The cross-staff is an instrument for measuring angles, invented by Gersonides (1288–1344) in the 1330s. The Latin text describing it, written in 1342, refers to it as baculus Jacob. Between the fifteenth and the eighteenth century, this instrument was widely used in astronomy, surveying, and navigation. Scholars have assumed that the early modern cross-staves have all descended from that of Gersonides. Here I will question this assumption: (i) late-fifteenth-century astronomers do not refer the cross-staff with the term baculus Jacob, but their staff may indeed have its origin in Gersonides’ text of 1342; this hypothesis needs to be checked. (ii) In the surveying literature, German artisans and craftsmen describe the cross-staff and refer to it as “Jakobsstab,” but it is likely an independent invention. I also suggest that the “Jacob” after whom the Jacob’s staff is named is not the Patriarch Jacob (as has been assumed), but St. James (= Jacob) the Great, who in the eleventh century became the object of great veneration.
On December 10, 1757 R. David Fränckel (1707–1762), Chief Rabbi of Berlin Jewry, delivered in German a sermon on the occasion of Frederick the Great's victory at Leuthen. Scholarly consensus has ascribed this sermon to Moses Mendelssohn (1729–1796), and it is included in the authoritative edition of Mendelssohn's Complete Works (Jubiläumsausgabe). Drawing on an earlier sermon by Fränckel that has only recently come to light, this paper argues that the "Leuthen Sermon" was in truth authored by Fränckel himself, in Hebrew, and that Mendelssohn only translated it into German. This re-attribution affords a better appreciation of Fränckel's important role in the emergence of the Berlin Haskalah. It is also suggested that Fränckel's thought was closer to Mendelssohn's than hitherto realized, and that Fränckel played a greater role in Mendelssohn's intellectual development than previously thought. The Appendix points out that Fränckel's sermon enjoyed a world-wide success: the German version was reprinted a considerable number of times in Germany; and an English translation was published in London and was reprinted in the New World by both Jews and Christians.
This article presents the history of a printing press that operated at several places near Berlin during the first half of the eighteenth century, culminating in the epoch-making reprinting of Maimonides’ Guide of the Perplexed in 1742. The press was established in Dessau in 1694 by the court Jew Moses Wulff (1661–1729), and was run by several printers, notably the convert Israel b. Abraham (fl. 1715–1752). Using the trajectory of the Wulff press as a case study, I examine the relations between scholars, patrons of learning (especially court Jews), printers, and book publishing. The inquiry will highlight the considerable role that court Jews played in shaping the Jewish bookshelf, notably by choosing which books (reprints and original) would be funded. Surprisingly perhaps, although court Jews were in continuous contact with the environing culture, they did not usually favor the printing of non-traditional Jewish works that would favor a rapprochement.