238 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
Nautical Almanac office he added those of professor of mathematics 
and astronomy at the Johns Hopkins University and editor of the 
American Journal of Mathematics. In what foilows no attempt will 
be made to give more than the briefest outline of the more important 
of his astronomical activities. 
The first work that called attention to his genius for research was 
carried out in Cambridge while he was an assistant in the Nautical 
Almanac office there. The final results were communicated in 1860 
to the American Academy of Arts and Sciences in a paper showing, 
among other things, that so far as present theory could determine, 
the orbits of the asteroids had never passed through any common 
point of intersection. There was thus no evidence that these little 
planets were fragments of a larger planet which had suffered a 
cataclysm at some epoch in the distant past, as suggested by Olbers. 
In 1862 the 8-inch transit circle of the Naval Observatory was 
received and placed in charge of Professor Newcomb, who proceeded 
to observe the stars of the American Ephemeris and other miscel- 
laneous stars. During 1866 and 1867 the observing programme was 
so arranged that as far as possible groups of stars were observed 
about twelve hours apart in order to determine the systematic errors 
of the star places given in the Ephemeris, and thus obtain results 
independent of previous observers. In the volume of Washington 
observations for 1870 Professor Newcomb published a memoir on the 
right ascensions of the equatorial fundamental stars and the correc- 
tions necessary to reduce the right ascensions of different star cata- 
logues to a mean homogeneous system. In the first volume of the 
Astronomical Papers of the American Ephemeris, a magnificent series 
of volumes founded by Professor Newcomb and continued by him 
curing his directorship of the Nautical Almanac office, he published 
another fundamental catalogue, this time giving both right ascensions 
and declinations, derived from all the data then available, as had been 
the catalogue previously mentioned. And finally, in the eighth vol- 
ume, is given a new determination of the precessional constant and a 
catalogue of fundamental stars for the epochs 1875 and 1900, reduced 
to an absolute system. This catalogue contains no less than 1,596 
stars and is a masterpiece of exhaustive research. The positions 
given are likely to remain the standard for some time to come, prob- 
ably at least until the observations of Piazzi, Maskelyne, Bessel, and 
Pond have been re-reduced. They have already been introduced into 
the principal national ephemerides of the world. 
Professor Newcomb at an early date became interested in the 
question of the sun’s parallax, and in 1869 published an investigation 
based upon all the data then available. The result at once became 
the standard and so remained for many years. Later, as a member 
of the Transit of Venus Commission, he took an active part in pre- 
