l i v I N T R O D U C T I O N T O V O L U M E 1 4 (Docs. 94, 99). He was now “very pleased” and believed that, without “foul influ- ences” (i.e., his mother), the boy would be “the ideal son” (Doc. 100). In Septem- ber, he spent a further three weeks with him in Kiel “in most beautiful harmony” (Docs. 108, 111). Hans Albert, an ETH student, diligent and smart, also participat- ed in the work on the gyrocompass, so much so that Anschütz informed Einstein of his intention to leave the Kiel factory to the young man (Docs. 245, 269). Einstein was happy with the offer, and suggested his son spend the 1925 summer vacation in Kiel (see Docs. 348, 371, 372, 383, Abs. 516). The issue of the investment of the prize money remained contentious for a while, and was eventually resolved through the good services of Fritz Haber, who again served as an intermediary, as he had done almost a decade earlier during Einstein and Mileva’s separation. Einstein assigned control of the American investments to Mileva (Docs. 202, 205). He wrote to her that their sons “give my inner life its fin- est feelings” and that he was happy to regard them as a continuation of his own ex- istence. He was prepared to “restore our good relations” (Doc. 235). Mileva, appeased to some extent by the conciliatory letters, nevertheless doubted whether their past could be forgotten. She could not “find joy” with anything, not even with the house, whenever she remembered the previous year’s exchanges (Doc. 267). In late May 1924, after a thorough search of available properties in Zurich, Mi- leva purchased a house at Huttenstrasse 62, close to the ETH and the university, which Einstein, on a visit in late July, considered “a good purchase” (Docs. 265, 299). By late November 1924, Mileva and the sons had moved into the house (Doc. 382). Half a year later, following his return to Europe in late May 1925, Ein- stein wrote that he assumed he would be staying in the new house if he were to visit in the summer. But he also encouraged all three of them to visit Berlin. That would be a sign that “the old hatchet has been buried” (Doc. 489). Einstein also utilized his improved finances to assist his sister. In May 1923, Maja Winteler-Einstein completed the draft of an intended biography of Einstein.[22] With its sales she and her husband, Paul Winteler, hoped to reduce the debt on their house outside Florence. It appears that at first Einstein agreed to the publication of the book (Doc. 26, Abs. 105). But he may have reconsidered, since by late November 1924 he supplied direct financial help to Maja and Paul. In re- turn, he asked that they sign a document promising not to sell or mortgage the house (Docs. 364, 378, 391). In June 1923, Einstein’s older stepdaughter and secretary, Ilse Einstein, who had been suffering from colic, underwent abdominal surgery (Docs. 27, 59). Less than a year later, she married the German-Jewish literary editor Rudolf Kayser. Einstein gave Ilse his American savings as a dowry (Docs. 223, 230). Shortly after the wed- ding, Ilse became unwell again, and there was speculation that she might be suffer- ing from tuberculosis (Docs. 242, 248).