ACADEMY OF SCIENCES] BIOGRAPHY. 9 



reminiscences he has written generously of his chief assistants in the work of the Almanac 

 office, and space should be taken for a few quotations: 



Perhaps the most eminent and interesting man associated with me during this period was Mr. George W. Hill, who 

 will easily rank as the greatest master of mathematical astronomy during the last quarter of the nineteenth century. 

 * * * The part assigned to Hill was about the most difficult in the whole work — the theory of Jupiter and Saturn 

 Owing to the great mass of these "giant planets," the inequalities of their motion, especially in the case of Saturn, 

 affected by the attraction of Jupiter, are greater than in the case of the other planets. Leverrier failed to attain the 

 necessary exactness in his investigation of their motion. 



Hill had done some work on the subject at his home in Kyack Turnpike before I took charge of the office. He 

 now moved to Washington, and seriously began the complicated numerical calculations which his task involved. 

 I urged that he should accept the assistance of less skilled computers; but he declined it from a desire to do the entire 

 work himself. Computers to make the duplicate computations necessary to guard against accidental numerical errors 

 on his part were all that he required. He labored almost incessantly for about 10 years, when he handed in the manu- 

 script of what now forms Volume IV 6 of the Astronomical Papers. * * * And here was perhaps the greatest 

 living master in the highest and most difficult field of astronomy, winning world-wide recognition for his country in 

 the science, and receiving the salary of a department clerk. I never wrestled harder with a superior than I did with 

 Hon. R. W. Thompson, Secretary of the Navy, about 1880, to induce him to raise Mr. Hill 's salary from §1,200 to SI, 400. 

 It goes without saying that Hill took even less interest in the matter than I did. He did not work for pay, but for the 

 love of science. * * * That I could not secure for him at least the highest official consideration is among the regret- 

 ful memories of my official life. 



Of John Meier he says : 



He was the most perfect example of a mathematical machine that I ever had at command. 

 Of Cleveland Keith: 



A man of totally different blood, the best in fact, entered the office shortly before Meier broke down. This was 

 Mr. Cleveland Keith, son of Prof. Reuel Keith, who was one of the professors at the observatory when it was started. 

 Hi3 patience and ability led to his gradually taking the place of a foreman in supervising the work pertaining to the 

 reduction of the observations, and the construction of the tables of the planets. Without his help, I fear, I should 

 never have brought the tables to a conclusion. 



In 1894 I had succeeded in bringing so much of the work as pertained to the reduction of the observations and the 

 determination of the elements of the planets to a conclusion. So far as the larger planets were concerned, it only 

 remained to construct the necessary tables, which, however, would be a work of several years. 



The program was now interrupted by new duties assumed in connection with placing the 

 nautical almanacs of the different nations upon a homogeneous basis, in accordance with plans 

 and decisions made by the heads of the various almanac offices, at a conference in Paris in May, 

 1896. It later transpired that some of the leading American astronomers were unwilling to 

 approve, adopt, and abide by these decisions, and the full fruits of the plan were not realized in 

 the American Ephemeris. The subject was further complicated by the automatic retirement of 

 Prof. Newcomb on completing his sixty-second year, March 12, 1897. It became a serious 

 question whether he would be able to finish the international program, and also the planetary 

 tables, after his successor should have assumed the duties of the Almanac office. An arrange- 

 ment was eventually effected under which computers, provided for by a small congressional 

 appropriation, "were not to be prohibited from consulting me in its prosecution." 



Speaking of the Nautical Almanac office, Prof. Newcomb has written: 

 In conducting my office also, the utmost economy was always studied. The increase in the annual appropriations 

 for which I asked was so small that, when I left the office in 1S97, they were just about the same as they were back in 

 the fifties, when it was first established. The necessary funds were saved by economical administration. All this 

 was done with a feeling that, after my retirement, the satisfaction with which one could look back on such a policy 

 would be enhanced by a feeling on the part of the representatives of the public that the work I had done must be worthy 

 of having some pains taken to secure its continuance in the same spirit. * * * The work which I most regretted to 

 leave unfinished was that on the motion of the moon. As I have already said, this work is (in 1903) complete to 1750. 

 The computations for carrying it on from 1750 to the present time were perhaps three-fourths done when I had to lay 

 them aside. In 1902, when the Carnegie Institution was organized, it made a grant for supplying me with the computing 

 assistance and other facilities necessary for the work, and the Secretary of the Navy allowed me the use of 

 the old computations. Under such auspices the work was recommenced in March, 1903. 



It is a matter for universal congratulation that Prof. Newcomb was able to complete the 

 work of his great program on the motion of the moon, under the patronage of the Carnegie 

 Institution of Washington, and to prepare the results for publication, less than a month before 



« A New Theory of Jupiter and Saturn, by G. W. Hill. 



