The natural world, although intimately associated with the spiritual world and hardly distinguished from it in the Enoch literature, receives considerable attention, and much of the discussion in both the Ethiopic and Slavonic versions is of a scientific rather than ethical or apocalyptic character. One section of the Ethiopic version is described by Charles[1539] as the _Book of Celestial Physics_ and upholds a calendar based upon the lunar year. The Slavonic version, on the other hand, while mentioning the lunar year of 354 days and the solar year of 365 and ¼ days, seems to prefer the latter, since the years of Enoch’s life are given as 365, and he writes 366 books concerning what he has seen in his visions and voyages.[1540] The _Book of Enoch_ supposes a plurality of heavens.[1541] In the Slavonic version Enoch is taken through the seven heavens, or ten heavens in one manuscript, with the signs of the zodiac in the eighth and ninth. An account is also given of the creation, and the waters above the firmament, which were to give the early Christian apologists and medieval clerical scientists so much difficulty, are described as follows: “And thus I made firm the waters, that is, the depths, and I surrounded the waters with light, and I created seven circles, and I fashioned them like crystal, moist and dry, that is to say, like glass and ice, and as for the waters and also the other elements I showed each of them their paths, (viz.) to the seven stars, each of them in their heaven, how they should go.”[1542] The order of the seven planets in their circles is given as follows: in the first and highest circle the star Kruno, then Aphrodite or Venus, Ares (Mars), the sun, Zeus (Jupiter), Hermes (Mercury), and the moon.[1543] God also tells Enoch that the duration of the world will be for a week of years, that is, seven thousand, after which “let there be at the beginning of the eighth thousand a time when there is no computation and no end; neither years nor months nor weeks nor days nor hours.”[1544] [Sidenote: Mountains and metals.]