Abstract
Babylonian rising time schemes specify positions at or close to culminating stars when the Sun rises or sets for selected dates of a year. In an advanced version, points on the ecliptic rising on the eastern horizon instead of the Sun are given in relation to culminating stars. The attribution of rising times corresponds to the determination of oblique ascensions, that is, the relationship between arcs on the ecliptic and their respective arcs on the celestial equator. All the preserved texts dealing with this topic are descriptive; this means that they recount astronomical facts but do not explain how the recorded data can be used.
In the first chapter, John Steele summarises earlier research and tersely explains the topic. He embeds the rising time texts in the bigger picture of Babylonian astronomy in the first millennium
The second chapter explains concisely the astronomical preliminaries the reader has to know in order to understand the content of the following chapters. The Luni-Solar and the schematic calendar are outlined, the distinction between schematic and other types of Babylonian astronomy is clarified, the meaning of ziqpu stars as stars that culminate at a certain time at night on a specific day of the year is elucidated, and the concepts of the zodiac as well as the micro-zodiacal signs are explained.
In Chapter 3, Steele presents his convincing reconstruction of the calendar-based rising time scheme using three sources whose astronomical meaning hitherto was obscure. He presents transliterations and translations of the texts where they are not duplicates or of a very repetitive nature. A monthly as well as a daily scheme can be traced and both are in agreement with each other: between the winter and the summer solstice, the distances between culminating points at sunset in two successive months are equal to 40 UŠ per month in the monthly scheme and equal to 1;20 UŠ per day in the daily scheme, and between the summer and the winter solstice equal to 20 UŠ per month or 0;40 UŠ per day, respectively.
For a reader who is not well acquainted with Babylonian star names and constellations, it may have been useful to extend Table 3.4 (or Table 2.1) to give also the most common Babylonian writing of their names in the way Steele restores them in his transliteration of the fragments containing the daily scheme.
Chapter 4 deals with a further development of the calendar-based scheme: the zodiac-based rising scheme. Culminating points with reference to ziqpu stars are labelled for the beginning and the end of a zodiacal sign or for the end of each twelfth of a sign, a so-called microzodiac sign. The detailed texts give additional information most of which can best be understood in connection with some astrological meaning. Starting with Aries, the zodiacal signs are assigned in a regular manner to the three watches of the day (morning, noon, and afternoon). Each of these watches is equated with one specific day around the end of the month and with certain stars in the path of Ea, Anu, and Enlil “that flare.” Steele convincingly shows that apart from these additions, the scheme is identical to the earlier calendar-based scheme.
The fifth chapter deals with related Babylonian texts. In the final chapter, Steele suggests that the main purpose of schematic astronomical texts in general was to provide a description of astronomical facts but not to provide a means of astronomical calculation as previously suggested.
Steele’s book appeared in the Springer Briefs in History of Science and Technology series. It is a pity that considering the quality of the printed figures the price of the book is comparatively high. Nonetheless, this book is recommended reading for anyone interested in ancient astronomy and especially in Babylonian astronomy.