302.
[8] This excellent instrument is now in the possession of my son-in-law, Dr.Hartree, of Leigh, near Tunbridge.
[9] An interesting account of Mr.Alvan Clark is given in Professor Newcomb's 'Popular Astronomy,' p.

137.
[10] A photographic representation of this remarkable telescope is given as the frontispiece to Mr.Lockyer's Stargazing, Past and Present; and a full description of the instrument is given in the text of the same work.

This refracting telescope did not long remain the largest.

Mr.Alvan Clark was commissioned to erect a larger equatorial for Washington Observatory; the object-glass (the rough disks of which were also furnished by Messrs.

Chance of Birmingham) exceeding in aperture that of Mr.Cooke's by only one inch.