Harvard-Smithsonian Center
for Astrophysics, 60 Garden Street, Cambridge, MA 02138
Received 13 April 1987
Abstract
In 1862, Alvan Graham Clark
discovered the predicted companion of Sirius while helping his father test
their new 18-1/2 inch lens in Cambridgeport, Massachusetts. Deborah Warner, in
her book, Alvan Clark & Sons: Artists in Optics, calls the discovery "a classic case of
serendipity" and states that although the companion "had been
frequently sought by others," Alvan Graham Clark "was probably
unaware of these previous researches." By quoting an undocumented story
about the event given in a secondary source, Warner paints a picture of the
discovery that raises some practical questions: