174 WOMAN IN SCIENCE 



doned, because it was then recognized that the conjunction 

 of the superior planets was not something fortuitous, but 

 something that was reproduced at fixed periods by the 

 known movements of these bodies. Writers on the subject 

 made it a point to warn the public that they had nothing 

 in common with astrologers. Among these was Christopher 

 Thurm, who published a work on the conjunction of Jupi- 

 ter and Saturn in 1681. Similarly, the book of Maria Kirch 

 contains only astronomical calculations and nothing more 

 a fact that redounds to the honor of the author and to the 

 age in which she lived. 



The daughters of Maria Kirch, even long after their 

 mother's death, continued to occupy themselves with as- 

 tronomy. They calculated for the Berlin Academy of Sci- 

 ences its Almanac and Ephemeris, which were among the 

 sources of revenue of this learned body. 



During the same period a number of French and Italian 

 astronomers had female collaborators in their own families. 

 Celsus, the celebrated professor of Upsala, and a pupil of 

 the son of Gottfried Kirch, had been accorded a most cor- 

 dial reception, while passing through Paris on his way to 

 Bologna, by De L 'Isle who had a sister who was devoted to 

 astronomy. On his arrival in Italy he found that his new 

 master, the director of the observatory at Bologna, had two 

 sisters, Teresa and Maddalena, both of great learning, who, 

 like their brother, were engaged in the study of the heavens 

 and collaborated with him in the preparation of the Ephem- 

 eris of Bologna. This caused Celsus, in a letter to Kirch, to 

 declare "I begin to believe that it is the destiny of all the 

 astronomers whom I have had the honor of becoming ac- 

 quainted with during my journey to have learned sisters. 

 I have also a sister, although not a very learned one. To 

 preserve the harmony, we must make an astronomer of 

 her." 1 



i ' ' Celebre inter observatores hujus sevi nomen adeptus est God- 

 fredus Kirehius, astronomus nuper regius in Societate Scienciarum 



