||The Jewish calendar and its calculations by Selig Slonimski (1810–1904), Hebrew popular science writer and editor. He was born in Bialystok and wrote popular science articles during the Haskalah period. Slonimski coined new Hebrew terminology where necessary. Some of his mathematical and astronomical interpretations of obscure passages in the Mishnah found their way into editions of the Mishnah printed in Zhitomir. Slonimski was also an inventor. Among his inventions was a calculating machine, for which he was awarded a prize by the Russian Academy of Sciences (1844). In 1862, Slonimski founded Ha-Zefirah, a Hebrew newspaper devoted mainly to popular science articles written by himself and a team of collaborators, adherents of the Haskalah. The paper ceased publication after only a few months, upon Slonimski's appointment as inspector of the Government Rabbinical Seminary in Zhitomir and Hebrew censor for South Russia. In 1874, when the Seminary was closed down, he renewed publication of Ha-Zefirah, first in Berlin and, from 1875, in Warsaw. The periodical was edited in the moderate spirit of the Haskalah, avoiding conflicts with the Orthodox by presenting scientific innovations in a manner acceptable to them.
In 1884, Slonimski's disciples and admirers celebrated the 50th anniversary of his literary career, and two collections of his articles appeared under the title Ma'amarei Hokhmah ("Essays of Wisdom," 1891–94). In 1886, when Ha-Zefirah began appearing daily, Nahum Sokolow joined the editorial board and, in effect, took over the editorship, though Slonimski continued to contribute articles. A list of his articles appeared in Ha-Zefirah, 14 no. 91 (1887), 5–6.