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Rh month in error, while even the Prutenic Tables could hardly fix the day correctly, not to speak of minutes or seconds. A calendar should contain the usual information as to the aspects, time of sunrise and sunset, time of rising and setting of the moon and planets, and the names of the principal stars rising and setting at the same time. The moon is of particular importance as it is nearest to the elementary world, but even the planets must influence the weather. Lastly, a calendar should give the probable weather for every day, concluded from the configurations of the celestial bodies. He would warn the reader not to expect too much from the weather predictions, partly because much remains yet to be done in exploring the motions of the stars and their effect, partly on account of the fluidity of the inferior matter, which sometimes delays, sometimes hastens the effect produced by the stars. But any blame should rest on him and not on the art. Besides terrestrial influences must act differently in different parts of the earth, so that one configuration of the stars cannot have the same effect in several localities. Therefore he has undertaken this work principally in order by observation to learn the effect of the stars on this part of the earth, so that our posterity may profit thereby, and in order to secure this object he exhorts all meteorologists to take observations of the weather.

The only part of the diary given in the book is that relating to the total eclipse of the moon on December 8, 1573. It fills twenty-four pages, including two full-page woodcuts—one of the progress of the eclipse, the other of the earth, moon, and planets at that time. He gives first the calculation of the eclipse by the Prutenic Tables, with all