|Author:||William Ellis, Assistant at the Royal Observatory|
|About||Both William Ellis and his father worked at the Observatory. Between them, they were at the Observatory from 1825–1893 when William retired. Published in two parts in The Observatory, Vol 20, p.312–318 & p.380–386 (1897).
Click here to read part 1 as originally published.
Click here to read part 2 as originally published.