ix 



of which he was a foreign member, conferred upon him the Copley 

 Medal in 1850. In 1842, and again in 1860, he received the Medal of 

 the Eojal Astronomical Society. 



A great number of his contemporaries in astronomy and mathematics 

 enjoyed the privilege of his acquaintance and instruction. His pupils 

 retained a grateful sense of the amiability and patience with which he 

 laboured to make them worthy disciples of his science. 



Hansen had many offers of other honourable and advantageous ap- 

 pointments ; amongst others one at Dorpat as successor to Struve in 

 1839, one as successor to Bessel in Konigsberg in 1847, one at Copen- 

 hagen ; and in the year 1866 he was offered that of Astronomer to the 

 Berlin Academy. 



In the year 1828 he married the eldest daughter of the Oberforst- 

 meister Braun. He retained his vigour of body and mind to a con- 

 siderable age, and his facility of writing never left him. At times he 

 almost lived at his writing-table, not seeming to feel the need of recre- 

 ation either of body or mind. Healthy sleep was sufficient for the 

 restoration of his powers. , He did not take bodily exercise ; and in his 

 latter years was seldom willing to make any excursion or journey. He 

 twice visited England, mainly to promote the publication of his Lunar 

 Tables ; and he deeply gratified the Director of the Chief Eussian Obser- 

 vatory, Pulkova, by his presence at the 25th anniversary of the founding 

 of that great institution. 



His last years were saddened by a disease of the eyes which altogether 

 prevented him from reading, and even rendered writing very difficult. 

 In the last months of his life he had the additional suffering of a liver com- 

 plaint. His death took place on the 28th of March, 1874. He had in 

 the beginning of that month completed the manuscript paper " On the 

 Determination of errors in the Division of a Hectilinear Scale," and sent 

 it to the printer. The post mortem examination of the head showed a 

 finely formed brain with a remarkably thin skull. 



The main feature of his character w^as an ardent love of truth ; what 

 lie had once recognized as true he maintained with all the energy of con- 

 viction, caring little whether others were convinced or not; and he 

 .sometimes found it difficult to understand how an opinion contrary to 

 his own could be honestly held. Thus he sometimes considered himself 

 aggrieved when he was opposed in things which he had made his own by 

 conscientious study. But when convinced of the excellence of another 

 view, he would at once give his unqualified adhesion to it. 



As Hansen had not studied either at a Gymnasium or a University, 

 and had thus been compelled to forego the systematic training of any 

 high school, he owed all the many-sided learning which he acquired 

 to his own untiring diligence and thirst for knowledge. He im- 

 proved his acquaintance with the French and Latin languages which 

 he had begun at school, as his French and Latin papers sufficiently 

 show. He had also a fair knowledge of English, and even made some 



VOL. xxT. h 



