348 
ANNALS NEW YORK ACADEMY OF SCIENCES 
comb wished always to be accounted a mathematician, his work seems 
motived by its possible application to astronomy, and no very weighty con¬ 
tribution from his pen has accrued to pure mathematics. 
While still an assistant in the office of the American Epliemeris, then at 
Cambridge, Mass., Professor Newcomb began his career as an astronomer 
by discussing the question of the origin of the minor planets. Induced by 
too great confidence in the law of Bode as to the relations* of the mean dis¬ 
tances of the major planets, Olbers had ventured to put forward the hypoth¬ 
esis that the minor planets were the fragments resulting from the disruption 
of a single major planet. This hypothesis necessitated the condition that 
the orbits of the minor planets at some past epoch must have had a point in 
common. By computing the secular variations of the elements of the 
minor planets, Professor Newcomb showed that at no time could this condi¬ 
tion have been fulfilled. Thus there was no reason for entertaining the 
theory of Olbers. 
After Professor Newcomb’s appointment to a professorship of mathe¬ 
matics in the U. S. Navy and his removal to Washington, he was much 
engaged with the instruments of the U. S. Naval Observatory, chiefly the 
Pistor and Martin’s transit circle, but found time to investigate the distance 
of the sun, concluded from all the methods. His result for the constant of 
solar parallax was 8". 848, a value adopted in nearly all the ephemerides for 
quite a lengthy period. It is too large chiefly on account of the large weight 
attributed to the determination from Mars, w T hose observation is subject to 
systematic errors, at that time unsuspected. 
About the same time, Professor Newcomb undertook the investigation 
of the orbit of Neptune and constructed general tables of its motion. As 
material he had the two observations of Lalande and those of eighteen years 
following the discovery of the planet. This investigation, published in the 
Smithsonian Contributions to Knowledge, met an urgent need of practical 
astronomy at that time. 
As the secure reduction of astronomical observations is a matter of prime 
importance, Professor NeAvcomb contributed to the Washington Observa¬ 
tions for 1870 an appendix dealing with the right ascensions of the equatorial 
fundamental stars. His aim was to eliminate as far as possible systematic 
errors of a personal or local nature and thus obtain a homogeneous system. 
This was an admirably conducted investigation and has served as a founda¬ 
tion for whatever has been since accomplished in this subject. 
The elegant method of treating the motion of the moon by Delaunay, 
published in 1860, led Professor Ne\A r comb to consider this subject; thus we 
have his memoir in Liouville’s Journal for 1871 on the planetary perturba¬ 
tions of the moon. The investigation is very neat, regard being had to the 
