Over the course of the 1920s, they wrote many reports on the Jews, and traveled to the British Mandate of Palestine (now Israel) to research the subject and speak with Jewish leaders such as Chaim Weizmann and David Ben-Gurion.
在整个1920年代，他们写了许多关于犹太人的报告，并且到今天的以色列国（当时的英属巴勒斯坦委任统治地旅行，研究犹太人，并与犹太人领袖哈伊姆·魏茨曼和大卫·本-古理安交谈。