THE PRUSSIAN ACADEMY OF SCIENCE. 173 



the approval of the government censor. Thus the right of free pub- 

 lication, which the academy and its members had long enjoyed, was 

 invaded, and in spite of protestations, freedom of publication was sus- 

 pended for five years, and was not formally removed till July, 1843. 

 But a petition for freedom on the part of the academy to issue its 

 official papers without submitting them to censorship was favorably 

 received by the king, although that privilege was denied to its mem- 

 bers as individuals. 



The physical class of the academy, stimulated by what the historical 

 class had accomplished, set itself about great enterprises. In 1820 it 

 sent Ehrenberg, who had already won fame as a microscopist, to Egypt. 

 He and Hanpricht, his associate, explored the Libyan desert, Lower 

 Egypt, Upper Egypt as far as Nubia, the coast of the Red Sea and 

 passed through Arabia, Petrea and Syria. To the funds required in 

 1823 the king made generous gifts from his private resources. The 

 year 1825 was given to travel and study in Abyssinia. In the 85 boxes 

 sent to Berlin at different times there were geological specimens of 

 great variety, many fossils, a large selection of dried plants, as well as 

 of woods, fruits, seeds, weapons and instruments in use in northern 

 Africa. Of animals there were above 4,000 different specimens in ten 

 times that number of individual examples, and 2,900 specimens of 

 plants. This journey and its outcome were significant for both the 

 academy and the progress of science. 



The scientific section of the academy put forth a special effort in 

 1825 to strengthen its influence by securing men of the first rank for 

 its various departments. As the astronomer had failed to keep abreast 

 of the times, Oltmans and Encke were brought into the academy. 

 Encke served it forty years, and till 1863 was secretary of the mathe- 

 matical class. It was through his influence and discoveries that the 

 academy gave such an impulse to astronomical studies. The new 

 building for astronomical uses, begun in 1832, was completed in 1835, 

 and $375 a year for six years was set aside by the government for its 

 support. A map of the heavens was planned, on which the position 

 of all fixed stars above the ninth and tenth magnitudes was to be shown. 

 The heavens were divided into 24 sections and assigned to as many 

 observers. It was supposed that the map, which was a pioneer of its 

 kind, would be completed in four years. In fact, it was only partially 

 completed in 1859, but it prepared the way for the more accurate and 

 extensive work of later days. Not a little was done by the historical 

 class in archeology, and the need of special funds and accurately trained 

 laborers in this field was seen to be so pressing that in 1829 the Archeo- 

 logical Society of Berlin was formed. Aid was given Graff for a Ger- 

 man dictionary and to Bopp for an edition of the Indian poem, 

 ' Mahabharata. ' 



Hegel's philosophy with its theories of panlogism and its doctrine 



