l v i I N T R O D U C T I O N T O V O L U M E 1 6 They first met in Leyden in February 1911 when Einstein gave a talk there and stayed in the Lorentz home (see Vol. 3, Doc. 19 for his notes). Many meetings fol- lowed, not only in Leyden, where Einstein became special professor in 1920, but also in Brussels at the Solvay Conferences in Physics of 1911, 1913, 1925, and, most recently, 1927—all of which Lorentz chaired (see sec. I). They also met and collaborated in Paris and Geneva at sessions of the International Committee on In- tellectual Cooperation of the League of Nations (see sec. II). On numerous occasions Einstein expressed his admiration of Lorentz in strong terms. He famously called Lorentz a “living work of art” (see Einstein to Heinrich Zangger, 15 November 1911 [Vol. 5, Doc. 305]), and in a brief speech at Lorentz’s funeral he used the same simile (Doc. 147). As late as 1953 he wrote, “On the per- sonal level he was more for me than all others I met on the path of life” (see Einstein 1953a). Lorentz’s death had a significant impact on Einstein. He hurried to Leyden to at- tend the funeral, and from there wrote to Elsa about suffering from insomnia. They would both need a holiday in the Engadine, he suggested (Doc. 146). After the fu- neral he paid tribute to Lorentz in a eulogy at Leyden University, where he called Lorentz “both the noblest and most powerful personality and the greatest and stron- gest human being that I have known” (see Appendix G). Shortly thereafter, in early March, Einstein and Elsa arrived in Zuoz for a month’s vacation. But a week later, Einstein was called away to testify before the Supreme Court in Leipzig as an expert witness in a patent dispute. Sources other than Einstein raise valid questions as to the necessity of this trip. According to Elsa, Einstein returned to Switzerland from Leipzig by train “in his own style,” that is, sans sleeping car. Moreover, rather ironically, given its dire and long-lasting con- sequences, the strenuous expedition had actually been “in vain” (Abs. 453), pre- sumably because the case was settled out of court. The memoir of János Plesch, one of Einstein’s physicians, picks up the story: When Einstein returned to Zuoz, “he arrived rather late in the evening when he was not expected and he had to toil up to the house on his own carrying a heavy suitcase. It was quite a hard climb at the best of times and now it was made much more difficult by slippery snow.” Plesch fur- ther observes that Einstein “never took any exercise beyond a short walk when he felt like it (which wasn’t often).” The only other physical exercise was “the rowing home of a heavy yacht in the evening calm when there wasn’t a breath of air to stretch the sails.” Plesch therefore concludes that “the Zuoz incident was […] perhaps the last of quite a series of over-exertions.”[35] Despite Einstein’s 17 March description of his health as “rather shabby” (Doc. 155), he still gave the inaugural lecture at the festive opening of the Davoser Hochschulkurse the very next day. Four days later, he informed his close confidant