606 FRIEDRICH WILHELM AUGUST ARGELANDER. 



the observatory of Abo, in Finland ; after the great fire there the Uni- 

 versity was removed to Helsingfors, and Argelander, with the instru- 

 ments of the observatory, went too. His work at Abo was chiefly 

 devoted to his famous catalogue of 5G0 stars ; a model catalogue, which 

 is yet unsurpassed for convenience and accuracy. The work was com- 

 pletely reduced, and published at Helsingfors. Tliis same material 

 enabled him to fix, with accuracy, the direction in which the sun is 

 moving, as surmised by Sir William Herschel and others. 



In 1837 he removed to Bonn. The four years succeeding, as he 

 had no observatory, were given to his Uranometria Nova, the first 

 attempt at a delineation of an exact star-map for naked-eye observers ; 

 and a most admirable work it has proved to be. He laid down upon 

 the map about forty stars not previously observed even with the tele- 

 scope. 



In 1841 a temporary shed was fitted up for a transit-instrument and 

 clock. By adding a divided arc to the transit he was able to get ac- 

 curate delineations, as well as right ascensions, of about 2G,000 stars, 

 continuinir Bessel's zones to 80° of north declination. 



When the observatory was finished and provided with instruments, 

 he continued the same zones from 15° to 31° of south declination; it 

 is this work which our colleague. Dr. Gould, is now continuing still 

 farther south. 



After this work was completed, the great survey of the northern 

 heavens, on a still more minute scale, followed. The maps and rough 

 plans of all stars to the magnitude 9.5 north of 2° of south declination 

 came out some ten years ago ; siuce that time he has published many 

 thousands of accurate observations, partly to solve doubts in the other 

 work, partly for the study of proper motions. There is yet a volume 

 of these investigations unpublished. The seven published volumes of 

 Bonn observations contain these zones, the calculations of proper 

 motion for four or five hundred stars, his observations on variable 

 stars, and a very valuable series of ei-rata to the principal star- 

 catalogues. 



' He was remarkable for his skill in detecting errors in the older 

 observations ; and his account of the curious mistakes into which his 

 rapid and impatient master Bessel occasionally fell, when the slower 

 Busch was a little tardy in reading microscopes, is quite amusing. 

 And in another place his detections of the peculiar errors committed 

 by Lalande and his friends, in reading off their numbers aloud in 

 French, is also entertaining. 



Argelander was the promoter of the scheme now in progress for a 



