This manuscript contains three works by ancient Greek authors relating to astronomy and mathematics. The first (folios 2−33) is the famous poem “Phainomena”(Phenomena) by Aratus of Soli (310–245 ВС) describing the sky and the stars. Written in hexameters, this work combines astronomical knowledge, ancient mythology, and Stoic philosophy. The text is accompanied by marginal notes. During the Middle Ages this work by Aratus was used as a manual. Folio 66 verso contains separate inscriptions of a didactic nature that apparently were made later, written in another hand, and which have no relation to astronomical and mathematical themes of the collection. The second work (folios 34−66) consists of writings by the ancient Greek astronomer Cleomedes (first−second centuries AD). The beginning of the text by Cleomedes is missing from the manuscript. The third work (folios 67−102) is Pythagorikou arithmētikēn eisagōgē (Introduction to arithmetic) by the Neo-Pythagorean mathematician Nicomachus of Gerasa (circa 100 AD). This work is known as the first treatise in which mathematical concepts were given numerical rather than geometrical interpretation. The handwritten pagination contains errors at the start of the work by Nichomachus (folios 68–71); however, there is no interruption in the text. The manuscript is written in ancient Greek, on paper, in the same handwriting (except for folio 66 verso), and without book decorations but with drawings, schemes, and tables. The binding is cardboard, with leather spine and corners, and dates from the beginning of the 19th century. Some leaves have been damaged by book pests. An inscription at the top of folio 2 reads tou Vatoupediou, meaning "from the collection of Vatopedi Monastery.” The manuscript was acquired by the Central Scientific Library with the collection of Greek manuscripts described by Ballin de Ballu as early as 1807. It has a stamp "У.Х.", i.e. University of Kharkov. An inscription in the lower margin of folio 2 was painstakingly struck out and is now unreadable. The well-known authority on Greek manuscripts B.L. Fonkich has suggested that the obliterated inscription “Arsenii" could belong to Arsenii Suchanov (1600−68), who in 1653–55 made a trip to Mount Athos, Greece, where he obtained some 500 Greek manuscripts and printed books. This trip was organized on the initiative of Patriarch Nikon of Moscow (1605−81), a well-known church reformer in Russia who wanted to use the acquired books and manuscripts for the purpose of improving Russian prayer books.