Paragon Mill, at eight storeys, was the world's tallest cast iron structure when it was built.

[5] Salvin's ran a room and power mill (1780) on the Shooters Brook in Ancoats, and here the partnership of Sandford, McConnel and Kennedy was formed.

Salvin's factory failed to get enough power from Shooters Brook, so he improved the head of water with a Savery type steam pump.

On 2 March 1795, the partnership was terminated; McConnel and Kennedy moved to other premises in Derby Street.

[7] James McConnel, served an apprenticeship with William Cannan in Chowbent, and moved to Manchester in 1788 to work for Alexander Egelsom, a weft and twist dealer with a cotton spinning establishment on Newton Street, Ancoats.

By 1797, McConnel and Kennedy had built a mill with steam powered spinning mules.

[8] Between 1801 and 1803, Long Mill was built, it was eight storeys tall, 30 bays long by four bays deep, its 45 hp Boulton and Watt engine was placed in an internal engine house on the south side of the mill but the boilers were external.

William Fairbairn and James Lillie, designed and installed the shafting, which was unusual as the wings of the mill were offset at 15 degrees to the right angle.

John Kennedy retired in 1826, and the firm traded as McConnel & McConnel Co.[10] Alexis de Tocqueville, described Redhill Street Mill in 1835 as "... a place where some 1,500 workers, labouring 69 hours a week, with an average wage of 11 shillings, and where three-quarters of the workers are women and children".

They had cast iron columns supporting transverse steel beams and reinforced concrete floors.