64 James Craig Watson. 
charge of an expedition to Peking, China, to observe the 
transit of Venus. His observations were favored by the 
weather and conducted with consummate skill. The results, 
added Juewa, the eighteenth. In 1876, he was one of the 
Judges of Awards at the Centennial Exposition, and wrote the 
celebrated ‘Report on Horological Instruments.” In 1878 
also appeared his Tables for the Calculation of Simple and 
Compound Interest—a work which, in spite of the subject, is 
marked by great originality, and demanded a vast amount of 
wearisome labor. e same year he was: sent by the General 
Government in charge of an expedition to Wyoming, to observe 
the total solar eclipse. Professor Watson, having long enter- 
tained a belief in the existence of an intra-mercurial planet, as 
well as of an extra-neptunian one, gave special attention, at this 
time, to a search for the former, and was the first astronomer to 
note certainly (July 29, 1878) the existence and position of the 
planet Vulcan. He also satisfied himself of the existence of a 
second intra-mercurial planet. This brought the number of 
his original planetary discoveries to twenty-six (including one 
lost July 29, 1873, and two anticipated). He was now anl- 
mated by an intense desire to control instruments of suitable 
power and adjustment to confirm his last observations, an 
enable him to detect the outlying planet beyond Neptune. 
Coincidently came the invitation to assume the charge of the 
as 
inadequate appreciation of the honor shed upon the State by 
such a name as Watson’s. Reluctantly, but sustained by @ 
high and noble aspiration, he removed, in the summer of 1879 
to Madison, and immediately devoted himself with intens¢ 
energy to remodeling the observatory structure, and introduc 
ing some original provisions thought to be suited to the special 
researches on which he was bent. A cellar twenty feet deep 
