372 LEADING AMERICAN MEN OF SCIENCE 



The new transit circle arrived in October, 1865, and to his great 

 delight, Newcomb was also given charge of it. Then it was 

 that he began the work of determining the error in the right ascen- 

 sion of stars which he believed had crept into the modern observa- 

 tions made in Greenwich, Paris, and Washington and which 

 prevented stars that were on opposite quarters of the heavens from 

 agreeing. For more than three years this undertaking occupied 

 his close attention, and in 1869 he found after working up his 

 observations that the error he had suspected in the adopted posi- 

 tions of the stars was real. This investigation was conspicuously 

 valuable in developing the fact that very difficult mathematical 

 investigations were needed to unravel one of the greatest mysteries 

 of astronomy, that of the moon's motion. Before, however, passing 

 to the consideration of his scientific work more in detail it should 

 be mentioned that he continued at the observatory until 1877, 

 when he became senior professor of mathematics in the U. S. 

 Navy with the relative rank of captain. 



The year 1877 was perhaps the most important one in New- 

 comb's life. With all the strength of his powerful intellect, with 

 all the accumulated experience that constitutes wisdom, with the 

 prosperity that comes with success, and with an appointment 

 that placed him at the head of a great scientific bureau he was 

 indeed at the very zenith of his career. On September 15, 1877, 

 he was assigned to the charge of the Nautical Almanac office, 

 and of this appointment he says: "the change was one of the hap- 

 piest in my life." He adds: 



"I was now in a position of recognized responsibility, where my 

 recommendations met with respect due to that responsibility, 

 where I could make plans with the assurance of being able to 

 carry them out, and where the countless annoyances of being 

 looked upon as an important factor in work where there was no 

 chance of my being such would no longer exist. Practically I had 

 complete control of the work of the office, and was thus, meta- 

 phorically speaking, able to work with untied hands." 



He found the office in a rather dilapidated old dwelling-house, 

 not very far away from the observatory, in one of those doubtful 



