He spent some ten years in grinding lenses, and was at length enabled to produce objectives equal in quality to any ever made.
In 1853, the Rev.W.E.Dawes--one of Mr.Cooke's customers--purchased an object-glass from Mr.Clark.

It was so satisfactory that he ordered several others, and finally an entire telescope.

The American artist then began to be appreciated in his own country.

In 1860 he received an order for a refractor of eighteen inches aperture, three inches greater than the largest which had up to that time been made.

This telescope was intended for the Observatory of Mississippi; but the Civil War prevented its being removed to the South; and the telescope was sold to the Astronomical Society of Chicago and mounted in the Observatory of that city.
And now comes in the rivalry of Mr.Cooke of York, or rather of his patron, Mr.Newall of Gateshead.