SIMBAD references

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.