V 



Peter Ai^dreas Hansen, born at Tondern in Schleswig, on the 8th 

 of December, 1795, was the son o£ Nikolai Hansen, a prosperous gold- 

 and silversmith of that town. Young Hansen attended the town school, 

 where he learnt the elements of Latin and French, and showed special 

 aptitude for mathematics and phjsics. 



After his confirmation he chose watch-making for his calling, and 

 went to Plensburg to serve his apprenticeship in that business. He soon 

 distinguished himself by his skill and ingenuity in mechanical con- 

 struction, and then set to work on his own account at mathematical 

 studies. His circumstances, and also his father's wishes, were opposed 

 to his ardent desire to study at a University ; and he therefore at the 

 end of his apprenticeship returned home to his parents, and in the 

 year 1818 began his wanderings. He first passed some months in 

 Berlin, where he found some occupation under a master who was one 

 of a Trench colony settled there, and in whose family he acquired some 

 familiarity with the Prench language. 



At the end of the year 1819 he returned to Tondern, and settled 

 down in his father's house as a watchmaker. But as early as the spring 

 of 1820 the influence of a physician, Dr. Dirks, who was interested in 

 matters appertaining to mathematics and physics, and who recognized 

 Hansen's talents, gave a decided turn to his course of life. Dirks suc- 

 ceeded in gaining the consent of the father for the young man to go to 

 Altona to join Professor Schumacher, who was there entrusted with the 

 management of the Danish measurement of an arc of a meridian. 

 Schumacher received Hansen very kindly, and exerted himself to obtain 

 for him an appointment in the measurement. He was, however, in 

 the first instance unsuccessful ; and Hansen, who had meanwhile begun to 

 work at Astronomy in the E^ound Tower, then the Copenhagen Ob- 

 servatory, was thinking of going to Grottingen to study under Grauss. 

 Finding that Grauss was prevented by the measuring of an arc of the 

 meridian in Hanover from lecturing, he was at last induced by Schuma- 

 cher, and with the royal consent, to go at his own expense to Altona (in 

 1820) to take part in the measurement in Holstein. 



After the completion of this task he returned to Tondern, from which 

 place he was recalled to Copenhagen by Schumacher in January 1821. 

 He was employed regularly on the survey. 



Before long, through the influence of Schumacher, the king became 

 interested in Hansen, and from that time forth the latter received many 

 personal proofs of appreciation and recognition of his services, of which 

 he always cherished a grateful recollection. 



In the summer of 1822 Schumacher sent Hansen to Heligoland to 

 assist in some astronomical observations for the determination of geo- 

 graphical positions in conjunction with some English savants. 



Schumacliei' became more and more intimate with Hansen, and a 

 friendship grew up between them which was only to be dissolved by death. 



