The Faust Book, based on the Wolfenb├╝ttel Manuscript:

Historia and Tale of Doctor Johannes Faustus. Ch. XII

Doctor Faustus, being no longer able to obtain answers from his spirit concerning godly matters, now had to rest content and desist from this purpose. It was in those days that he set about making almanacs and became a good astronomus and astrologus. He gained so much learning and experience from the spirit concerning horoscopes that all which he did contrive and write won the highest praise among all the mathematici of that day (as is, after all, common knowledge by now). His horoscopes, which he sent to great lords and princes, always were correct, for he contrived them according to the advice of his spirit as to what would come to pass in the future, all such matters falling duly out even as he had presaged them.

His tables and almanacs were praised above others because he set down naught in them but what did indeed come to pass. When he forecast fogs, wind, snow, precipitation, etc., these things were all quite certain. His almanacs were not as those of some unskilled astrologi who know of course that it gets cold in the winter, and hence forecast freezes, or that it will be hot in the summer, and predict thunderstorms. Doctor Faustus always calculated his tables in the manner described above, setting what should come to pass, specifying the day and the hour and especially warning the particular districts–this one with famine, that one with war, another with pestilence, and so forth.

Historia and Tale of Doctor Johannes Faustus. Ch. XII. The Faust Book, based on the Wolfenb├╝ttel Manuscript