24 leaves, 23 cm. A book by Rabbi Zev Wolf son of Shmuel Gershtel the Rabbi of Yaritshov. Explains the passage of the stars and the heavenly hosts, calculations of Kiddush HaChodesh and more. A map of the stars was enclosed enclosed in a number of copies, it is not in this copy. The errata appears at the end of the book [there are copies without the errata]. Stamps of Rabbi Avraham Moshe Babad Av Beit Din of Gura Humorului. Pleasant Cover, fine condition.