The carpet manufactory at Dean Clough was commenced by John Crossley in a small way, but it became, under the management of John Crossley, jun., Joseph Crossley, and Francis Crossley, who constituted the firm of J. Crossley & Sons, the largest concern of its kind in the world. Its buildings covered an area of , and the firm gave employment to between five and six thousand. Its rapid growth was by application of steam power and machinery to the production of carpets. The Crossley firm acquired patents and then devised and patented improvements which placed them in advance of the rest of the trade. One loom, the patent of which became their property, was found capable of weaving about six times as much as could be produced by the old hand loom. Manufacturers of tapestry and Brussels carpets applied to Messrs. Crossley for licences to work their patents, and large sums accrued to them from royalties alone.