Three of the London makers had before possessed a monopoly of the business; but now the trade was thrown open by the enterprise of Cooke of York.

He proceeded to erect a complete factory--the Buckingham Street works.
His brother took charge of the grinding and polishing of the lenses, while his sons attended to the mechanism of the workshop; but Cooke himself was the master spirit of the whole concern.

Everything that he did was good and accurate.

His clocks were about the best that could be made.

He carried out his clock-making business with the same zeal that he devoted to the perfection of his achromatic telescopes.