The Dalton Main Collieries Limited became a public company which appeared on the London Stock Exchange in December 1899. The company was set up by John Brown and Company with the aim of purchasing Roundwood Colliery at Parkgate and to purchase land between Thrybergh and Ravenfield, known as Silverwood, and sink a new deep colliery there. By the time production was in full swing at Silverwood in 1909 John Brown were sole proprietors of the Dalton Main Company.