J A N U A R Y 1 9 2 0 2 2 3 gitimately attracted most avid interest among physicists everywhere and have re- mained unrefuted until today.[2] I cannot but remark, though, that in the current stage of physics I consider it very unlikely that, ultimately, Mr. Ehrenhaft will be in the right with his assertions related to the nonexistence of elementary quanta as required by atomism. Nor do I believe that the findings about radiative forces acting on the tiny particles are fundamental in character, even though no explanation ex- ists at all for these strange findings.[3] Indeed, I cannot refrain from saying that, in his overall assessment of the facts, Mr. Ehrenhaft occasionally lacked the desired objectivity in weighing the experimental and theoretical arguments, which is not in the least surprising for such a temperamental and enterprising personality. The force of his intellectual vitality naturally draws most of the younger researchers in his proximity—even very talented ones among them, like young Smekal[4] —under the spell of his conceptions. No matter how the decision may fall, there is no doubt that Mr. Ehrenhaft has been the source of valuable inspiration and fruitful creativity. I also believe that, with Ehrenhaft’s appointment, any danger of a somewhat one-sided development at the University of Vienna need not be feared, since there will be enough compe- tent and independent minds besides him at that large university. I am convinced that, among the Austrian experimental physicists who may come under consideration, Mr. Ehrenhaft has the most merit. Among the relevant Ger- man colleagues, there is one whose achievements I definitely do value more highly, namely, Mr. J. Franck, who devised a precision research method of greatest signif- icance based on the phenomenon of electron collision.[5] I mention this only in re- spect to a passage in our colleague Lampa’s telegram, which obliges me to make this statement.[6] I may surely leave the question open whether any other suitable experimental physicists within the German-speaking region deserve notice. In or- der to answer such a question conscientiously, I would first have to look about very carefully, for which there is perhaps no cause. In pointing out that I am very willing to answer more questions to the best of my ability, I am, with utmost respect. 270. To Anton Lampa Berlin, 21 January 1920 Dear Mr. Lampa, I am sending you herewith a copy of the letter addressed to Mr. Wegscheider.[1] You are facing a pretty difficult problem there. Perhaps you are not quite satisfied