SAMUEL PIERPONT LANGLEY. 
3 
all scientific institutions. This European journey had an- 
other notable influence in familiarizing him with the conti- 
nental languages, especially French, in which he acquired 
great proficiency. 
Upon his return to Boston, the then director of the Har- 
vard College observatory, Professor Joseph Winlock, invited 
him to become an assistant in that observatory ; and so, at 
the age of thirty, without any previous preparation, but 
with an accurately trained eye and hand and experience 
in observation, both in his native country and in Europe, 
at that time by no means usual, he was enabled to realize 
the dream of his early life and devote himself to scientific 
pursuits in that department which had most strongly inter- 
ested him. 
His work with Professor Winlock was of brief duration, 
though even after leaving Cambridge he continued the asso- 
ciation with him for some time. The attachment formed 
then was a strong one, and he bore in grateful remembrance 
the man who had given him his first opportunity to realize 
his early ambitions. In after years, when he came to Wash- 
ington, he chose as one of his principal assistants here a 
son of Joseph Winlock, William Crawford Winlock, also 
an astronomer and for a number of years the Secretary of 
this Society, and to the end of his life he held these two men 
in affectionate memory. 
In 1866 he went to the U. S. Naval Academy at Annapolis, 
with the title of assistant professor of mathematics, but with 
the understanding that his duties would lie principally in the 
reorganization of the small observatory whose work had been 
interrupted by the Civil War. There he remounted and put 
into service the instruments and equipped the observatory 
for practical and scientific work. 
His stay at Annapolis, though fruitful in this regard, was 
a brief one, for at the end of the same year he was called to 
the Western University of Pennsylvania, where he became 
professor of astronomy and physics and director of the 
Allegheny observatory. This position he held for twenty 
years, and here it was that he carried on scientific labors of 
