Rav Yaakov Weidenfeld Kochav MiYaakov Yekele

His one volume of responsa, entitled Kochav MiYaakov, was a mere fraction of the thousands of responsa that he wrote, but which were lost in the two world wars. Rav Yaakov’s glosses to Seder Taharos and Talmud Yerushalmi were written in one day, as is indicated by their original title, Hagahos Chad Yoma, (5654/1894).