[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. This was finished and mounted in November, 1873. Another instrument of similar size and power was manufactured by Mr. Clark for the University of Virginia. But these instruments did not long maintain their supremacy. In 1881, Mr. Howard Grubb, of Dublin, manufactured a still larger instrument for the Austrian Government--the object-glass being of twenty-seven inches aperture. But Mr. Alvan Clark was not to be beaten. In 1882, he supplied the Russian Government with the largest refracting telescope in existence the object-glass being of thirty inches diameter. Even this, however, is to be surpassed by the lens which Mr. Clark has in hand for the Lick Observatory (California), which is to have a clear aperture of three feet in diameter. [11] Since the above passage was written and in type, I have seen (in September 1884) the reflecting telescope referred to at pp. 357-8. It was mounted on its cast-iron equatorial stand, and at work in the field adjoining the village green at Bainbridge, Yorkshire. The mirror of the telescope is 8 inches in diameter; its focal length, 5 feet; and the tube in which it is mounted, about 6 feet long. The instrument seemed to me to have an excellent defining power.